Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases
Operating lease cost	$ 40,831	$ 205,815
Short-term lease cost	2,915	9,141
Amortization of right-of-use assets	7,187	17,100
Interest on lease liabilities	2,352	4,632
Total finance lease cost	9,539	21,732
Total lease costs	53,285	236,688
Lease expense	$ 25,000	$ 159,000