Organization and Basis of Presentation - Cash, Cash Equivalents and Restricted Cash And Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents-unrestricted	$ 558,446	$ 70,087	$ 74,031	$ 134,465
Cash and cash equivalents-restricted	10,629	11,007	17,695	16,930
Total unrestricted and restricted cash and cash equivalents shown in the condensed consolidated statement of cash flows	$ 569,075	$ 81,094	$ 91,726	$ 151,395