Commitments and Contingencies - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Lease Costs
Operating lease costs before capitalized operating lease costs	$ 7,567	$ 7,751	$ 22,702	$ 24,486
Operating lease costs capitalized	(1,010)	(778)	(2,699)	(2,315)
Operating lease costs, net	6,557	6,973	20,003	22,171
Finance Lease, Costs [Abstract]
Interest on financing leases	1,229	2,198	4,215	6,010
Interest on financing leases capitalized	0	(588)	0	(2,378)
Interest on financing leases, net	1,229	1,610	4,215	3,632
Finance lease, right-of-use asset, amortization	180	304	540	914
Financing lease costs, net	$ 1,409	$ 1,914	$ 4,755	$ 4,546
Operating lease, weighted average discount rate, percent	4.59%		4.59%
Operating lease, weighted average remaining lease term	28 years		28 years