Investments (Schedule Of Amortized Cost And Fair Value Of HTM Fixed Maturities And Related OTTI Recognized In Accumulated Other Comprehensive Income) (Detail) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	$ 9,566		$ 10,153
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(34)	$ (34)	(35)	$ (37)	$ (43)	$ (44)
Debt securities, held to maturity, net carrying value	9,532		10,118
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	18		533
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(217)		(4)
Held to maturity, at Fair Value	9,333		10,647
U.S. Treasury / Agency
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	1,298		1,213
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0		0
Debt securities, held to maturity, net carrying value	1,298		1,213
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	4		34
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(29)		(3)
Held to maturity, at Fair Value	1,273		1,244
Non-U.S.
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	1,112		1,201
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(4)		(5)
Debt securities, held to maturity, net carrying value	1,108		1,196
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	2		66
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(39)		0
Held to maturity, at Fair Value	1,071		1,262
Corporate and asset-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	1,844		2,032
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(28)		(28)
Debt securities, held to maturity, net carrying value	1,816		2,004
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	3		197
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(73)		0
Held to maturity, at Fair Value	1,746		2,201
Mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	1,651		1,731
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(1)		(1)
Debt securities, held to maturity, net carrying value	1,650		1,730
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	1		74
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(53)		(1)
Held to maturity, at Fair Value	1,598		1,803
Municipal
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	3,661		3,976
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(1)		(1)
Debt securities, held to maturity, net carrying value	3,660		3,975
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	8		162
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(23)		0
Held to maturity, at Fair Value	$ 3,645		$ 4,137