Investments in fixed maturity securities (Tables)

12 Months Ended

Dec. 31, 2023

Investments, Debt and Equity Securities [Abstract]

Schedule of investments in securities with fixed maturities

Investments in fixed maturity securities are summarized by type below (in millions).

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
December 31, 2023
U.S. Treasury, U.S. government corporations and agencies	$	10,308	$	14	$	(53	)	$	10,269
Foreign governments		11,788		58		(41	)		11,805
Corporate bonds		1,212		241		(4	)		1,449
Other		217		21		(3	)		235
	$	23,525	$	334	$	(101	)	$	23,758
December 31, 2022
U.S. Treasury, U.S. government corporations and agencies	$	10,039	$	12	$	(249	)	$	9,802
Foreign governments		10,454		50		(177	)		10,327
Corporate bonds		1,945		256		(6	)		2,195
Other		2,735		77		(8	)		2,804
	$	25,173	$	395	$	(440	)	$	25,128

Schedule of amortized cost and estimated fair value of securities with fixed maturities

The amortized cost and estimated fair value of fixed maturity securities at December 31, 2023 are summarized below by contractual maturity dates (in millions). Actual maturities may differ from contractual maturities due to prepayment rights held by issuers.

	Due in one year or less		Due after one year through five years		Due after five years through ten years		Due after ten years		Mortgage-backed securities		Total
Amortized cost	$	18,888	$	3,744	$	611	$	128	$	154	$	23,525
Fair value		18,875		3,754		823		138		168		23,758