Fair Value Measurement - Financial Instruments Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Assets:
Fixed-maturity securities, available-for-sale:	$ 7,119	$ 8,202
Fixed-maturity securities, trading, at fair value	303	0
Short-term investments	810	1,225
Other invested assets	133	181
FG VIEs’ assets	413	260
Other assets	148	132
Liabilities:
Credit derivative liabilities	163	156
Liabilities of CIVs	715	289
RMBS
Assets:
Fixed-maturity securities, available-for-sale:	340
CMBS
Assets:
Fixed-maturity securities, available-for-sale:	271
Fair Value Measured at Net Asset Value
Assets:
Other invested assets	23	19
Recurring
Assets:
Short-term investments	810
Other invested assets	7	12
Other assets	148	132
Total assets carried at fair value	14,031	14,727
Liabilities:
Credit derivative liabilities	163	156
Liabilities of CIVs		289
Other liabilities	7	1
Total liabilities carried at fair value	5,316	4,295
Recurring | Financial Guaranty Variable Interest Entities
Liabilities:
Liabilities of CIVs	715
Recurring | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	4,431	3,849
Recurring | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	5,231	4,896
Recurring | Financial Guaranty Variable Interest Entities
Assets:
FG VIEs’ assets	413	260
Recurring | CLO obligations of CFEs | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	4,090	3,665
Recurring | Warehouse financing debt | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	313	126
Recurring | Securities sold short, at fair value | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs		41
Recurring | Borrowings | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	28	17
Recurring | Level 1
Assets:
Short-term investments	771
Other invested assets	2	6
Other assets	54	53
Total assets carried at fair value	962	1,429
Liabilities:
Credit derivative liabilities	0	0
Liabilities of CIVs		0
Other liabilities	0	0
Total liabilities carried at fair value	0	0
Recurring | Level 1 | Financial Guaranty Variable Interest Entities
Liabilities:
Liabilities of CIVs	0
Recurring | Level 1 | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	0	0
Recurring | Level 1 | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	135	145
Recurring | Level 1 | Financial Guaranty Variable Interest Entities
Assets:
FG VIEs’ assets	0	0
Recurring | Level 1 | CLO obligations of CFEs | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	0	0
Recurring | Level 1 | Warehouse financing debt | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	0	0
Recurring | Level 1 | Securities sold short, at fair value | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs		0
Recurring | Level 1 | Borrowings | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	0	0
Recurring | Level 2
Assets:
Short-term investments	39
Other invested assets	0	0
Other assets	46	54
Total assets carried at fair value	11,353	11,526
Liabilities:
Credit derivative liabilities	0	0
Liabilities of CIVs		0
Other liabilities	7	1
Total liabilities carried at fair value	284	145
Recurring | Level 2 | Financial Guaranty Variable Interest Entities
Liabilities:
Liabilities of CIVs	0
Recurring | Level 2 | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	277	144
Recurring | Level 2 | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	4,657	4,421
Recurring | Level 2 | Financial Guaranty Variable Interest Entities
Assets:
FG VIEs’ assets	209	0
Recurring | Level 2 | CLO obligations of CFEs | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	0	0
Recurring | Level 2 | Warehouse financing debt | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	277	103
Recurring | Level 2 | Securities sold short, at fair value | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs		41
Recurring | Level 2 | Borrowings | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	0	0
Recurring | Level 3
Assets:
Short-term investments	0
Other invested assets	5	6
Other assets	48	25
Total assets carried at fair value	1,716	1,772
Liabilities:
Credit derivative liabilities	163	156
Liabilities of CIVs		289
Other liabilities	0	0
Total liabilities carried at fair value	5,032	4,150
Recurring | Level 3 | Financial Guaranty Variable Interest Entities
Liabilities:
Liabilities of CIVs	715
Recurring | Level 3 | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	4,154	3,705
Recurring | Level 3 | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	439	330
Recurring | Level 3 | Financial Guaranty Variable Interest Entities
Assets:
FG VIEs’ assets	204	260
Recurring | Level 3 | CLO obligations of CFEs | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	4,090	3,665
Recurring | Level 3 | Warehouse financing debt | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	36	23
Recurring | Level 3 | Securities sold short, at fair value | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs		0
Recurring | Level 3 | Borrowings | Consolidated Investment Vehicles
Liabilities:
Liabilities of CIVs	28	17
Fixed-maturity securities
Assets:
Fixed-maturity securities, available-for-sale:	7,119	8,202
Fixed-maturity securities | Obligations of state and political subdivisions
Assets:
Fixed-maturity securities, available-for-sale:	3,394	3,660
Fixed-maturity securities | U.S. government and agencies
Assets:
Fixed-maturity securities, available-for-sale:	111	128
Fixed-maturity securities | Corporate securities
Assets:
Fixed-maturity securities, available-for-sale:	2,084	2,605
Fixed-maturity securities | RMBS
Assets:
Fixed-maturity securities, available-for-sale:	340	437
Fixed-maturity securities | CMBS
Assets:
Fixed-maturity securities, available-for-sale:	271	346
Fixed-maturity securities | Non-U.S. government securities
Assets:
Fixed-maturity securities, available-for-sale:	98	136
Fixed-maturity securities | Recurring
Assets:
Fixed-maturity securities, available-for-sale:	7,119	8,202
Fixed-maturity securities, trading, at fair value	303
Fixed-maturity securities | Recurring | Obligations of state and political subdivisions
Assets:
Fixed-maturity securities, available-for-sale:	3,394	3,660
Fixed-maturity securities | Recurring | U.S. government and agencies
Assets:
Fixed-maturity securities, available-for-sale:	111	128
Fixed-maturity securities | Recurring | Corporate securities
Assets:
Fixed-maturity securities, available-for-sale:	2,084	2,605
Fixed-maturity securities | Recurring | RMBS
Assets:
Fixed-maturity securities, available-for-sale:	340	437
Fixed-maturity securities | Recurring | CMBS
Assets:
Fixed-maturity securities, available-for-sale:	271	346
Fixed-maturity securities | Recurring | Asset-backed securities
Assets:
Fixed-maturity securities, available-for-sale:	821	890
