Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2015	$ 719,546	$ 105,563	$ 365,981	$ 378,081	$ (2,386)	$ (127,693)
Beginning balance, shares at Dec. 31, 2015		88,961,268
Net Income	12,473			12,473
Other comprehensive income (loss)	7,664				7,664
Dividends, declared (USD per share)	(6,224)			(6,224)
Treasury stock acquired	(488)					(488)
Treasury stock acquired, shares		(55,301)
Restricted stock	343	$ 0	109	0		234
Restricted stock, shares		53,348
Ending balance at Mar. 31, 2016	733,314	$ 105,563	366,090	384,330	5,278	(127,947)
Ending balance, shares at Mar. 31, 2016		88,959,315
Beginning balance at Dec. 31, 2016	$ 749,929	$ 105,563	366,426	412,764	(7,027)	(127,797)
Beginning balance, shares at Dec. 31, 2016	88,961,268	89,007,077
Net Income	$ 15,888			15,888
Other comprehensive income (loss)	944				944
Dividends, declared (USD per share)	(7,119)			(7,119)
Treasury stock acquired	(1,102)					(1,102)
Treasury stock acquired, shares		(78,632)
Restricted stock	197	$ 0	137	0		60
Restricted stock, shares		26,000
Ending balance at Mar. 31, 2017	$ 760,995	$ 105,563	367,607	421,533	$ (6,083)	(127,625)
Ending balance, shares at Mar. 31, 2017	89,113,083	89,113,083
Stock Issued During Period, Shares, Treasury Stock Reissued		158,638
Stock Issued During Period, Value, Treasury Stock Reissued	$ 2,258		$ 1,044	$ 0		$ 1,214