Debt - Maturity of Debt (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Capital Leases
Capital leases, 2019	$ 7,364
Capital leases, 2020	4,729
Capital leases, 2021	4,040
Capital leases, 2022	2,732
Capital leases, 2023	1,213
Capital leases, Thereafter	5,162
Capital leases, Total	25,240
Debt
Debt, 2019	922,588
Debt, 2020	1,290,370
Debt, 2021	1,058,104
Debt, 2022	717,413
Debt, 2023	2,334,059
Debt, Thereafter	297,379
Debt, Total	6,619,913
Maturities of debt
Imputed interest	(3,467)
Present value of minimum capitalized lease payments	21,773
Current portion	(7,364)
Long-term capitalized lease obligation	$ 14,409