Derivative Instruments and Hedging Activity - Consolidated statements of operations and other comprehensive loss (Details) - Interest rate swap - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other comprehensive income (loss) - change in fair value and settlement of interest rate swaps	$ (70)	$ (7,418)	$ (36,739)	$ (14,617)
Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative Instruments, Amount of Income/(Loss) Reclassified from Accumulated OCI into Expense (Effective Portion)	$ 1,490	$ 22	$ 2,856	$ 366