CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Capital	Retained earnings	Accumulated Other Comprehensive Income/(Loss)	Treasury Stock
Balance at Dec. 31, 2012	$ 372,122	$ 1,808	$ 69,989	$ 338,342	$ (7,472)	$ (30,545)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	31,534	0	0	31,534	0	0
Other comprehensive income (loss)	(6,497)	0	0	0	(6,497)	0
Contribution of shares to ESOP	611	3	770	0	0	(162)
Employee Stock Ownership Plan (ESOP), Cash Contributions to ESOP	1,218	0	315	0	0	903
Cash Dividends	(12,793)	0	0	(12,793)	0	0
Balance at Dec. 31, 2013	386,195	1,811	71,074	357,083	(13,969)	(29,804)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	33,772	0	0	33,772	0	0
Other comprehensive income (loss)	(560)	0	0	0	(560)	0
Treasury Stock, Value, Acquired, Cost Method	(14,633)	0	0	0	0	(14,633)
Contribution of shares to ESOP	1,072	4	1,068	0	0	0
Employee Stock Ownership Plan (ESOP), Cash Contributions to ESOP	1,253	0	263	0	0	990
Cash Dividends	(12,885)	0	0	(12,885)	0	0
Balance at Dec. 31, 2014	394,214	1,815	72,405	377,970	(14,529)	(43,447)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,196	0	0	30,196	0	0
Other comprehensive income (loss)	5,128	0	0	0	5,128	0
Treasury Stock, Value, Acquired, Cost Method	(8,698)	0	0	0	0	(8,698)
Contribution of shares to ESOP	715	2	713	0	0	0
Employee Stock Ownership Plan (ESOP), Cash Contributions to ESOP	1,294	0	278	0	0	1,016
Cash Dividends	(12,533)	0	0	(12,533)	0	0
Balance at Dec. 31, 2015	$ 410,316	$ 1,817	$ 73,396	$ 395,633	$ (9,401)	$ (51,129)