Equity (Balance of and Changes in Each Component of AOCI) (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ 5,359	$ 3,137
Other comprehensive income (loss) before reclassifications		(1,555)	906
Amounts reclassified to (from) AOCI		(151)	2
Deferred income tax benefit (expense)		388	(244)
Accumulated Other Comprehensive Income (Loss), Net of Tax		4,041	3,801
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax		(69)	(92)
Other comprehensive income (loss) before reclassifications		55	(116)
Amounts reclassified to (from) AOCI		0	0
Deferred income tax benefit (expense)		6	2
Accumulated Other Comprehensive Income (Loss), Net of Tax		(20)	(210)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	5,500	3,299
Other comprehensive income (loss) before reclassifications	[1]	(1,607)	1,034
Amounts reclassified to (from) AOCI	[1]	(154)	0
Deferred income tax benefit (expense)	[1]	394	(244)
Accumulated Other Comprehensive Income (Loss), Net of Tax	[1]	4,133	4,089
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax		(72)	(70)
Other comprehensive income (loss) before reclassifications		(3)	(12)
Amounts reclassified to (from) AOCI		3	2
Deferred income tax benefit (expense)		0	2
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (72)	$ (78)

[1] Includes cash flow hedges of $(40) and $(49) as of June 30, 2021 and December 31, 2020, respectively, and $(74) and $(26) as of June 30, 2020 and December 31, 2019, respectively. See Note 5 – “Derivative Instruments” for additional information on cash flow hedges.