Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Leases
Operating lease cost	$ 18,798	$ 18,118	$ 33,581	$ 35,849
Short-term lease cost (1)	3,726	2,891	7,198	5,558
Amortization of right-of-use assets	17,830	17,755	35,659	35,659
Interest on lease liabilities	3,880	5,443	8,168	11,256
Total finance lease cost	21,710	23,198	43,827	46,915
Total lease costs	44,234	$ 44,207	84,606	$ 88,322
Operating lease assets	$ 293,570		$ 293,570		$ 104,271