Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Capital Leases, Future Minimum Payments Due, Next Twelve Months	$ 35,237	$ 46,998
Capital Leases, Future Minimum Payments Due in Two Years	41,702	51,943
Capital Leases, Future Minimum Payments Due in Three Years	59,553	57,881
Capital Leases, Future Minimum Payments Due in Four Years	23,352	21,842
Capital Leases, Future Minimum Payments Due in Five Years	16,569	15,587
Capital Leases, Future Minimum Payments Due Thereafter	39,990	40,447
Capital Leases, Future Minimum Payments Due	216,403	234,698
Capital Leases, Future Minimum Payments, Interest Included in Payments	(22,445)	(22,746)
Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments	193,958	211,952
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	8,527	11,295
Lessee, Operating Lease, Liability, Payments, Due Year Two	10,873	9,550
Lessee, Operating Lease, Liability, Payments, Due Year Three	9,460	8,251
Lessee, Operating Lease, Liability, Payments, Due Year Four	8,388	7,282
Lessee, Operating Lease, Liability, Payments, Due Year Five	6,241	5,397
Lessee, Operating Lease, Liability, Payments, Due after Year Five	43,574	37,841
Lessee, Operating Lease, Liability, Payments, Due	87,063	$ 79,616
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(23,373)
Operating Lease, Liability	$ 63,690
Number of Leases-Operating	1
Lease Liability Payments Remainder Of Fiscal Year	$ 43,764
Lease Liability Payments Due Year Two	52,575
Lease Liability Payments Due Year Three	69,013
Lease Liability Payments Due Year Four	31,740
Lease Liability Payments Due Year Five	22,810
Lease Liability Payments Due After Year Five	83,564
Lease Liability Payments Due	303,466
Lease Liability Undiscounted Excess Amount	45,818
Lease Liability	257,648
Operating Lease, Lease Income	700
Lessor, Operating Lease, Payments to be Received, Next Twelve Months	1,949
Lessor, Operating Lease, Payments to be Received, Two Years	1,660
Lessor, Operating Lease, Payments to be Received, Three Years	1,312
Lessor, Operating Lease, Payments to be Received, Four Years	996
Lessor, Operating Lease, Payments to be Received, Five Years	426
Lessor, Operating Lease, Payments to be Received, Thereafter	94
Lessor, Operating Lease, Payments to be Received	6,437
Lease, Cost [Abstract]
Finance Lease, Right-of-Use Asset, Amortization	10,964
Finance Lease, Interest Expense	1,831
Finance Lease Cost	12,795
Operating Lease, Cost	3,194
Variable Lease, Cost	372
Lease, Cost	$ 16,361