Assets by Class of Instrument that are Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions		Jun. 30, 2020		Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		$ 63,544		$ 60,339
Available-for-sale equity securities		206		239
Derivative assets, fair value		1,062		310
Total other invested assets		2,473		1,632
Separate account assets		5,536		6,108
Total assets		71,195		67,761
Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Available-for-sale equity securities	[1]	0		0
Separate account assets	[1]	0		0
Total assets	[1]	598		503
Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		1,024		290
Securities lending collateral		59		51
Short-term investments		190		211
Limited partnerships		598		503
Total other invested assets		1,871		1,055
Other invested assets | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[1]	0		0
Securities lending collateral	[1]	0		0
Short-term investments	[1]	0		0
Limited partnerships	[1]	598		503
Total other invested assets	[1]	598		503
Interest rate swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		939		197
Interest rate swaps | Other invested assets | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[1]	0		0
Foreign currency swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		17		4
Foreign currency swaps | Other invested assets | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[1]	0		0
Equity index options | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		66		81
Equity index options | Other invested assets | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[1]	0		0
Other foreign currency contracts | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		2		8
Other foreign currency contracts | Other invested assets | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[1]	0		0
GMWB embedded derivatives | Reinsurance recoverable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[2]	38		20
GMWB embedded derivatives | Reinsurance recoverable | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[1],[2]	0		0
Fixed maturity securities | U.S. government, agencies and government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		5,602		5,025
Fixed maturity securities | U.S. government, agencies and government-sponsored enterprises | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | State and Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,998		2,747
Fixed maturity securities | State and Political Subdivisions | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,542		1,350
Fixed maturity securities | Non-U.S. government | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		34,395		32,111
Fixed maturity securities | U.S. corporate | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		5,270		4,997
Fixed maturity securities | U.S. corporate | Utilities | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,594		2,699
Fixed maturity securities | U.S. corporate | Energy | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		8,403		7,774
Fixed maturity securities | U.S. corporate | Finance and insurance | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		6,277		5,701
Fixed maturity securities | U.S. corporate | Consumer-non-cyclical | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		3,411		3,245
Fixed maturity securities | U.S. corporate | Technology and communications | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,503		1,396
Fixed maturity securities | U.S. corporate | Industrial | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		3,028		2,711
Fixed maturity securities | U.S. corporate | Capital goods | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,966		1,760
Fixed maturity securities | U.S. corporate | Consumer-cyclical | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,565		1,506
Fixed maturity securities | U.S. corporate | Transportation | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		378		322
Fixed maturity securities | U.S. corporate | Other | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		10,885		10,525
Fixed maturity securities | Non-U.S. corporate | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		879		829
Fixed maturity securities | Non-U.S. corporate | Utilities | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,275		1,319
Fixed maturity securities | Non-U.S. corporate | Energy | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,466		2,319
Fixed maturity securities | Non-U.S. corporate | Finance and insurance | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		777		684
Fixed maturity securities | Non-U.S. corporate | Consumer-non-cyclical | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,247		1,138
Fixed maturity securities | Non-U.S. corporate | Technology and communications | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		995		988
Fixed maturity securities | Non-U.S. corporate | Industrial | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		613		605
Fixed maturity securities | Non-U.S. corporate | Capital goods | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		407		397
Fixed maturity securities | Non-U.S. corporate | Consumer-cyclical | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		635		629
Fixed maturity securities | Non-U.S. corporate | Transportation | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Non-U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,591		1,617
Fixed maturity securities | Non-U.S. corporate | Other | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,184		2,270
Fixed maturity securities | Residential mortgage-backed | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,970		3,026
Fixed maturity securities | Commercial mortgage-backed | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Fixed maturity securities | Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,968		3,285
Fixed maturity securities | Other asset-backed | Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities	[1]	0		0
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Available-for-sale equity securities		45		62
Total other invested assets	[3]	0		0
Separate account assets		5,536		6,108
Total assets		5,581		6,170
Level 1 | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Securities lending collateral		0		0
Short-term investments		0		0
Limited partnerships		0		0
Total other invested assets		0		0
Level 1 | Interest rate swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 1 | Foreign currency swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 1 | Equity index options | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 1 | Other foreign currency contracts | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 1 | GMWB embedded derivatives | Reinsurance recoverable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[2]	0		0
Level 1 | Fixed maturity securities | U.S. government, agencies and government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | State and Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Non-U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 1 | Fixed maturity securities | Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		59,289		56,148
Available-for-sale equity securities		108		126
Total other invested assets	[3]	22		49
Separate account assets		0		0
Total assets		60,604		56,745
Level 2 | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		958		209
Securities lending collateral		59		51
Short-term investments		190		211
Limited partnerships		0		0
Total other invested assets		1,207		471
Level 2 | Interest rate swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		939		197
Level 2 | Foreign currency swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		17		4
Level 2 | Equity index options | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 2 | Other foreign currency contracts | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		2	[1]	8
