Significant Unobservable Inputs used in Fair Value Measurement (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Capital trust notes
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	$ 17,375
Valuation Technique	Discounted Cash Flow
Weighted Average Discount Rate	5.40%	[1]
Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	122,240		116,416	95,014	106,186
Valuation Technique	Discounted Cash Flow
Weighted Average Constant Prepayment Rate	17.70%	[2]
Weighted Average Discount Rate	10.50%
Interest Rate Lock Commitments
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	$ 56,079
Valuation Technique	Pricing Model
Weighted Average Closing Ratio	74.58%

[1] Derived from multiple interest rate scenarios that incorporate a spread to the London Interbank Offered Rate swap curve and market volatility.

[2] Represents annualized loan repayment rate assumptions.