Investments - Concentration of Equity (Details) - Stockholders' Equity, Total - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
AT&T Inc.
Concentration Risk [Line Items]
Investments	$ 1,461
Wheels Donlen
Concentration Risk [Line Items]
Investments	1,454	$ 1,288
PK AirFinance
Concentration Risk [Line Items]
Investments	1,410	999
Athora
Concentration Risk [Line Items]
Investments	1,282	1,232
Atlas
Concentration Risk [Line Items]
Investments	1,007
Atlas – reverse repurchase agreement
Concentration Risk [Line Items]
Investments	922
AP Tundra
Concentration Risk [Line Items]
Investments	865	896
MFI Investments
Concentration Risk [Line Items]
Investments	$ 1,361	878
SoftBank Vision Fund II
Concentration Risk [Line Items]
Investments		789
MidCap
Concentration Risk [Line Items]
Investments		788
Cayman Universe
Concentration Risk [Line Items]
Investments		$ 756