Derivative Financial Instruments (Detail) (Nondesignated, USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Derivatives, Fair Value [Line Items]
Notional Amount	$ 2,978,050
Treasury Options
Derivatives, Fair Value [Line Items]
Notional Amount	225,000
Forward commitments to sell loans/mortgage-backed securities
Derivatives, Fair Value [Line Items]
Notional Amount	1,406,940
Forward commitments to buy loans/mortgage-backed securities
Derivatives, Fair Value [Line Items]
Notional Amount	630,000
Interest rate lock commitments
Derivatives, Fair Value [Line Items]
Notional Amount	716,110
Other Asset
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	50,712	[1]
Other Asset | Treasury Options
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	131	[1]
Other Asset | Forward commitments to sell loans/mortgage-backed securities
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	50,581	[1]
Other Liability
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	32,744	[1]
Other Liability | Treasury Options
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	767	[1]
Other Liability | Forward commitments to sell loans/mortgage-backed securities
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	702	[1]
Other Liability | Forward commitments to buy loans/mortgage-backed securities
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	24,622	[1]
Other Liability | Interest rate lock commitments
Derivatives, Fair Value [Line Items]
Unrealized Gain (Loss)	$ 6,653	[1]

[1] Derivatives in a net gain position are recorded as "other assets" and derivatives in a net loss position are recorded as "other liabilities" in the Consolidated Statements of Condition.