Quarterly report pursuant to Section 13 or 15(d)

Debt (Conv) (Details)

v3.5.0.2
Debt (Conv) (Details) - Convertible Notes
$ / shares in Units, $ in Thousands
Dec. 15, 2014
USD ($)
item
$ / shares
Sep. 30, 2016
USD ($)
$ / shares
Dec. 31, 2015
USD ($)
Debt      
Face amount $ 172,500    
Net proceeds from offering $ 166,967    
Interest rate (as a percent) 1.75%    
Repurchase percentage of principal (as a percent) 100.00%    
Conversion rate 0.0159022    
Principal amount | $ / shares $ 1    
Conversion price (in dollars per share) | $ / shares $ 62.88 $ 62.88  
Threshold trading days (in days) | item 20    
Consecutive trading days 30 days    
Threshold percentage of stock price trigger (as a percent) 130.00%    
Threshold business days 5 days    
Threshold consecutive trading-day period 5 days    
Threshold percentage of trading price trigger (as a percent) 98.00%    
Allocated to equity components $ 26,618    
Offering costs 882    
Discount $ 27,500 $ 18,470 $ 22,367
Effective interest rate on the liability component (as a percent)   6.00%