Derivative Financial Instruments - Changes in Net Loss on Cash Flow Hedges Included in Accumulated Other Comprehensive Loss (Details) - Interest rate swap agreements - Cash flow hedges - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Changes in Net Gain or Loss on Cash Flow Hedges Included in Accumulated Other Comprehensive Loss
Balance at the beginning of the period	$ (19,039)	$ (5,872)	$ (10,137)	$ (2,936)
Unrealized loss recognized in other comprehensive loss, net of tax	(2,290)	(4,775)	(12,063)	(7,926)
Reclassification to interest expense, net	1,717	87	2,588	302
Balance at the end of the period	$ (19,612)	$ (10,560)	$ (19,612)	$ (10,560)