v3.3.1.900
Equity Stock-based compensation (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Stock Based Compensation [Abstract]      
Stock-based compensation expense $ 16,321 $ 17,580 $ 13,334
Deferred tax benefit $ 5,342 $ 4,054 $ 434