Investments - Investment Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Schedule of Investments
Securities sold, not yet purchased, at fair value	$ 1,000		$ 1,000		$ 1,382
Investment Segment
Schedule of Investments
Securities sold, not yet purchased, at fair value	1,000		1,000		1,382
Portion of unrealized gains and (losses) that relates to equity and debt securities still held	149	$ 11	91	$ (204)
Investment Segment \| Equity securities
Schedule of Investments
Equity securities	1,388		1,388		2,146
Investment Segment \| Communications
Schedule of Investments
Equity securities	142		142		371
Investment Segment \| Consumer, cyclical
Schedule of Investments
Equity securities	161		161		180
Investment Segment \| Energy
Schedule of Investments
Equity securities	69		69		71
Securities sold, not yet purchased, at fair value	882		882		798
Investment Segment \| Utilities
Schedule of Investments
Equity securities	59		59		622
Securities sold, not yet purchased, at fair value	51		51		525
Investment Segment \| Healthcare
Schedule of Investments
Equity securities	58		58		99
Investment Segment \| Technology
Schedule of Investments
Equity securities	8		8
Investment Segment \| Materials
Schedule of Investments
Equity securities	339		339		288
Investment Segment \| Industrial
Schedule of Investments
Equity securities	552		552		515
Securities sold, not yet purchased, at fair value	$ 67		$ 67		$ 59