Earnings Per Share (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 10, 2016	Dec. 10, 2015	Jul. 30, 2015
Earnings Per Share [Line Items]
Payments for Repurchase of Common Stock	$ 27,582	$ 16,447	$ 542
Share Repurchase Program [Member]
Earnings Per Share [Line Items]
Stock Repurchased During Period, Shares	1,183,862
Treasury Stock Acquired, Average Cost Per Share	$ 22.84
Stock Repurchase Program, Authorized Amount					$ 67,500	$ 42,500
Adjustments To Additional Paid In Capital Under Stock Repurchased Costs	$ 27,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	24,800				$ 25,000	$ 25,000
Payments for Repurchase of Common Stock	$ 26,100
Share Repurchase Program [Member] | Subsequent Event [Member]
Earnings Per Share [Line Items]
Stock Repurchase Program, Authorized Amount				$ 142,500
Stock Repurchase Program, Remaining Authorized Repurchase Amount				$ 75,000