Business Developments, Risks And Uncertainties, And Liquidity (Change In Credit Spreads (Asset/Liability Products Business) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012
200 Basis Point Decrease [Member]
Business Acquisition [Line Items]
Estimated change in fair value	$ 174
50 Basis Point Decrease [Member]
Business Acquisition [Line Items]
Estimated change in fair value	54
50 Basis Point Increase [Member]
Business Acquisition [Line Items]
Estimated change in fair value	(49)
200 Basis Point Increase [Member]
Business Acquisition [Line Items]
Estimated change in fair value	$ (173)