Fair Value Measurement (Changes In Fair Value Included In The Company's Consolidated Statements Of Operations) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Loan Repurchase Commitments [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 44	$ 39	$ 43	$ 70
Fixed-Maturity Securities Held At Fair Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	(56)	(265)	(57)	(52)
Residential Mortgage Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	(117)	29	(99)	130
Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	(2)	(35)	(41)	7
Other Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange		18		(22)
Long-term Debt [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 135	$ 252	$ 128	$ (115)