Level 2 | GMWB embedded derivatives | Reinsurance recoverable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[2]	0		0
Level 2 | Fixed maturity securities | U.S. government, agencies and government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		5,602		5,025
Level 2 | Fixed maturity securities | State and Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,935		2,645
Level 2 | Fixed maturity securities | Non-U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,542		1,350
Level 2 | Fixed maturity securities | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		32,063		29,872
Level 2 | Fixed maturity securities | U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		4,334		4,132
Level 2 | Fixed maturity securities | U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,471		2,570
Level 2 | Fixed maturity securities | U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		7,852		7,202
Level 2 | Fixed maturity securities | U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		6,174		5,607
Level 2 | Fixed maturity securities | U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		3,345		3,195
Level 2 | Fixed maturity securities | U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,464		1,356
Level 2 | Fixed maturity securities | U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,931		2,609
Level 2 | Fixed maturity securities | U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,768		1,587
Level 2 | Fixed maturity securities | U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,511		1,428
Level 2 | Fixed maturity securities | U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		213		186
Level 2 | Fixed maturity securities | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		9,191		8,840
Level 2 | Fixed maturity securities | Non-U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		522		455
Level 2 | Fixed maturity securities | Non-U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,038		1,072
Level 2 | Fixed maturity securities | Non-U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,155		2,085
Level 2 | Fixed maturity securities | Non-U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		723		625
Level 2 | Fixed maturity securities | Non-U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,219		1,110
Level 2 | Fixed maturity securities | Non-U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		903		884
Level 2 | Fixed maturity securities | Non-U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		440		444
Level 2 | Fixed maturity securities | Non-U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		251		250
Level 2 | Fixed maturity securities | Non-U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		494		438
Level 2 | Fixed maturity securities | Non-U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,446		1,477
Level 2 | Fixed maturity securities | Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,160		2,243
Level 2 | Fixed maturity securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,949		3,020
Level 2 | Fixed maturity securities | Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,847		3,153
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		4,255		4,191
Available-for-sale equity securities		53		51
Total other invested assets	[3]	399		383
Separate account assets		0		0
Total assets		4,412		4,343
Level 3 | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		66		81
Securities lending collateral		0		0
Short-term investments		0		0
Limited partnerships		0		0
Total other invested assets		66		81
Level 3 | Interest rate swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 3 | Foreign currency swaps | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 3 | Equity index options | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		66		81
Level 3 | Other foreign currency contracts | Other invested assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value		0		0
Level 3 | GMWB embedded derivatives | Reinsurance recoverable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	[2]	38		20
Level 3 | Fixed maturity securities | U.S. government, agencies and government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 3 | Fixed maturity securities | State and Political Subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		63		102
Level 3 | Fixed maturity securities | Non-U.S. government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		0		0
Level 3 | Fixed maturity securities | U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		2,332		2,239
Level 3 | Fixed maturity securities | U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		936		865
Level 3 | Fixed maturity securities | U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		123		129
Level 3 | Fixed maturity securities | U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		551		572
Level 3 | Fixed maturity securities | U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		103		94
Level 3 | Fixed maturity securities | U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		66		50
Level 3 | Fixed maturity securities | U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		39		40
Level 3 | Fixed maturity securities | U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		97		102
Level 3 | Fixed maturity securities | U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		198		173
Level 3 | Fixed maturity securities | U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		54		78
Level 3 | Fixed maturity securities | U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		165		136
Level 3 | Fixed maturity securities | Non-U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		1,694		1,685
Level 3 | Fixed maturity securities | Non-U.S. corporate | Utilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		357		374
Level 3 | Fixed maturity securities | Non-U.S. corporate | Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		237		247
Level 3 | Fixed maturity securities | Non-U.S. corporate | Finance and insurance
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		311		234
Level 3 | Fixed maturity securities | Non-U.S. corporate | Consumer-non-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		54		59
Level 3 | Fixed maturity securities | Non-U.S. corporate | Technology and communications
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		28		28
Level 3 | Fixed maturity securities | Non-U.S. corporate | Industrial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		92		104
Level 3 | Fixed maturity securities | Non-U.S. corporate | Capital goods
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		173		161
Level 3 | Fixed maturity securities | Non-U.S. corporate | Consumer-cyclical
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		156		147
Level 3 | Fixed maturity securities | Non-U.S. corporate | Transportation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		141		191
Level 3 | Fixed maturity securities | Non-U.S. corporate | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		145		140
Level 3 | Fixed maturity securities | Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		24		27
Level 3 | Fixed maturity securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		21		6
Level 3 | Fixed maturity securities | Other asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale debt securities		$ 121		$ 132

[1] Limited partnerships that are measured at fair value using the NAV per share (or its equivalent) practical expedient have not been categorized in the fair value hierarchy.

[2] Represents embedded derivatives associated with the reinsured portion of our GMWB liabilities.

[3] These financial instruments do not have notional amounts.