Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax [Line Items]
Undistributed earnings of foreign subsidiaries	$ 6,000
Undistributed foreign earnings	5
Unremitted earnings	6,000
Operating loss carryforwards	1,400
Operating loss carryforwards, not subject to expiration	982
Operating loss carryforwards, subject to expiration	434
Valuation allowance	213	$ 271
Valuation allowance, deferred tax asset, change in amount		53
Unrecognized tax benefits that would impact effective tax rate	387	437	$ 444
Unrecognized tax benefits, income tax penalties and interest expense	5	11	$ 8
Decrease in unrecognized tax benefits	4
Minimum
Income Tax [Line Items]
Potential income tax expense due to change in tax regulation	180
Maximum
Income Tax [Line Items]
Potential income tax expense due to change in tax regulation	220
Operations Deferred Tax Asset Deemed Realizable
Income Tax [Line Items]
Valuation allowance	213	271
Valuation allowance, deferred tax asset, change in amount	(58)	$ 76
Domestic Tax Authority
Income Tax [Line Items]
Operating loss carryforwards	249
Operating loss carryforwards, subject to expiration, varying limitations	102
Operating loss carryforwards excluded from statement of financial condition	98
Operating loss carryforwards utilized in the current year	32
Domestic Tax Authority | Carryback 3 years, carryforward 5 years
Income Tax [Line Items]
Operating loss carryforwards, not subject to expiration	755
Domestic Tax Authority | Tax year 2018
Income Tax [Line Items]
Operating loss carryforwards, not subject to expiration	313
Domestic Tax Authority | Tax year 2020
Income Tax [Line Items]
Operating loss carryforwards, not subject to expiration	442
Foreign Tax Authority
Income Tax [Line Items]
Operating loss carryforwards	1,200
State Jurisdiction
Income Tax [Line Items]
Operating loss carryforwards	292
Operating loss carryforwards, subject to expiration	1,000
Operating loss carryforwards, subject to expiration, varying limitations	38
Operating loss carryforwards excluded from statement of financial condition	38
Operating loss carryforwards utilized in the current year	6
State Jurisdiction | Carryback 3 years, carryforward 5 years
Income Tax [Line Items]
Operating loss carryforwards	183
State Jurisdiction | Tax year 2018
Income Tax [Line Items]
Operating loss carryforwards	136
State Jurisdiction | Tax year 2020
Income Tax [Line Items]
Operating loss carryforwards	156
State Jurisdiction | Five-year carryforward
Income Tax [Line Items]
Operating loss carryforwards	$ 109