Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total		Common Stock [Member]	Additional Paid-In Capital	Retained Earnings	Unallocated ESOP Shares	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Stockholders' Equity, Beginning Balance at Dec. 31, 2014		$ 200,926		$ 17,079	$ 239,721	$ 29,458	$ (1,450)	$ (7,166)	$ (76,716)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		12,160		0	0	12,160	0	0	0
Other Comprehensive Income		(5)	[1],[2]	0	0	0	0	(5)	0
Cash Dividends Paid	[3]	(6,315)		0	0	(6,315)	0	0	0
Stock Options Exercised, Net		70		0	40	0	0	0	30
Shares Issued Under the Directors' Stock Plan		118		0	73	0	0	0	45
Shares Issued Under the Employee Stock Purchase Plan		249		0	153	0	0	0	96
Stock-Based Compensation Expense		157		0	157	0	0	0	0
Purchases of Treasury Stock		(762)		0	0	0	0	0	(762)
Allocation of ESOP Stock		349		0	(99)	0	(250)	0	0
Stockholders' Equity, Ending Balance at Jun. 30, 2015		206,947		17,079	240,243	35,303	(1,200)	(7,171)	(77,307)
Stockholders' Equity, Beginning Balance at Dec. 31, 2015		213,971		17,421	250,680	32,139	(1,100)	(7,972)	(77,197)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		13,196		0	0	13,196	0	0	0
Other Comprehensive Income		3,230	[1],[2]	0	0	0	0	3,230	0
Cash Dividends Paid		(6,483)		0	0	(6,483)	0	0	0
Stock Options Exercised, Net		1,321		0	732	0	0	0	589
Shares Issued Under the Directors' Stock Plan		104		0	69	0	0	0	35
Shares Issued Under the Employee Stock Purchase Plan		250		0	157	0	0	0	93
Shares Issued for Dividend Reinvestment Plans		874		0	565	0	0	0	309
Stock-Based Compensation Expense		145		0	145	0	0	0	0
Tax Benefit for Disposition of Stock Options		46		0	46	0	0	0	0
Purchases of Treasury Stock		(1,648)		0	0	0	0	0	(1,648)
Allocation of ESOP Stock		367		0	(117)	0	(250)	0	0
Stockholders' Equity, Ending Balance at Jun. 30, 2016		$ 225,373		$ 17,421	$ 252,511	$ 38,852	$ (850)	$ (4,742)	$ (77,819)

[1] All amounts are net of tax. Amounts in parentheses indicate debits.

[2] These accumulated other comprehensive income components are included in the computation of net periodic pension cost.

[3] Share and Per Share Amounts have been restated for the September 28, 2015 2% stock dividend.