Comprehensive Income Changes in Accumulated Other Comprehensive Income By Component (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period	$ (4,075)	[1]	$ (8,324)	[1]	$ (4,373)	[1]	$ (8,462)	[1]
Other comprehensive income, before reclassifications, net of tax	514	[1]	(3,643)	[1]	755	[1]	(3,423)	[1]
Reclassification from Accumulated Other Comprehensive Income, net of tax	72	[1]	228	[1]	129	[1]	146	[1]
Other Comprehensive (Loss) Income	586	[1]	(3,415)	[1]	884	[1]	(3,277)	[1]
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(3,489)	[1]	(11,739)	[1]	(3,489)	[1]	(11,739)	[1]
Unrealized Gains and Losses on Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period	2,615	[1]	5,527	[1]	2,374	[1]	5,625	[1]
Other comprehensive income, before reclassifications, net of tax	514	[1]	(3,643)	[1]	755	[1]	(3,423)	[1]
Reclassification from Accumulated Other Comprehensive Income, net of tax	16	[1]	(8)	[1]	16	[1]	(326)	[1]
Other Comprehensive (Loss) Income	530	[1]	(3,651)	[1]	771	[1]	(3,749)	[1]
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	3,145	[1]	1,876	[1]	3,145	[1]	1,876	[1]
Amortization of Net Retirement Plan Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period	(6,627)	[1]	(13,800)	[1]	(6,697)	[1]	(14,036)	[1]
Other comprehensive income, before reclassifications, net of tax	0	[1]	0	[1]	0	[1]	0	[1]
Reclassification from Accumulated Other Comprehensive Income, net of tax	69	[1]	236	[1]	139	[1]	472	[1]
Other Comprehensive (Loss) Income	69	[1]	236	[1]	139	[1]	472	[1]
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	(6,558)	[1]	(13,564)	[1]	(6,558)	[1]	(13,564)	[1]
Accretion of Net Retirement Plan Prior Service Credit [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning of Period	(63)	[1]	(51)	[1]	(50)	[1]	(51)	[1]
Other comprehensive income, before reclassifications, net of tax	0	[1]	0	[1]	0	[1]	0	[1]
Reclassification from Accumulated Other Comprehensive Income, net of tax	(13)	[1]	0	[1]	(26)	[1]	0	[1]
Other Comprehensive (Loss) Income	(13)	[1]	0	[1]	(26)	[1]	0	[1]
Accumulated Other Comprehensive Income (Loss), Net of Tax, End of Period	$ (76)	[1]	$ (51)	[1]	$ (76)	[1]	$ (51)	[1]

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