Leases - Lessee Disclosure, Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lease Cost:
Operating lease cost	$ 11,331	$ 18,334
Short-term lease cost	23,840	42,929
Total Lease Cost	$ 35,171	$ 61,263