Fixed-maturity securities | Recurring | Non-U.S. government securities
Assets:
Fixed-maturity securities, available-for-sale:	98	136
Fixed-maturity securities | Recurring | Level 1
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities, trading, at fair value	0
Fixed-maturity securities | Recurring | Level 1 | Obligations of state and political subdivisions
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 1 | U.S. government and agencies
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 1 | Corporate securities
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 1 | RMBS
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 1 | CMBS
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 1 | Asset-backed securities
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 1 | Non-U.S. government securities
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 2
Assets:
Fixed-maturity securities, available-for-sale:	6,099	7,051
Fixed-maturity securities, trading, at fair value	303
Fixed-maturity securities | Recurring | Level 2 | Obligations of state and political subdivisions
Assets:
Fixed-maturity securities, available-for-sale:	3,347	3,588
Fixed-maturity securities | Recurring | Level 2 | U.S. government and agencies
Assets:
Fixed-maturity securities, available-for-sale:	111	128
Fixed-maturity securities | Recurring | Level 2 | Corporate securities
Assets:
Fixed-maturity securities, available-for-sale:	2,084	2,605
Fixed-maturity securities | Recurring | Level 2 | RMBS
Assets:
Fixed-maturity securities, available-for-sale:	161	221
Fixed-maturity securities | Recurring | Level 2 | CMBS
Assets:
Fixed-maturity securities, available-for-sale:	271	346
Fixed-maturity securities | Recurring | Level 2 | Asset-backed securities
Assets:
Fixed-maturity securities, available-for-sale:	27	27
Fixed-maturity securities | Recurring | Level 2 | Non-U.S. government securities
Assets:
Fixed-maturity securities, available-for-sale:	98	136
Fixed-maturity securities | Recurring | Level 3
Assets:
Fixed-maturity securities, available-for-sale:	1,020	1,151
Fixed-maturity securities, trading, at fair value	0
Fixed-maturity securities | Recurring | Level 3 | Obligations of state and political subdivisions
Assets:
Fixed-maturity securities, available-for-sale:	47	72
Fixed-maturity securities | Recurring | Level 3 | U.S. government and agencies
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 3 | Corporate securities
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 3 | RMBS
Assets:
Fixed-maturity securities, available-for-sale:	179	216
Fixed-maturity securities | Recurring | Level 3 | CMBS
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Fixed-maturity securities | Recurring | Level 3 | Asset-backed securities
Assets:
Fixed-maturity securities, available-for-sale:	794	863
Fixed-maturity securities | Recurring | Level 3 | Non-U.S. government securities
Assets:
Fixed-maturity securities, available-for-sale:	0	0
Short-term investments | Recurring
Assets:
Fixed-maturity securities, available-for-sale:		1,225
Short-term investments | Recurring | Level 1
Assets:
Fixed-maturity securities, available-for-sale:		1,225
Short-term investments | Recurring | Level 2
Assets:
Fixed-maturity securities, available-for-sale:		0
Short-term investments | Recurring | Level 3
Assets:
Fixed-maturity securities, available-for-sale:		0
Fund Investments | Fair Value Measured at Net Asset Value | Equity securities and warrants | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	5	6
Fund Investments | Recurring | Obligations of state and political subdivisions | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets		101
Fund Investments | Recurring | Corporate securities | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	96	98
Fund Investments | Recurring | Equity securities and warrants | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	302	246
Fund Investments | Recurring | Structured products | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	128	62
Fund Investments | Recurring | Level 1 | Obligations of state and political subdivisions | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets		0
Fund Investments | Recurring | Level 1 | Corporate securities | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	0
Fund Investments | Recurring | Level 1 | Equity securities and warrants | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	0
Fund Investments | Recurring | Level 1 | Structured products | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	0
Fund Investments | Recurring | Level 2 | Obligations of state and political subdivisions | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets		101
Fund Investments | Recurring | Level 2 | Corporate securities | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	7
Fund Investments | Recurring | Level 2 | Equity securities and warrants | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	5	7
Fund Investments | Recurring | Level 2 | Structured products | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	82	62
Fund Investments | Recurring | Level 3 | Obligations of state and political subdivisions | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets		0
Fund Investments | Recurring | Level 3 | Corporate securities | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	96	91
Fund Investments | Recurring | Level 3 | Equity securities and warrants | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	297	239
Fund Investments | Recurring | Level 3 | Structured products | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	46	0
CLOs | Recurring | Short-term investments | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	135	145
CLOs | Recurring | Loans | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	4,570	4,244
CLOs | Recurring | Level 1 | Short-term investments | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	135	145
CLOs | Recurring | Level 1 | Loans | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	0
CLOs | Recurring | Level 2 | Short-term investments | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	0
CLOs | Recurring | Level 2 | Loans | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	4,570	4,244
CLOs | Recurring | Level 3 | Short-term investments | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	0
CLOs | Recurring | Level 3 | Loans | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	0	$ 0
Municipal Relative Fund Member | Fair Value Measured at Net Asset Value | Equity Securities And Warrants | Consolidated Investment Vehicles
Assets:
FG VIEs’ assets	$ 127