Cash and Cash Equivalents (Details) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents unrestricted		$ 409,980	$ 62,790
Restricted Cash	[1]	11,160	11,160
Cash and cash equivalents		$ 421,140	$ 73,950

[1] Includes cash placed on deposit with a financial institution to be held as cash collateral for the Company's outstanding letters of credit.