Stock-Based Awards - Restricted Stock Units (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Additional Information
Compensation expense recognized	$ 54,699	$ 43,081	$ 33,680
Restricted stock units
Nonvested Shares Subject to Performance Based Awards, Number of Shares
Number of shares, outstanding at beginning of period (in shares)	2,460
Number of shares, granted (in shares)	1,859
Number of shares, forfeited (in shares)	(367)
Number of shares, vested (in shares)	(698)
Number of shares, outstanding at period end (in share)	3,254	2,460
Nonvested Shares Subject to Performance Based Awards, Weighted Average Grant Date Fair Value
Weighted average grant date fair value, outstanding at beginning of period (in usd per share)	$ 34.71
Weighted average grant date fair value, granted (in usd per share)	37.49
Weighted average grant date fair value, forfeited (in usd per share)	34.63
Weighted average grant date fair value, vested (in usd per share)	34.50
Weighted average grant date fair value, outstanding at period end (in usd per share)	$ 36.35	$ 34.71
Additional Information
Compensation expense recognized	$ 31,900	$ 15,000	$ 5,700
Unrecognized compensation expense related to nonvested restricted stock units	$ 91,600
Unrecognized compensation expense, weighted-average period of recognition	2 years 11 months 1 day