Stock-Based Compensation (Tables)
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12 Months Ended |
Dec. 31, 2015 |
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| Stock-Based Compensation |
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| Schedule of employee stock-based compensation expense |
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Year Ended December 31,
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2015
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2014
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2013
|
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Employee stock-based compensation expense
|
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$
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15,161
|
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$
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11,423
|
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$
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8,738
|
|
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Tax effect on employee stock-based compensation expense
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(7,678)
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|
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(4,434)
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(3,196)
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Net effect on income
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$
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7,483
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$
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6,989
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$
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5,542
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| Schedule of weighted average assumptions used to value options granted |
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Year Ended December 31,
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2015
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2014
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2013
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Grant date fair value of options
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$
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19.06
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$
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16.81
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$
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6.11
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Volatility
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37.8
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%
|
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37.3
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%
|
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40.4
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%
|
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Risk-free interest rate
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|
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1.8
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%
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1.9
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%
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1.0
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%
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Dividend yield
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0.0
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%
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0.0
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%
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0.0
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%
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Expected term (in years)
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6.0
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6.0
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6.0
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| Summary of option activity under the Company's plans |
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Weighted-Average
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Weighted-
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Remaining
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Average
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Contractual Life
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Aggregate
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Options
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Exercise Price
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(Years)
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Intrinsic Value
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Outstanding as of December 31, 2012
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5,277,412
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$
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8.86
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6.3
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$
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26,885
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Granted
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190,413
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15.34
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Exercised
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(721,050)
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8.86
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Forfeited
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(109,304)
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12.33
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Outstanding as of December 31, 2013
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4,637,471
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9.04
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5.4
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|
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31,877
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Granted
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214,253
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42.92
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Exercised
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(573,298)
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9.05
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Forfeited
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(13,089)
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18.12
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Outstanding as of December 31, 2014
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4,265,337
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10.73
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4.7
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|
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163,830
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Granted
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358,087
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19.06
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Exercised
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(1,047,911)
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48.38
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Forfeited
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(41,722)
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7.90
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Outstanding as of December 31, 2015
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3,533,791
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41.10
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4.7
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61,199
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Options exercisable
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3,126,162
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15.03
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4.1
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60,364
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| Schedule of other information |
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Year Ended December 31,
|
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2015
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2014
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2013
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Total intrinsic value of options exercised
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$
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37,879
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$
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20,867
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$
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13,745
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Cash received from exercises of stock options
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8,279
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5,190
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6,400
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Cash received from issuance of restricted stock
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2
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1
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1
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| Summary of the activity for unvested restricted stock awards granted under the Company's plans |
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Weighted-
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Average Grant
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Number of
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Date Fair Value
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Shares
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per Share
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Outstanding as of December 31, 2012
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758,990
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$
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12.49
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Granted
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386,245
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19.54
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Vested
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(74,298)
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—
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Forfeited
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(169,386)
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12.69
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Outstanding as of December 31, 2013
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901,551
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16.50
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Granted
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360,834
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41.99
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Vested
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(143,264)
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—
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Forfeited
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(20,447)
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28.39
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Outstanding as of December 31, 2014
|
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1,098,674
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33.72
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Granted
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1,508,796
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|
34.55
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Vested
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(434,292)
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29.26
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Forfeited
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(19,967)
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|
38.58
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Outstanding as of December 31, 2015
|
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2,153,211
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|
|
35.63
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