Leases Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Finance lease cost
Amortization of leased assets	$ 135	$ 519	$ 270	$ 728
Interest of lease liabilities	26	309	139	339
Operating lease cost
Operating lease cost	51,006	48,639	98,223	98,353
Short-term lease cost	6,884	3,509	13,598	6,958
Variable lease cost	25,568	31,653	55,383	59,770
Total lease cost	$ 83,619	$ 84,629	$ 167,613	$ 166,148