Commitments Guarantees and Contingencies (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Loss Contingencies [Line Items]
Credit of Unfunded Commitments	$ 768,900,000	$ 256,900,000
Fixed Rate Unfunded Commitment	746,700,000	250,200,000
Adjustable Rate Unfunded Commitment	22,100,000	6,700,000
Loss Contingency, Loss in Period	2,800,000	826,000	373,000
Operating Leases, Rent Expense, Net	7,100,000	5,700,000	6,400,000
Loans serviced for others	9,651,041,000	7,700,605,000
Loss Contingency, Pending Claims, Number	0
Representations and Warranties Reserve for Loan Receivables [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	8,920,000,000	6,940,000,000
Loss Contingency Accrual, at Carrying Value	1,955,000	471,000	533,000
Loss Contingency Accrual, Carrying Value, Provision	4,317,000	764,000
Loss Contingency Accrual, Carrying Value, Payments	2,833,000	826,000
Legal Reserve [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, at Carrying Value	0
Home Equity and Business Banking Credit Lines [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	91,100,000	87,100,000
Undisbursed construction loan funds [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	34,500,000	9,700,000
Credit Risk [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, at Carrying Value	190,000	111,000	389,000
Multifamily Residential [Member] | Loss Sharing Relationship [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, at Carrying Value	3,300,000	3,600,000
Loss Contingency, Loss in Period	0
Loans serviced for others	$ 727,100,000	$ 758,500,000