Commitments and Contingencies (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013 properties	Sep. 30, 2012	Sep. 30, 2013 loan properties	Sep. 30, 2012	Dec. 31, 2012
Loss Contingencies [Line Items]
RecoveriesInConnectionWithStandbyLettersOfCredit	$ (116,000)
Litigation settlement other company owned stock	4,400,000,000		4,400,000,000
Number of non-cancelable operating leases	159		159
Rent expense	4,900,000	4,200,000	14,200,000	12,800,000
Rent income	148,000	248,000	596,000	856,000
Losses in connection with standby letters of credit	0	0	78,000	0
Standby letters of credit that expire thereafter	18,300,000		18,300,000
Standby letters of credit that expire within one year	31,100,000		31,100,000
Fair value of guarantee with standby letters of credit	206,000		206,000
Number of loans repurchased due to deficiencies in underwriting or loan documentation			20
Concentration risk, percentage			75.00%		79.00%
Visa Inc [Member]
Loss Contingencies [Line Items]
Other company stock owned shares	468,659		468,659
Conversion ratio from Class B shares into Class A shares			42.06%
Value of the Class A shares	$ 191.1		$ 191.1
Unredeemed Class A equivalent shares owned			$ 37,700,000