Operating Leases (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Leases, Operating [Abstract]
Operating Leases, Rent Expense	$ 60	$ 46	$ 55
Operating Leases, Income Statement, Sublease Revenue			$ 1
Minimum Lease Payments, Sale Leaseback Transactions, Next Twelve Months	10
Minimum Lease Payments, Sale Leaseback Transactions, within Two Years	$ 4