Share-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Stock Options
Beginning balance	845	1,031
Granted	0	0
Exercised	(166)	(177)
Expired	0	0
Forfeited/Canceled	(11)	(9)
Ending balance	668	845
Exercisable at December 31, 2015	552
Vested and expected to vest at December 31, 2015	668
Weighted- Average Exercise Price
Beginning balance (in USD per share)	$ 17.54	$ 17.28
Granted (in USD per share)	0.00	0.00
Exercised (in USD per share)	16.13	16.12
Expired (in USD per share)	0.00	0.00
Forfeited/Canceled (in USD per share)	15.98	15.98
Ending balance (in USD per share)	17.91	$ 17.54
Exercisable at December 31, 2015	17.70
Vested and expected to vest at December 31, 2015	$ 17.91
Weighted-Average Remaining Contractual Term (Years), Outstanding	1 year 8 months 12 days	2 years 256 days
Weighted-Average Remaining Contractual Term (Years), Exercisable	1 year 8 months 12 days
Weighted-Average Remaining Contractual Term (Years), Vested and expected to vest	1 year 8 months 12 days
Aggregate Intrinsic Value, Outstanding	$ 24,768	$ 26,400
Aggregate Intrinsic Value, Exercisable	20,601
Aggregate Intrinsic Value, Vested and expected to vest	$ 24,768