Stock-Based Compensation - Equity Awards Outstanding and Exercisable (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock options
Options Outstanding
Options, outstanding at beginning of period (in shares)	1,344,795	1,421,520	1,383,332
Options, granted (in shares)	85,755	50,000	111,000
Options, assumed (in shares)	883,733
Options, exercised (in shares)	(271,703)	(74,531)	(57,464)
Options, forfeited (in shares)	(38,300)	(52,194)	(15,348)
Options, outstanding at end of period (in shares)	2,004,280	1,344,795	1,421,520	1,383,332
Options, exercisable (in shares)	1,680,525
Options, Weighted Average Exercise Price
Options, weighted average exercise price, beginning of period (in usd per share)	$ 11.70	$ 11.02	$ 10.06
Options, weighted average exercise price, granted (in usd per share)	26.72	27.48	20.18
Options, weighted average exercise price, assumed (in usd per share)	24.17
Options, weighted average exercise price, exercised (in usd per share)	19.20	6.83	4.59
Options, weighted average exercise price, forfeited (in usd per share)	20.51	15.21	14.25
Options, weighted average exercise price, end of period (in usd per share)	16.66	11.70	11.02	$ 10.06
Options, weighted average exercise price, exercisable (in usd per share)	16.62
Options, Weighted Average Grant Date Fair Value
Options, weighted average grant date fair value at beginning of period (in usd per share)	6.04	6.01	5.50
Options, weighted average grant date fair value, granted (in usd per share)	15.71	14.37	10.13
Options, weighted average grant date fair value, assumed (in usd per share)	5.71
Options, weighted average grant date fair value, exercised (in usd per share)	4.85	18.43	11.62
Options, weighted average grant date fair value, forfeited (in usd per share)	9.80	7.50	6.99
Options, weighted average grant date fair value at end of period (in usd per share)	6.06	$ 6.04	$ 6.01	$ 5.50
Options, weighted average grant date fair value, exercisable (in usd per share)	$ 5.49
Options, Weighted Average Remaining Term
Options, outstanding, weighted average remaining term	4 years 6 months 24 days	6 years 10 months 2 days	6 years 11 months 6 days	8 years 3 months 15 days
Options, exercisable, weighted average remaining contractual term	4 years 20 days
Stock options | Minimum
Options, Weighted Average Exercise Price
Options, weighted average exercise price, beginning of period (in usd per share)	$ 2.68	$ 2.28	$ 2.28
Options, weighted average exercise price, granted (in usd per share)	26.63	23.31	16.57
Options, weighted average exercise price, assumed (in usd per share)	10.94
Options, weighted average exercise price, exercised (in usd per share)	2.68	2.96	2.96
Options, weighted average exercise price, forfeited (in usd per share)	12.10	10.53	6.08
Options, weighted average exercise price, end of period (in usd per share)	2.68	2.68	2.28	$ 2.28
Options, weighted average exercise price, exercisable (in usd per share)	2.68
Stock options | Maximum
Options, Weighted Average Exercise Price
Options, weighted average exercise price, beginning of period (in usd per share)	27.87	23.19	18.07
Options, weighted average exercise price, granted (in usd per share)	27.47	31.28	23.19
Options, weighted average exercise price, assumed (in usd per share)	31.88
Options, weighted average exercise price, exercised (in usd per share)	29.79	17.10	6.08
Options, weighted average exercise price, forfeited (in usd per share)	27.87	31.28	16.57
Options, weighted average exercise price, end of period (in usd per share)	31.88	$ 27.87	$ 23.19	$ 18.07
Options, weighted average exercise price, exercisable (in usd per share)	$ 31.88
Stock appreciation rights
Shares
Outstanding at beginning of period (in shares)	0	0
Granted (in shares)	0
Assumed (in shares)	180,789
Vested (in shares)	(37,186)
Forfeited (in shares)	0
Outstanding at end of period (in shares)	143,603	0	0
Exercisable (in shares)	143,603
Weighted-Average Exercise Price
Outstanding at beginning of period (in usd per share)	$ 0.00
Granted (in usd per share)	0.00
Assumed (in usd per share)	15.61
Exercised (in usd per share)	15.61
Forfeited (in usd per share)	0.00
Outstanding at end of period (in usd per share)	15.61	$ 0.00
Exercisable (in usd per share)	$ 15.61
Outstanding, Weighted-Average Remaining Term	1 year 9 months 16 days
Exercisable, Weighted-Average Remaining Term	1 year 9 months 16 days
Restricted stock units
Shares
Outstanding at beginning of period (in shares)	692,823	901,655	883,816
Granted (in shares)	329,899	175,773	305,714
Assumed (in shares)	1,088,674
Vested (in shares)	(460,895)	(295,600)	(219,875)
Forfeited (in shares)	(92,060)	(89,005)	(68,000)
Outstanding at end of period (in shares)	1,558,441	692,823	901,655	883,816
Weighted-Average Grant Date Fair Value
Outstanding at beginning of period (in usd per share)	$ 15.23	$ 13.26	$ 11.31
Granted (in usd per share)	25.72	29.81	14.38
Assumed (in usd per share)	26.02
Exercised (in usd per share)	19.47	14.98	11.64
Forfeited (in usd per share)	27.24	14.94	10.65
Outstanding at end of period (in usd per share)	$ 23.01	$ 15.23	$ 13.26	$ 11.31
Performance-based restricted stock units
Shares
Outstanding at beginning of period (in shares)	1,563,951	450,000	0
Granted (in shares)	537,261	1,114,951	450,000
Assumed (in shares)	0
Vested (in shares)	(25,424)	0	0
Forfeited (in shares)	(88,728)	(1,000)	0
Outstanding at end of period (in shares)	1,987,060	1,563,951	450,000	0
Weighted-Average Grant Date Fair Value
Outstanding at beginning of period (in usd per share)	$ 20.86	$ 13.26	$ 0.00
Granted (in usd per share)	24.75	23.19	15.15
Assumed (in usd per share)	0.00
Exercised (in usd per share)	31.02	0.00	0.00
Forfeited (in usd per share)	28.15	27.61	0.00
Outstanding at end of period (in usd per share)	$ 21.47	$ 20.86	$ 13.26	$ 0.00