Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Benefit Plans	Dec. 31, 2012 Benefit Plans	Mar. 31, 2013 Unrealized Gains on Securities Available for Sale	Mar. 31, 2013 Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	$ 376		$ (7,458)	$ (7,458)	$ 8,764	$ (930)
Other comprehensive income (loss) before reclassifications	(1,964)				(1,982)	18
Amounts reclassified from accumulated other comprehensive income	45					45
Other comprehensive loss, net of tax	(1,919)	(133)			(1,982)	63
Balance at the end of the period	$ (1,543)	$ (2,882)	$ (7,458)	$ (7,458)	$ 6,782	$ (867)