Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets:
Cash equivalents	$ 1,086,402	$ 759,257
Restricted cash	6,388	4,322
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	1,086,402	759,257
Restricted cash	6,388	4,322
Liabilities:
Derivative Liability	3,847	619
Fair Value, Measurements, Recurring | Quoted Market Prices in Active Markets (Level 1)
Assets:
Cash equivalents	0	0
Restricted cash	2,048	2,015
Liabilities:
Derivative Liability	0	0
Fair Value, Measurements, Recurring | Other Observable Inputs (Level 2)
Assets:
Cash equivalents	1,086,402	759,257
Restricted cash	4,340	2,307
Liabilities:
Derivative Liability	3,847	619
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Assets:
Cash equivalents	0	0
Restricted cash	0	0
Liabilities:
Derivative Liability	$ 0	$ 0