Total Equity and Other Comprehensive Income (Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pre-tax
Other comprehensive income (loss), before tax and net of reclassifications into Net income	$ 784	$ (548)	$ 351	$ 842
Tax effect
Total other comprehensive income (loss)	(188)	131	(85)	(195)
After-tax
Other comprehensive income (loss), after tax and net of reclassifications into Net income	596	(417)	266	647
Debt securities
Pre-tax
Net unrealized gains (losses)	(216)	(476)	(611)	178
Less: Net realized gains (losses) reclassified to earnings	(691)	(235)	(907)	(450)
Other comprehensive income (loss), before tax and net of reclassifications into Net income	475	(241)	296	628
Tax effect
Net unrealized gains (losses)	52	112	147	(42)
Less: Net realized gains (losses) reclassified to earnings	166	55	218	106
Total other comprehensive income (loss)	(114)	57	(71)	(148)
After-tax
Net unrealized gains (losses)	(164)	(364)	(464)	136
Less: Net realized gains (losses) reclassified to earnings	(525)	(180)	(689)	(344)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	361	(184)	225	480
Cash flow hedge derivatives
Pre-tax
Net unrealized gains (losses)	(75)	(689)	(701)	(492)
Less: Net realized gains (losses) reclassified to earnings	(383)	(373)	(759)	(703)
Other comprehensive income (loss), before tax and net of reclassifications into Net income	308	(316)	58	211
Tax effect
Net unrealized gains (losses)	18	162	168	116
Less: Net realized gains (losses) reclassified to earnings	92	88	182	166
Total other comprehensive income (loss)	(74)	74	(14)	(50)
After-tax
Net unrealized gains (losses)	(57)	(527)	(533)	(376)
Less: Net realized gains (losses) reclassified to earnings	(291)	(285)	(577)	(537)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	234	(242)	44	161
Pension and  other postretirement benefit plan adjustments
Pre-tax
Less: Net realized gains (losses) reclassified to earnings	1	6	(1)	(4)
Other comprehensive income (loss), before tax and net of reclassifications into Net income	1	6	(1)	(4)
Tax effect
Less: Net realized gains (losses) reclassified to earnings		(1)		1
Total other comprehensive income (loss)		(1)		1
After-tax
Less: Net realized gains (losses) reclassified to earnings	1	5	(1)	(3)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	1	5	(1)	(3)
Other
Pre-tax
Less: Net realized gains (losses) reclassified to earnings		3	(2)	7
Other comprehensive income (loss), before tax and net of reclassifications into Net income		3	(2)	7
Tax effect
Less: Net realized gains (losses) reclassified to earnings		1		2
Total other comprehensive income (loss)		1		2
After-tax
Less: Net realized gains (losses) reclassified to earnings		4	(2)	9
Other comprehensive income (loss), after tax and net of reclassifications into Net income		$ 4	$ (2)	$ 9