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Incentive Stock Plans - Summary of Additional Information for Stock Options (Details) - Stock Options - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Intrinsic value of options exercised $ 773 $ 4,044 $ 12,263
Fair value of options vested 1,938 3,054 2,558
Cash received from exercise of options $ 2,117 $ 5,579 $ 10,101