Investment Securities (Contractual Maturity Distribution Of Debt Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Investment securities available-for-sale, Amortized Cost	$ 17,116	$ 14,752
Investment Securities, Available-for-sale	16,986	$ 15,028
Debt securities
Available-for-sale, Within one year, Amortized Cost	170
Available-for-sale, After one year through five years, Amortized Cost	3,098
Available-for-sale, After five years through ten years, Amortized Cost	1,290
Available-for-sale, After ten years, Amortized Cost	12,558
Investment securities available-for-sale, Amortized Cost	17,116
Available-for-sale, Within one year, Fair Value	172
Available-for-sale, After one year through five years, Fair Value	3,088
Available-for-sale, After five years through ten years, Fair Value	1,297
Available-for-sale, After ten years, Fair Value	12,429
Investment Securities, Available-for-sale	$ 16,986

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
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-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

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