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Derivative Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
Derivative Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 20, 2018	Apr. 05, 2017
Derivative [Line Items]
Interest expense related to payments on interest rate swaps	$ 26,593	$ 28,749	$ 30,523
Increase (decrease) in fair value of derivative contracts	(29,843)	895	1,449
Interest Rate Swap
Derivative [Line Items]
Derivative instruments, notional amount					$ 400,000
Ineffectiveness recognized	0	0	$ 0
Interest Rate Swap \| Term Loan I
Derivative [Line Items]
Aggregate principal amount					400,000
Expiration December 17 2021 [Member] \| Term Loan I
Derivative [Line Items]
Derivative instruments, notional amount					200,000
Expiration April 27 2022 [Member] \| Term Loan I
Derivative [Line Items]
Derivative instruments, notional amount					$ 200,000
Interest Rate Swap Two [Member]
Derivative [Line Items]
Derivative instruments, notional amount				$ 400,000
Interest Rate Swap Two [Member] \| Term Loan
Derivative [Line Items]
Aggregate principal amount				400,000
Expiration December 17 2023 [Member] \| Term Loan II
Derivative [Line Items]
Derivative instruments, notional amount				200,000
Expiration April 27 2024 [Member] \| Term Loan II
Derivative [Line Items]
Derivative instruments, notional amount				200,000
Interest Rate Swap Three [Member] \| Term Loan III
Derivative [Line Items]
Derivative instruments, notional amount				200,000
Expiration Dec 17 2023 [Member] \| Term Loan III
Derivative [Line Items]
Aggregate principal amount				100,000
Expiration Apr 27 2024 [Member] \| Term Loan III
Derivative [Line Items]
Aggregate principal amount				$ 100,000
Cash flow hedging \| Interest Rate Swap
Derivative [Line Items]
Derivative Asset, fair Value		5,300
Derivative Liability, fair Value	19,900	3,000
Derivative, Fair Value, Net	$ (19,916)	$ 2,343