Guarantees - Additional Information (Detail) (USD $)													3 Months Ended			3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Mar. 31, 2012 Parent Company [Member] Debt Securities Payable Member	Dec. 31, 2011 Parent Company [Member] Debt Securities Payable Member	Mar. 31, 2011 Parent Company [Member] Debt Securities Payable Member	Mar. 31, 2012 Loans With Recourse [Member]	Dec. 31, 2011 Loans With Recourse [Member]	Mar. 31, 2011 Loans With Recourse [Member]	Mar. 31, 2012 Serviced Mortgage Loans [Member]	Dec. 31, 2011 Serviced Mortgage Loans [Member]	Mar. 31, 2011 Serviced Mortgage Loans [Member]	Mar. 31, 2012 Serviced Mortgage Loans [Member] Loans With Recourse [Member]	Mar. 31, 2011 Serviced Mortgage Loans [Member] Loans With Recourse [Member]	Dec. 31, 2011 Serviced Mortgage Loans [Member] Loans With Recourse [Member]	Mar. 31, 2012 Serviced Mortgage Loans [Member] Puerto Rico Banking Subsidiaries Loans Serviced Under Representation Warranties [Member]	Mar. 31, 2011 Serviced Mortgage Loans [Member] Puerto Rico Banking Subsidiaries Loans Serviced Under Representation Warranties [Member]	Mar. 31, 2012 Serviced Mortgage Loans For Which Loan Originator Discharged From Repurchae Obligation And Claim [Member]	Mar. 31, 2011 Serviced Mortgage Loans For Which Loan Originator Discharged From Repurchae Obligation And Claim [Member]	Mar. 31, 2012 Financial Standby Letter Of Credit Member	Dec. 31, 2011 Financial Standby Letter Of Credit Member	Mar. 31, 2011 Financial Standby Letter Of Credit Member	Mar. 31, 2012 Indemnification Guarantee Member E Loan [Member]	Dec. 31, 2011 Indemnification Guarantee Member E Loan [Member]	Mar. 31, 2011 Indemnification Guarantee Member E Loan [Member]	Dec. 31, 2010 Indemnification Guarantee Member E Loan [Member]	Mar. 31, 2012 Guarantee Type, Other [Member] Parent Company [Member] Underlying Other Member	Dec. 31, 2011 Guarantee Type, Other [Member] Parent Company [Member] Underlying Other Member	Mar. 31, 2011 Guarantee Type, Other [Member] Parent Company [Member] Underlying Other Member
Guarantor Obligations [Line Items]
Guarantees, unamortized balance of the obligations				$ 600,000,000	$ 700,000,000	$ 700,000,000														$ 1,000,000	$ 500,000	$ 600,000					$ 1,400,000,000	$ 1,400,000,000	$ 1,400,000,000
Unpaid Principal Balance F D I C Agreement																		3,400,000,000	3,500,000,000
Repurchased Loans													50,000,000	63,000,000		400,000	4,800,000
Valuation Allowances And Reserves Balance													56,000,000	55,000,000	59,000,000			8,600,000	8,500,000				10,625,000	10,625,000	30,688,000	30,659,000
Funds Advanced To Investors Under Servicing Agreements	34,000,000	32,000,000	28,000,000
Qualitative And Quantitative Information Assets Or Liabilities For Transferors Continuing Involvement In Securitization Or Assetbacked Financing Arrangement Principal Amounts Outstanding							3,300,000,000	3,500,000,000	3,800,000,000	17,200,000,000	17,300,000,000	18,000,000,000
Losses Recorded From Reps Warrants Repurchases																$ 100,000	$ 400,000