Supplemental Disclosure of Cash Flow Information - Cash and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Cash and cash equivalents	$ 241,391	$ 398,267
Restricted cash	33,305	27,683
Long-term restricted cash	40,663	24,268
Total cash, cash equivalents, and restricted cash shown in the condensed consolidated statements of cash flows	$ 315,359	$ 450,218	$ 200,098	$ 282,546