Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Examination [Line Items]
Gross deferred tax asset related to net operating loss carryforwards	$ 3,852	$ 3,010
Gross deferred tax asset related to foreign net operating loss carryforwards	$ 2,245
Year in which foreign net operating loss carryforwards begin to expire	2025
Gross deferred tax asset related to net U.S. federal operating loss carryforwards	$ 1,394
Year in which U.S. federal net operating loss carryforwards begin to expire	2020
Gross deferred tax asset related to net operating loss carryforwards for various U.S. states	$ 213
Year in which various U.S. states net operating loss carryforwards begin to expire	2016
Deferred tax asset related to foreign net operating loss carryforwards, net of valuation allowance	$ 1,631
Deferred tax asset related to federal net operating loss carryforwards, net of valuation allowance	1,394
Deferred tax asset related to state net operating loss carryforwards, net of valuation allowance	63
Alternative minimum tax credit carryforwards	102
Other business credit carryforwards	1
Deferred tax asset related to business credit carryforwards, net of valuation allowance	54
Foreign tax credit carryforwards - Before valuation allowance	$ 85
Year in which foreign tax credit carryforwards begin to expire	2016
Unrecognized tax benefits that would impact effective income tax rate	$ 529
Unrecognized tax benefits - Amounts due to lapses in statutes of limitation	4	0
Accrued interest and penalties	74	$ 62
Undistributed earnings from foreign subsidiaries expected to be indefinitely reinvested in foreign operations	7,700
Minimum
Income Tax Examination [Line Items]
Unrecognized tax benefits - Amounts due to lapses in statutes of limitation	109
Maximum
Income Tax Examination [Line Items]
Unrecognized tax benefits - Amounts due to lapses in statutes of limitation	$ 161