Investment Securities (Investment Portfolio) (Details) - USD ($) $ in Millions		Sep. 30, 2022	Dec. 31, 2021
Available-for-sale securities
Amortized cost		$ 35,214	$ 33,650
Gross unrealized gains		0	358
Gross unrealized losses		(5,601)	(421)
Fair value	[1]	29,613	33,587
Held-to-maturity securities
Amortized cost		1,084	1,170
Gross unrealized gains		0	48
Gross unrealized losses		(181)	(14)
Fair value		903	1,204
Hedged asset, fair value hedge, cumulative increase (decrease)		25
Debt securities, available-for-sale, accrued interest receivable		89	84
Debt securities, held-to-maturity, accrued interest receivable		2	3
Asset Pledged as Collateral with Right
Available-for-sale securities
Fair value		3,400	203
Held-to-maturity securities
Securities with the right to sell or pledge		274	203
Asset Pledged as Collateral with Right | Federal Home Loan Bank advances
Held-to-maturity securities
Securities with the right to sell or pledge		3,100
Operating Segments | Insurance operations
Held-to-maturity securities
Deposit securities		12	13
U.S. Treasury and federal agencies
Available-for-sale securities
Amortized cost		2,276	2,173
Gross unrealized gains		0	2
Gross unrealized losses		(277)	(20)
Fair value		1,999	2,155
U.S. States and political subdivisions
Available-for-sale securities
Amortized cost		843	841
Gross unrealized gains		0	27
Gross unrealized losses		(106)	(4)
Fair value		737	864
Foreign government
Available-for-sale securities
Amortized cost		153	157
Gross unrealized gains		0	2
Gross unrealized losses		(12)	(2)
Fair value		141	157
Agency mortgage-backed residential
Available-for-sale securities
Amortized cost		19,885	19,044
Gross unrealized gains		0	219
Gross unrealized losses		(3,210)	(224)
Fair value		16,675	19,039
Held-to-maturity securities
Amortized cost		1,084	1,170
Gross unrealized gains		0	48
Gross unrealized losses		(181)	(14)
Fair value		903	1,204
Mortgage-backed residential
Available-for-sale securities
Amortized cost		5,227	4,448
Gross unrealized gains		0	11
Gross unrealized losses		(847)	(34)
Fair value		4,380	4,425
Agency mortgage-backed commercial
Available-for-sale securities
Amortized cost		4,406	4,573
Gross unrealized gains		0	66
Gross unrealized losses		(883)	(113)
Fair value		3,523	4,526
Asset-backed
Available-for-sale securities
Amortized cost		490	536
Gross unrealized gains		0	1
Gross unrealized losses		(23)	(3)
Fair value		467	534
Corporate debt
Available-for-sale securities
Amortized cost		1,934	1,878
Gross unrealized gains		0	30
Gross unrealized losses		(243)	(21)
Fair value		$ 1,691	$ 1,887

[1] Refer to Note 7 for discussion of investment securities pledged as collateral.