Investment Securities (Other Disclosures) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
FHLB stock	$ 5,900,000		$ 5,900,000		$ 6,300,000
FRBR stock	4,100,000		4,100,000		3,100,000
Investment securities portfolio available as lendable collateral	394,100,000		394,100,000
Book value of securities sold	3,300,000	21,400,000	175,100,000	134,100,000
Gain on securities sold	50,000	(33,000)	2,773,000	1,923,000
Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities portfolio pledged as collateral	94,100,000		94,100,000
Retail repurchase agreements [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities portfolio pledged as collateral	18,400,000		18,400,000
Others [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities portfolio pledged as collateral	$ 78,900,000		$ 78,900,000