Leases Leases - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Finance Lease, Right-of-Use Asset	$ 233,209	$ 367,164
Finance Lease Accumulated Depreciation	$ 9,972	$ 131,971
Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	5 years
Lessee, Operating Lease, Renewal Term	5 years
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	15 years
Lessee, Operating Lease, Renewal Term	10 years