Debt (Details 1) $ in Thousands	Dec. 31, 2017 USD ($)
Capital Leases
Capital leases, 2018	$ 7,559
Capital leases, 2019	7,918
Capital leases, 2020	2,428
Capital leases, 2021	2,620
Capital leases, 2022	1,379
Capital leases, Thereafter	0
Capital leases, Total	21,904
Debt
Debt, 2018	818,510
Debt, 2019	1,077,734
Debt, 2020	1,892,344
Debt, 2021	717,868
Debt, 2022	699,006
Debt, Thereafter	190,510
Debt, Total	5,395,972
Maturities of debt
Imputed interest	(1,033)
Present value of minimum capitalized lease payments	20,871
Current portion	(7,559)
Long-term capitalized lease obligation	$ 13,312