Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Name:	us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Stockholders' Equity (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020
Equity, Class of Treasury Stock [Line Items]
Shares repurchased	$ 91	$ 236	$ 30
Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (in shares)				9
Shares repurchased				$ 85
Stock repurchase program, remaining authorized repurchase amount				$ 1,300