Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Cumulative Foreign Currency Translation Gain Loss Recorded In Accumulated Other Comprehensive Income Loss For Terminated Net Investment In Foreign Operations Hedges	$ 124	$ 139
Counterparty Credit Derivative Exposure	18
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 6

The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121549185&loc=d3e80748-113994

Name:	us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant