Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Cash and cash equivalents	$ 716,799	$ 61,576	$ 93,153
Restricted cash	30,857	36,241	35,101
Total Cash and cash equivalents and Restricted cash shown in the Consolidated Statements of Cash Flows	$ 747,656	$ 97,817	$ 128,254