Capital Stock (Summary of Cash Dividend Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Banking Regulation, Total Capital [Abstract]
Declaration date	Apr. 18, 2023	Jan. 24, 2023	Apr. 19, 2022	Jan. 25, 2022
Record date	Jun. 09, 2023	Mar. 10, 2023	Jun. 10, 2022	Mar. 10, 2022
Payment date	Jun. 23, 2023	Mar. 24, 2023	Jun. 24, 2022	Mar. 25, 2022
Cash dividends per share	$ 1.48	$ 1.48	$ 1.28	$ 1.28
Total payment	$ 350	$ 351	$ 309	$ 309	$ 701	$ 618

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Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

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Date the declared dividend will be paid, in YYYY-MM-DD format.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482913/230-10-50-3

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Date the dividend to be paid was declared, in YYYY-MM-DD format.

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Date the holder must own the stock to be entitled to the dividend, in YYYY-MM-DD format.

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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-15

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