Comprehensive Income/Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
COMPREHENSIVE INCOME
Change in fair value of securities available for sale, pre tax amount	$ (1,232)		$ (246)
Change in fair value of securities available for sale, tax (expense) benefit	(455)		(85)
Change in fair value of securities available for sale, after tax amount	(777)		(161)
Change in fair value of cash flow hedges, pre tax amount	(5)	[1]	53	[1]
Change in fair value of cash flow hedges, tax (expense) benefit	2		(22)
Change in fair value of cash flow hedges, after tax amount	(3)		31
Less: net cash flow hedge losses reclassified into earnings, pre tax amount	1,414		1,293
Less: net cash flow hedge losses reclassified into earnings, tax (expense) benefit	(578)		(528)
Less: net cash flow hedge losses reclassified into earnings, after tax amount	836		765
Net change in fair value of cash flow hedges, pre tax amount	1,409		1,346
Net change in fair value of cash flow hedges, tax (expense) benefit	576		550
Net change in fair value of cash flow hedges	833		796
Amortization of certain costs included in net periodic retirement costs, pre tax amount	22		39
Amortization of certain costs included in net periodic retirement costs, tax (expense) benefit	(21)		(16)
Amortization of certain costs included in net periodic retirement costs, after tax amount	1		23
Total other comprehensive income, pre tax amount	199		1,139
Total other comprehensive income, tax (expense) benefit	142		481
Total other comprehensive income	$ 57		$ 658

[1] Includes the remaining balance of a realized but unrecognized gain, net of tax, from the termination of interest rate swaps in June 2009. The original gain of $1.4 million, net of tax, will be recognized in earnings through December 2018, the original maturity date of the swap. The balance of this gain has amortized to $823,000 and $967,000 at March 31, 2013 and 2012, respectively.