Consolidated Statement of Changes in Comprehensive Income (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statement of Changes in Comprehensive Income [Abstract]
Net income	$ 13,385,000	$ 13,375,000	$ 14,215,000
Securities available for sale
Change in net unrealized gain (loss) during the period	5,465,000	(9,955,000)	821,000
Income tax (benefit)	1,857,000	(3,384,000)	278,000
Securities available for sale	3,608,000	(6,571,000)	543,000
Reclassification adjustment for gains included in income	(616,000)	(441,000)	(604,000)
Income tax benefit	(209,000)	(150,000)	(205,000)
Reclassification	(407,000)	(291,000)	(399,000)
Change in unrealized loss on interest rate swap	0	200,000	148,000
Income tax expense	0	68,000	50,000
Interest rate swap	0	132,000	98,000
Change in unrecognized pension costs	(1,832,000)	1,325,000	(848,000)
Income tax expense (benefit)	(623,000)	451,000	(288,000)
Pension costs	(1,209,000)	874,000	(560,000)
Other comprehensive income (loss)	1,992,000	(5,856,000)	(318,000)
Comprehensive income	$ 15,377,000	$ 7,519,000	$ 13,897,000