Commitments and Contingencies - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Lease Costs
Operating lease costs before capitalized operating lease costs	$ 32,169	$ 33,235
Operating lease costs capitalized	(3,127)	(47)
Operating lease costs, net	29,043	33,188	$ 32,965
Finance Lease, Costs [Abstract]
Interest on financing leases	8,091	3,243	$ 8,069
Interest on financing leases capitalized	(2,378)	0
Interest on financing leases, net	5,713	3,243
Finance lease, right-of-use asset, amortization	1,200	1,219
Financing lease costs, net	$ 6,913	$ 4,462
Operating lease, weighted average discount rate, percent	4.71%
Operating lease, weighted average remaining lease term	27 years