Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Current restricted cash	$ 31,184	$ 40,732
Non-current restricted cash	32,800	15,700
Secured Debt
Restricted Cash and Cash Equivalents Items [Line Items]
Non-current restricted cash	32,800		$ 16,400
Held in Trust Deposits
Restricted Cash and Cash Equivalents Items [Line Items]
Current restricted cash	29,500	38,400
Held for Advertising Activity Deposits
Restricted Cash and Cash Equivalents Items [Line Items]
Current restricted cash	$ 1,600	$ 2,300