Stock-based Compensation and Benefits - (Summary of Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding Options, beginning	2,596,251
Granted, Options	167,163
Forfeited, Options	(21,480)
Surrendered, Options	(35,841)
Exercised, Options	(842)
Expired, Options	(1,499)
Outstanding Options, ending	2,703,752	2,596,251
Options fully vested and exercisable at end of period, Options	2,346,123
Options expected to vest, Options	352,816
Outstanding, Weighted Average Exercise Price, beginning	$ 19.84
Granted, Weighted Average Exercise Price	19.57
Forfeited, Weighted Average Exercise Price	18.86
Surrendered, Weighted Average Exercise Price	20.54
Exercised, Weighted Average Exercise Price	20.53
Expired, Weighted Average Exercise Price	19.82
Outstanding, Weighted Average Exercised Price, ending	19.82	$ 19.84
Options fully vested and exercisable at end of period, Weighted Average Exercise Price	19.91
Options expected to vest, Weighted Average Exercise Price	$ 19.34
Outstanding, Weighted Average Remaining Contractual Term in Years	4 years 6 months	4 years 9 months 7 days
Options fully vested and exercisable at end of period, weighted average remaining contractual term in years	3 years 9 months 29 days
Options expected to vest, Weighted Average Remaining Contractual Term in Years	8 years 5 months 23 days
Outstanding, Aggregate Intrinsic Value, beginning	$ 3,968
Outstanding, Aggregate Intrinsic Value, ending	1,433	$ 3,968
Aggregate intrinsic Value of Options fully vested and exercisable at end of period	364
Options expected to vest, Aggregate Intrinsic Value	$ 1,352