Derivative Instruments and Hedging Activities (Impact of Financial Instruments on Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Effect of the Company's derivative financial instruments on the income statement
Total Interest Expense Presented in the Results of Operations in which the Effects of Cash Flow Hedges are Recorded	$ 31,872	$ 28,829	$ 98,717	$ 76,358
Interest expense
Effect of the Company's derivative financial instruments on the income statement
Amount of (Loss) Gain Reclassified from AOCI into Operations	(4,121)	(199)	(8,441)	21
Interest rate derivatives
Effect of the Company's derivative financial instruments on the income statement
Amount of (Loss) Gain Reclassified from AOCI into Operations	800		2,400
Cash flow hedging | Interest rate derivatives
Effect of the Company's derivative financial instruments on the income statement
Amount of Loss Recognized in AOCI on Derivative	$ 1,802	$ (6,406)	$ (32,999)	$ (25,238)