|
Stock-Based Compensation (Tables)
|
12 Months Ended |
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Dec. 31, 2014
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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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|
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2014
|
|
2013
|
|
2012
|
|
|
Employee stock-based compensation expense
|
|
$
|
11,423
|
|
$
|
8,738
|
|
$
|
4,342
|
|
|
Tax effect on employee stock-based compensation expense
|
|
|
(4,434
|
)
|
|
(3,196
|
)
|
|
(1,643
|
)
|
|
|
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|
|
|
|
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Net effect on income
|
|
$
|
6,989
|
|
$
|
5,542
|
|
$
|
2,699
|
|
|
|
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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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2014
|
|
2013
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|
2012
|
|
|
Grant date fair value of options
|
|
$
|
16.81
|
|
$
|
6.11
|
|
$
|
4.96
|
|
|
Volatility
|
|
|
37.3
|
%
|
|
40.4
|
%
|
|
39.7
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%
|
|
Risk-free interest rate
|
|
|
1.9
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%
|
|
1.0
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%
|
|
1.2
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%
|
|
Dividend yield
|
|
|
0.0
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%
|
|
0.0
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%
|
|
0.0
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%
|
|
Expected term (in years)
|
|
|
6.0
|
|
|
6.0
|
|
|
6.0
|
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| Summary of option activity under the Company's plans |
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Options
|
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Weighted-
Average
Exercise Price
|
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Weighted-Average
Remaining
Contractual Life
(Years)
|
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Aggregate
Intrinsic Value
|
|
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Outstanding as of December 31, 2011
|
|
|
4,863,718
|
|
$
|
8.19
|
|
|
6.8
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$
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18,704
|
|
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Granted
|
|
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738,915
|
|
|
12.53
|
|
|
|
|
|
|
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Exercised
|
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(298,947
|
)
|
|
6.92
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|
|
|
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Forfeited
|
|
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(26,274
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)
|
|
11.03
|
|
|
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Outstanding as of December 31, 2012
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|
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5,277,412
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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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)
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8.86
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|
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Forfeited
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(109,304
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)
|
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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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)
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9.05
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Forfeited
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(13,089
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)
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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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163,830
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Options exercisable
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3,797,011
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8.72
|
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|
4.2
|
|
|
153,474
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| Schedule of other information |
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Year ended December 31,
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2014
|
|
2013
|
|
2012
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Total intrinsic value of options exercised
|
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$
|
20,867
|
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$
|
13,745
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$
|
1,611
|
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Cash received from exercises of stock options
|
|
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5,190
|
|
|
6,400
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|
2,069
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Cash received from issuance of restricted stock
|
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1
|
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|
1
|
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2,759
|
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| Summary of the activity for unvested restricted stock awards granted under the Company's plans |
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Number of
Shares
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Weighted-Average
Grant
Date Fair Value
per Share
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Balance at December 31, 2011
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73,820
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$
|
12.37
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Granted
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714,934
|
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|
12.50
|
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Vested
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(24,568
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)
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—
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Expired/cancelled
|
|
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(1,064
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)
|
|
12.45
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Forfeited
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(4,132
|
)
|
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12.49
|
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|
|
|
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Balance at December 31, 2012
|
|
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758,990
|
|
|
12.49
|
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Granted
|
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|
386,245
|
|
|
19.54
|
|
|
Vested
|
|
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(74,298
|
)
|
|
—
|
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Forfeited
|
|
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(169,386
|
)
|
|
12.69
|
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Balance at December 31, 2013
|
|
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901,551
|
|
|
16.50
|
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|
Granted
|
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|
360,834
|
|
|
41.99
|
|
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Vested
|
|
|
(143,264
|
)
|
|
—
|
|
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Forfeited
|
|
|
(20,447
|
)
|
|
28.39
|
|
|
|
|
|
|
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Balance at December 31, 2014
|
|
|
1,098,674
|
|
|
33.72
|
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