Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Provision (benefit) for income taxes	$ 1,378	$ 1,261	$ 1,108
Excess tax benefits		222	150
Provision for income taxes	51
Reductions in interest (net of tax) related to taxing authority examinations	15	7	6
Foreign pretax income	149	178	$ 238
State net operating loss carryforwards	103
Federal net operating loss carryforwards	94
Liability for unrecognized tax benefits	418	554
Unrecognized tax benefits, accrued interest	45	73
Unrecognized tax benefits that would impact effective tax rate	137	233
Deferred tax assets, reductions	$ 4	$ 6
State and Local Jurisdiction [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration date	2019
State and Local Jurisdiction [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration date	2035
Accounting Standards Update 2016-09 [Member]
Income Tax Contingency [Line Items]
Provision (benefit) for income taxes	$ 162