Operating Leases, Commitments and Contingencies, and Guarantees (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 12, 2016
Guarantee Obligations [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 2,000
Indemnification Agreement [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	260
Guarantee agreement [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	375
Guarantee and Indemnification [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Current Carrying Value	5	$ 5
Property Subject to Operating Lease [Member]
Loss Contingencies [Line Items]
Operating Leases, Rent Expense	46	55	$ 46
Property Lease Guarantee [Member]
Loss Contingencies [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 20
Sublease [Member]
Loss Contingencies [Line Items]
Operating Leases, Income Statement, Sublease Revenue		$ 1	$ 3
Subsequent Event [Member]
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months				$ 9
Operating Leases, Future Minimum Payments, Due in Two Years				10
Operating Leases, Future Minimum Payments, Due in Three Years				4
Operating Leases, Future Minimum Payments, Due in Four Years				0
Operating Leases, Future Minimum Payments, Due in Five Years				5
Operating Leases, Future Minimum Payments, Due Thereafter				$ 138