Debt - Interest Rate Swaps (Details) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($) outstanding_contract derivative_instrument	Dec. 31, 2020 USD ($) outstanding_contract
Derivative [Line Items]
Number of contracts \| outstanding_contract	31	167
Interest rate swap contracts total notional value	$ 1,463,990	$ 1,830,063
Interest rate swaps
Derivative [Line Items]
Number of contracts \| derivative_instrument	4
Interest rate swap contracts total notional value	$ 1,400,000
Term of contract	30 days
Loss on release of interest rate swap recognized in AOCI	$ 82,300
Net negative fair value (liability)	(70,700)	(109,200)
Interest rate swaps \| Accumulated Other Comprehensive Loss, Net
Derivative [Line Items]
Net negative fair value (liability)	$ (61,800)	$ (78,100)
Interest rate swaps \| Minimum
Derivative [Line Items]
Fixed interest rate	2.13%
Interest rate swaps \| Maximum
Derivative [Line Items]
Fixed interest rate	3.04%

Amount, after tax, of accumulated gain (loss) on derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=124509347&loc=d3e637-108580

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- Definition

Fixed interest rate related to the interest rate derivative.

+ References

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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.

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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
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The number of derivative instruments of a particular group held by the entity.

+ References

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-Publisher FASB
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- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Fair value of all derivatives designated as interest rate fair value hedging instruments.

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