Investments - Realized capital gains and losses by asset type (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Realized capital gains and losses by asset type
Net gains (losses) on investments and derivatives	$ (1,072)	$ 1,084	$ 1,087
Net gains (losses) on investments and derivatives
Realized capital gains and losses by asset type
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives
Fair Value, Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives	Net gains (losses) on investments and derivatives
Fixed income securities
Realized capital gains and losses by asset type
Net gains (losses) on investments and derivatives	$ (875)	$ 425	$ 925
Equity securities
Realized capital gains and losses by asset type
Net gains (losses) on investments and derivatives	(900)	520	117
Mortgage loans
Realized capital gains and losses by asset type
Net gains (losses) on investments and derivatives	(1)	20	(1)
Limited partnership interests
Realized capital gains and losses by asset type
Net gains (losses) on investments and derivatives	(191)	(52)	(14)
Derivatives
Realized capital gains and losses by asset type
Net gains (losses) on investments and derivatives	874	49	49
Other investments
Realized capital gains and losses by asset type
Net gains (losses) on investments and derivatives	$ 21	$ 122	$ 11