Employee Benefits and Share-Based Compensation - Stock Repurchase Program (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Aug. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchased (shares)	0	0	1,424
Treasury stock, value			$ 50,020
The 2016 Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase, authorized amount				$ 50,000
2016 and 2014 Share Repurchase Programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase, remaining authorized repurchase amount	$ 54,900	$ 54,900