Investments in fixed maturity securities (Tables)

12 Months Ended

Dec. 31, 2020

Investments Debt And Equity Securities [Abstract]

Schedule of investments in securities with fixed maturities

Investments in fixed maturity securities as of December 31, 2020 and 2019 are summarized by type below (in millions).

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
December 31, 2020
U.S. Treasury, U.S. government corporations and agencies	$	3,348	$	55	$	—		$	3,403
Foreign governments		11,233		110		(5	)		11,338
Corporate bonds		4,729		464		(2	)		5,191
Other		414		66		(2	)		478
	$	19,724	$	695	$	(9	)	$	20,410
December 31, 2019
U.S. Treasury, U.S. government corporations and agencies	$	3,054	$	37	$	(1	)	$	3,090
Foreign governments		8,584		63		(9	)		8,638
Corporate bonds		5,896		459		(3	)		6,352
Other		539		67		(1	)		605
	$	18,073	$	626	$	(14	)	$	18,685

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, 2020 are summarized below by contractual maturity dates. Amounts are in millions. Actual maturities may differ from contractual maturities due to early call or 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	$	10,379	$	8,323	$	373	$	337	$	312	$	19,724
Fair value		10,448		8,456		496		640		370		20,410