Cumulative Other Comprehensive Loss - Schedule of Amounts Recognized in Cumulative Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balance	$ 3,300,495	$ 3,260,447
Amounts reclassified from cumulative other comprehensive loss to cumulative net income pursuant to a change in accounting principle	(1,902)
Other comprehensive income before reclassifications	1,283	64
Amounts reclassified from cumulative other comprehensive loss to net income	372	49
Net current period other comprehensive income	1,655	113
Balance	3,183,998	3,300,495
AOCI Including Portion Attributable to Noncontrolling Interest
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balance	(95)	(208)
Balance	(342)	(95)
Unrealized Loss on Derivative Instruments
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balance	(456)	(208)
Amounts reclassified from cumulative other comprehensive loss to cumulative net income pursuant to a change in accounting principle	0
Other comprehensive income before reclassifications	84	(297)
Amounts reclassified from cumulative other comprehensive loss to net income	372	49
Net current period other comprehensive income	456	(248)
Balance	0	(456)
Unrealized Gain (Loss) on Marketable Securities
Amounts recognized in cumulative other comprehensive income (Loss) by component
Balance	361	0
Amounts reclassified from cumulative other comprehensive loss to cumulative net income pursuant to a change in accounting principle	(1,902)
Other comprehensive income before reclassifications	1,199	361
Amounts reclassified from cumulative other comprehensive loss to net income	0	0
Net current period other comprehensive income	1,199	361
Balance	$ (342)	$ 361