Investment Securities (Schedule of Unrealized Loss on Investments) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	$ 24,982	$ 21,288
Debt securities, available-for-sale, unrealized loss, less than 12 months	(1,553)	(373)
Debt securities, available-for-sale, fair value, 12 months or longer	6,059	896
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(685)	(48)
U.S. Treasury and federal agencies
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	1,952	1,682
Debt securities, available-for-sale, unrealized loss, less than 12 months	(93)	(20)
Debt securities, available-for-sale, fair value, 12 months or longer	425	0
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(37)	0
U.S. States and political subdivisions
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	541	160
Debt securities, available-for-sale, unrealized loss, less than 12 months	(44)	(3)
Debt securities, available-for-sale, fair value, 12 months or longer	41	31
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(3)	(1)
Foreign government
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	115	76
Debt securities, available-for-sale, unrealized loss, less than 12 months	(5)	(2)
Debt securities, available-for-sale, fair value, 12 months or longer	26	7
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(3)	0
Agency mortgage-backed securities
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	13,237	12,244
Debt securities, available-for-sale, unrealized loss, less than 12 months	(709)	(223)
Debt securities, available-for-sale, fair value, 12 months or longer	4,416	38
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(469)	(1)
Mortgage-backed residential
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	4,716	3,243
Debt securities, available-for-sale, unrealized loss, less than 12 months	(319)	(34)
Debt securities, available-for-sale, fair value, 12 months or longer	19	22
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(1)	0
Agency mortgage-backed commercial
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	2,713	2,553
Debt securities, available-for-sale, unrealized loss, less than 12 months	(292)	(70)
Debt securities, available-for-sale, fair value, 12 months or longer	868	749
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(141)	(43)
Asset-backed
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	459	360
Debt securities, available-for-sale, unrealized loss, less than 12 months	(16)	(3)
Debt securities, available-for-sale, fair value, 12 months or longer	3	0
Debt securities, available-for-sale, unrealized loss, 12 months or longer	0	0
Corporate debt
Debt Securities [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	1,249	970
Debt securities, available-for-sale, unrealized loss, less than 12 months	(75)	(18)
Debt securities, available-for-sale, fair value, 12 months or longer	261	49
Debt securities, available-for-sale, unrealized loss, 12 months or longer	$ (31)	$ (3)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 50
-Paragraph 5
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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