Derivatives - Interest-Rate Derivatives (Details) $ in Millions	6 Months Ended
Jun. 30, 2021 USD ($)
Interest Rate Swaps
Derivative [Line Items]
Net cash payments related to settlements	$ 47
Collateral paid with respect to interest rate swap agreements	49
Interest Rate Swap, 6.348%
Derivative [Line Items]
Notional Principal Amount	$ 400
Weighted-Average Interest Rate	6.348%
Interest Rate Swap, 6.662%
Derivative [Line Items]
Notional Principal Amount	$ 350
Weighted-Average Interest Rate	6.662%
Interest Rate Swap, 6.709%
Derivative [Line Items]
Notional Principal Amount	$ 275
Weighted-Average Interest Rate	6.709%
Interest Rate Swap, 6.445%
Derivative [Line Items]
Notional Principal Amount	$ 450
Weighted-Average Interest Rate	6.445%

Derivative Instrument, Collateral Returned (Paid)

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- Definition

Average fixed interest rate related to the group of interest rate derivatives.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

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- Definition

The net cash outflow or inflow from derivative instruments during the period, which are classified as financing activities, excluding those designated as hedging instruments.

+ References

No definition available.

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