Securities (Cumulative life credit losses recognized in earnings) (Details) (Private-label CMOs [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Private-label CMOs [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Cumulative OTTI credit losses, beginning balance	$ 252	$ 2,940	$ 2,949	$ 2,625
Additions for which OTTI was not previously recognized	0	0	0	0
Additional increases for OTTI previously recognized when there is no intent to sell and no requirement to sell before recovery of amortized cost basis	0	0	649	315
Reduction due to credit impaired securities sold	(112)	0	(3,458)	0
Cumulative OTTI credit losses recognized for securities still held, ending balance	$ 140	$ 2,940	$ 140	$ 2,940