Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 5,822	$ 5,075	$ 17,839	$ 15,106
Short-term lease expense	3,758	9,556	17,061	30,269
Total lease expense	$ 9,580	$ 14,631	$ 34,900	$ 45,375