Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning of period	$ (4,509)	$ (13,803)
Other comprehensive income (loss)- before reclassifications	1,987	4,427
Amount reclassified from accumulated other comprehensive income	(165)	(76)
Other comprehensive income (loss), net of tax	1,822	4,351
Accumulated other comprehensive income (loss), net of tax, end of period	(2,687)	(9,452)
Net Unrealized Holding Gain (Loss) on Securities Available for Sale, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning of period	(3,693)	(18,078)
Other comprehensive income (loss)- before reclassifications	1,987	4,427
Amount reclassified from accumulated other comprehensive income	(149)	(4)
Other comprehensive income (loss), net of tax	1,838	4,423
Accumulated other comprehensive income (loss), net of tax, end of period	(1,855)	(13,655)
Net Change in Net Actuarial Loss (Gain) and Prior Service Credit on Pension and Postretirement Benefit Plans, Net of Tax [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning of period	(816)	4,275
Other comprehensive income (loss)- before reclassifications	0	0
Amount reclassified from accumulated other comprehensive income	(16)	(72)
Other comprehensive income (loss), net of tax	(16)	(72)
Accumulated other comprehensive income (loss), net of tax, end of period	$ (832)	$ 4,203