Share-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Stock Options
Beginning balance (in shares)	668	845
Granted (in shares)	0	0
Exercised (in shares)	(225)	(166)
Expired (in shares)	0	0
Forfeited/Canceled (in shares)	0	(11)
Ending balance (in shares)	443	668
Exercisable at December 31, 2016 (in shares)	443
Vested and expected to vest at December 31, 2016 (in shares)	443
Weighted- Average Exercise Price
Beginning balance (in dollars per share)	$ 17.91	$ 17.54
Granted (in dollars per share)	0.00	0.00
Exercised (in dollars per share)	17.66	16.13
Expired (in dollars per share)	0.00	0.00
Forfeited/Canceled (in dollars per share)	0.00	15.98
Ending balance (in dollars per share)	18.05	$ 17.91
Exercisable at December 31, 2016 (in dollars per share)	18.05
Vested and expected to vest at December 31, 2016 (in dollars per share)	$ 18.05
Weighted-Average Remaining Contractual Term (Years), Outstanding	10 months 24 days	1 year 8 months 12 days
Weighted-Average Remaining Contractual Term (Years), Exercisable	10 months 24 days
Weighted-Average Remaining Contractual Term (Years), Vested and expected to vest	10 months 24 days
Aggregate Intrinsic Value, Outstanding	$ 22,430	$ 24,768
Aggregate Intrinsic Value, Exercisable	22,430
Aggregate Intrinsic Value, Vested and expected to vest	$ 22,430