Equity Compensation - Options Activity (Details) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Options outstanding at beginning of period (in shares) 2,942,783 3,600,132 4,533,782
Granted (in shares) 0 0 8,977
Excercised (in shares) (1,250) (172,218) (33,810)
Canceled (in shares) (398,801) (485,131) (908,817)
Options outstanding at end of period (in shares) 2,542,732 2,942,783 3,600,132
Weighted Average Exercise Price      
Options outstanding at beginning of period - Weighted Average Exercise Price (in dollars per share) $ 21.22 $ 22.74 $ 23.86
Granted - Weighted Average Exercise Price (in dollars per share) 0 0.00 16.71
Excercised - Weighted Average Exercise Price (in dollars per share) 13.82 13.95 14.16
Canceled - Weighted Average Exercise Price (in dollars per share) 21.47 34.98 28.57
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share) $ 21.19 $ 21.22 $ 22.74
Options exercisable at end of period (in shares) 2,513,614 2,656,983 2,954,082
Stock Options      
Weighted Average Exercise Price      
Options outstanding at end of period - Weighted Average Exercise Price (in dollars per share) $ 21.19    
Exercise price range, lower limit (in dollars per shares) 13.37 $ 13.37 $ 13.35
Exercise price range, upper limit (in dollars per shares) $ 33.36 $ 47.80 $ 47.80
Options available for grant at end of period (in shares) 3,891,121 2,659,562 3,654,426