Condensed Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (19,618)	$ 18,930	$ (11,330)	$ 28,786
Other comprehensive income (loss):
Unrealized gain (loss) on valuation of interest rate swap agreements	(1,709)	(12,346)	(19,404)	(19,736)
Less: amount reclassified into interest expense	2,317	169	3,113	318
Other comprehensive income (loss)	608	(12,177)	(16,291)	(19,418)
Comprehensive income (loss)	$ (19,010)	$ 6,753	$ (27,621)	$ 9,368