Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Cash and cash equivalents	$ 348,366	$ 193,685
Restricted cash	80,974	8,416
Total cash, cash equivalents and restricted cash	429,340	202,101	$ 213,391	$ 119,863
Restricted cash held to repay outstanding principal balance of Convertible Notes	69,900
Joint venture cash and cash equivalents
Cash and cash equivalents	179,380	149,925
Cash and cash equivalents available for general corporate purposes
Cash and cash equivalents	$ 168,986	$ 43,760