Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jan. 01, 2017
Income Taxes [Line Items]
Unrecognized tax benefits					$ 1
Impact of unrecognized tax benefits if recognized					$ 1
Period of expiration of the statute of limitations for certain jurisdictions			Within the next twelve months
Jurisdictions statutes of limitations expiration period			12 months
ASU 2016-09
Income Taxes [Line Items]
Excess tax benefit from share based compensation	$ 1	$ 24	$ 8	$ 35
Minimum
Income Taxes [Line Items]
Foreign and U.S. state and local jurisdictions have statutes of limitations, in years			3 years
Maximum
Income Taxes [Line Items]
Accrued interest and penalties	$ 1		$ 1
Foreign and U.S. state and local jurisdictions have statutes of limitations, in years			4 years