Fair Value Measurements - Carrying Values and Estimated Fair Values of our Financial Instruments not Measured at Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025
Assets:
Mortgage and other loans receivable	$ 2,813	$ 2,887
Other investments	7,015	6,696
Short-term investments	8,196	11,141
Cash	1,454	1,274	$ 1,393
Other assets	4,683	4,773
Liabilities:
Fortitude Re funds withheld payable	2,960	3,038
Consolidated Entity, Excluding Consolidated VIE
Liabilities:
Long-term debt	9,001	9,035
Consolidated VIE
Liabilities:
Long-term debt	155	156
Estimated Fair Value
Assets:
Mortgage and other loans receivable	2,750	2,834
Other investments	492	493
Short-term investments	3,319	5,232
Cash	1,454	1,274
Other assets	17	16
Liabilities:
Fortitude Re funds withheld payable	3,045	3,130
Estimated Fair Value | Consolidated Entity, Excluding Consolidated VIE
Liabilities:
Long-term debt	8,461	8,702
Estimated Fair Value | Consolidated VIE
Liabilities:
Long-term debt	155	156
Carrying Value
Assets:
Mortgage and other loans receivable	2,813	2,887
Other investments	492	493
Short-term investments	3,319	5,232
Cash	1,454	1,274
Other assets	17	16
Liabilities:
Fortitude Re funds withheld payable	3,045	3,130
Carrying Value | Consolidated Entity, Excluding Consolidated VIE
Liabilities:
Long-term debt	9,001	9,035
Carrying Value | Consolidated VIE
Liabilities:
Long-term debt	155	156
Level 1
Assets:
Short-term investments	3,253	4,106
Liabilities:
Fortitude Re funds withheld payable	0	0
Level 1 | Estimated Fair Value
Assets:
Mortgage and other loans receivable	0	0
Other investments	0	0
Short-term investments	0	0
Cash	1,454	1,274
Other assets	17	16
Liabilities:
Fortitude Re funds withheld payable	0	0
Level 1 | Estimated Fair Value | Consolidated Entity, Excluding Consolidated VIE
Liabilities:
Long-term debt	0	0
Level 1 | Estimated Fair Value | Consolidated VIE
Liabilities:
Long-term debt	0	0
Level 2
Assets:
Short-term investments	1,624	1,803
Liabilities:
Fortitude Re funds withheld payable	0	0
Level 2 | Estimated Fair Value
Assets:
Mortgage and other loans receivable	307	334
Other investments	480	480
Short-term investments	3,319	5,232
Cash	0	0
Other assets	0	0
Liabilities:
Fortitude Re funds withheld payable	0	0
Level 2 | Estimated Fair Value | Consolidated Entity, Excluding Consolidated VIE
Liabilities:
Long-term debt	8,461	8,702
Level 2 | Estimated Fair Value | Consolidated VIE
Liabilities:
Long-term debt	0	0
Level 3
Assets:
Short-term investments	0	0
Liabilities:
Fortitude Re funds withheld payable	85	92
Level 3 | Estimated Fair Value
Assets:
Mortgage and other loans receivable	2,443	2,500
Other investments	12	13
Short-term investments	0	0
Cash	0	0
Other assets	0	0
Liabilities:
Fortitude Re funds withheld payable	3,045	3,130
Level 3 | Estimated Fair Value | Consolidated Entity, Excluding Consolidated VIE
Liabilities:
Long-term debt	0	0
Level 3 | Estimated Fair Value | Consolidated VIE
Liabilities:
Long-term debt	$ 155	$ 156