Investment Securities (Narrative) (Details) (USD $)	6 Months Ended					3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 U.S. Treasury And Sponsored Entities Callable Notes [Member]	Jun. 30, 2013 U.S. Treasury And Sponsored Entities Callable Notes [Member] Minimum [Member]	Jun. 30, 2013 U.S. Treasury And Sponsored Entities Callable Notes [Member] Maximum [Member]	Jun. 30, 2013 U.S. Government Sponsored Entities Asset-Backed Securities [Member]	Jun. 30, 2013 U.S. Government Sponsored Entities Asset-Backed Securities [Member] Maximum [Member]
Schedule of Investments [Line Items]
Available for Sale expected to be called			$ 166,800,000
Other than Temporary Impairment Losses, Investments	0	54,000
Asset backed securities mortgage portfolio, term	15 years
Available-for-sale securities			594,700,000
Residential mortgage-backed securities and collateralized mortgage obligations, term				10 years	14 years		15 years
Proceeds from Sale of Available-for-sale Securities, Debt						$ 0