Derivative Instruments and Hedging Activities - Interest Rate Derivatives Designated as Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Amounts Related To Interest Rate Derivatives Included In Income Designated As Hedges Of Cash Flows [Line Items]
Amount of loss reclassified from accumulated other comprehensive loss to interest expense	$ (101,576)	$ (59,897)
Amount of (loss) gain recognized in other comprehensive income (loss)	(550)	2,751
Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Amounts Related To Interest Rate Derivatives Included In Income Designated As Hedges Of Cash Flows [Line Items]
Amount of loss reclassified from accumulated other comprehensive loss to interest expense	$ (290)	$ (1,451)