Investment Securities (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Investments [Line Items]
Other than Temporary Impairment Losses, Investments	$ 0	$ 0	$ 17,000	$ 54,000
Asset backed securities mortgage portfolio, term			15 years
U.S. Treasury And Sponsored Entities Callable Notes [Member]
Schedule of Investments [Line Items]
Available for Sale expected to be called	25,100,000		25,100,000
Available-for-sale securities	605,700,000		605,700,000
U.S. Treasury And Sponsored Entities Callable Notes [Member] | Minimum [Member]
Schedule of Investments [Line Items]
Residential mortgage-backed securities and collateralized mortgage obligations, term	2 years		2 years
U.S. Treasury And Sponsored Entities Callable Notes [Member] | Maximum [Member]
Schedule of Investments [Line Items]
Residential mortgage-backed securities and collateralized mortgage obligations, term	14 years		14 years
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Proceeds from Sale of Available-for-sale Securities, Debt	$ 0
U.S. Government Sponsored Entities Asset-Backed Securities [Member] | Maximum [Member]
Schedule of Investments [Line Items]
Residential mortgage-backed securities and collateralized mortgage obligations, term	15 years		15 years