Securities (Rollfoward of OTTI Recognized in Earnings) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Investments, Debt and Equity Securities [Abstract]
Credit related impairment losses on debt securities, beginning balance	$ 3,313	$ 2,946	$ 3,104	$ 2,913
Credit-related impairment losses on debt securities for which other-than-temporary impairment was not previously recognized	0	0	0	0
Additional increases to the amount of credit-related impairment loss on debt securities for which other-than-temporary impairment was previously recognized	0	158	209	191
Credit related impairment losses on debt securities, ending balance	$ 3,313	$ 3,104	$ 3,313	$ 3,104