Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Cash equivalents	$ 1,158,265	$ 1,086,402
Restricted cash	4,930	6,388
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	1,158,265	1,086,402
Restricted cash	4,930	6,388
Liabilities:
Interest rate collar	19,508	3,847
Fair Value, Measurements, Recurring | Quoted Market Prices in Active Markets (Level 1)
Assets:
Cash equivalents	400,839	0
Restricted cash	2,053	2,048
Liabilities:
Interest rate collar	0	0
Fair Value, Measurements, Recurring | Other Observable Inputs (Level 2)
Assets:
Cash equivalents	757,426	1,086,402
Restricted cash	2,877	4,340
Liabilities:
Interest rate collar	19,508	3,847
Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0	0
Restricted cash	0	0
Liabilities:
Interest rate collar	$ 0	$ 0