Derivatives - Effect of Derivative Instruments on Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Effect of derivative instruments on results of operations
Total amount of interest expense in which the effects of cash flow hedges are recorded	$ 25,221	$ 27,401	$ 80,664	$ 76,972
Interest Rate Swaps
Effect of derivative instruments on results of operations
Pre-tax loss recognized in other comprehensive income (loss)	(87)	(933)	(8,399)	(7,761)
Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense	(1,271)	482	(2,594)	2,199
Total amount of interest expense in which the effects of cash flow hedges are recorded	$ 25,221	$ 27,401	$ 80,664	$ 76,972