Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (17,605)	[1]	$ (323)
Other comprehensive income before reclassifications	3,292		(2,985)
Amounts reclassified from accumulated other comprehensive income	0		(1,592)
Other comprehensive income (loss), net of tax	3,292		(4,577)
Ending balance	(14,313)		(4,900)
Unrealized gains (losses) on available for sale securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(14,476)		3,650
Other comprehensive income before reclassifications	3,267		(2,985)
Amounts reclassified from accumulated other comprehensive income	0		(1,438)
Other comprehensive income (loss), net of tax	3,267		(4,423)
Ending balance	(11,209)		(773)
Interest rate swaps
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	0
Other comprehensive income before reclassifications	25
Amounts reclassified from accumulated other comprehensive income	0
Other comprehensive income (loss), net of tax	25
Ending balance	25
Defined benefit plan items [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(3,129)		(3,973)
Other comprehensive income before reclassifications	0		0
Amounts reclassified from accumulated other comprehensive income	0		(154)
Other comprehensive income (loss), net of tax	0		(154)
Ending balance	$ (3,129)		$ (4,127)

[1] Derived from audited consolidated financial statements