Stock-Based Compensation - Restricted Stock Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restricted stock unit activity
Total restricted stock units outstanding, beginning of period (in shares)	1,382,250	1,798,331	1,943,497
Granted (in shares)	67,060	62,530	316,500
Vested (in shares)	(60)	(125,280)	(278,000)
Forfeited and cancelled (in shares)	(113,250)	(353,331)	(183,666)
Total restricted stock units outstanding, end of period (in shares)	1,336,000	1,382,250	1,798,331
Weighted - Average Grant Date Fair Value
Total restricted stock units outstanding, beginning of period (in dollars per share)	$ 32.01	$ 32.31	$ 29.09
Granted (in dollars per share)	56.35	68.79	63.57
Vested (in dollars per share)	49.15	63.92	45.04
Forfeited and cancelled (in dollars per share)	45.12	28.76	32.77
Total restricted stock units outstanding, end of period (in dollars per share)	$ 32.11	$ 32.01	$ 32.31