Total Equity and Other Comprehensive Income (Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Pre-tax
Other comprehensive income (loss), before tax and net of reclassifications into Net income	$ 1,751	$ (433)
Tax effect
Total other comprehensive income (loss)	(423)	103
After-tax
Other comprehensive income (loss), after tax and net of reclassifications into Net income	1,328	(330)
Debt securities
Pre-tax
Net unrealized gains (losses)	748	(395)
Less: Net realized gains (losses) reclassified to earnings	(181)	(216)
Other comprehensive income (loss), before tax and net of reclassifications into Net income	929	(179)
Tax effect
Net unrealized gains (losses)	(182)	95
Less: Net realized gains (losses) reclassified to earnings	44	52
Total other comprehensive income (loss)	(226)	43
After-tax
Net unrealized gains (losses)	566	(300)
Less: Net realized gains (losses) reclassified to earnings	(137)	(164)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	703	(136)
Cash flow hedge derivatives
Pre-tax
Net unrealized gains (losses)	631	(626)
Less: Net realized gains (losses) reclassified to earnings	(194)	(376)
Other comprehensive income (loss), before tax and net of reclassifications into Net income	825	(250)
Tax effect
Net unrealized gains (losses)	(153)	150
Less: Net realized gains (losses) reclassified to earnings	47	90
Total other comprehensive income (loss)	(200)	60
After-tax
Net unrealized gains (losses)	478	(476)
Less: Net realized gains (losses) reclassified to earnings	(147)	(286)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	625	(190)
Pension and  other postretirement benefit plan adjustments
Pre-tax
Less: Net realized gains (losses) reclassified to earnings	(2)	(2)
Other comprehensive income (loss), before tax and net of reclassifications into Net income	(2)	(2)
Tax effect
Less: Net realized gains (losses) reclassified to earnings	1	0
Total other comprehensive income (loss)	1	0
After-tax
Less: Net realized gains (losses) reclassified to earnings	(1)	(2)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	(1)	(2)
Other
Pre-tax
Less: Net realized gains (losses) reclassified to earnings	(1)	(2)
Other comprehensive income (loss), before tax and net of reclassifications into Net income	(1)	(2)
Tax effect
Less: Net realized gains (losses) reclassified to earnings	2	0
Total other comprehensive income (loss)	2	0
After-tax
Less: Net realized gains (losses) reclassified to earnings	1	(2)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	$ 1	$ (2)