Number of shares that have been repurchased during the period and are being held in treasury.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
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-Subparagraph (SX 210.3-04)
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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Name:	us-gaap_TreasuryStockSharesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Share Repurchases (Details) - USD ($) shares in Millions	3 Months Ended
Share Repurchases (Details) - USD ($) shares in Millions	Mar. 31, 2022	Mar. 31, 2021	Oct. 31, 2020
Class of Stock [Line Items]
Payments for repurchase of common stock	$ 0	$ 600,000,000.0
2020 Share Repurchase Program
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount			$ 5,000,000,000
Repurchase of common stock, at cost, shares		2.2
Payments for repurchase of common stock		$ 600,000,000
Amount remaining under 2019 Share Repurchase Program	$ 2,800,000,000