Investment Securities (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule of Investments [Line Items]
Investment Securities average remaining life			5 years 2 months
Available-for-sale Securities and Held-to-maturity Securities	0	0	0	468
Other than Temporary Impairment Losses, Investments	$ 0		$ 0	$ 0
Asset backed securities mortgage portfolio, term			15 years
Gain (Loss) on Sale of Investments				$ 20,000
U.S. Treasury And Sponsored Entities Callable Notes [Member]
Schedule of Investments [Line Items]
Available for Sale expected to be called	150,300,000		$ 150,300,000
Available-for-sale securities	$ 545,100,000		$ 545,100,000
U.S. Treasury And Sponsored Entities Callable Notes [Member] | Minimum [Member]
Schedule of Investments [Line Items]
Available for Sale Securities, Debt Maturities, Term			2 years
U.S. Treasury And Sponsored Entities Callable Notes [Member] | Maximum [Member]
Schedule of Investments [Line Items]
Available for Sale Securities, Debt Maturities, Term			7 years