Quarterly report pursuant to Section 13 or 15(d)

Leases Future maturities of lease liabilities (Details)

v3.19.1
Leases Future maturities of lease liabilities (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Jan. 01, 2019
Dec. 31, 2018
Mar. 31, 2018
Leases [Abstract]        
Operating Leases, Future Minimum Payments Due, Next Twelve Months $ 56,274      
Lessee, Operating Lease, Liability, Payments, Due Year Two 68,962      
Lessee, Operating Lease, Liability, Payments, Due Year Three 61,194      
Lessee, Operating Lease, Liability, Payments, Due Year Four 56,408      
Lessee, Operating Lease, Liability, Payments, Due Year Five 51,764      
Finance Lease, Liability, Payments, Due after Year Five 167,800      
Finance Lease, Liability, Payments, Due 462,402      
Unrecorded Unconditional Purchase Obligation, Imputed Interest (65,356)      
Operating Lease, Liability 397,046      
Operating Lease, Liability, Current (59,214) $ (57,207) $ 0 $ 0
Operating Lease, Liability, Noncurrent $ 337,832 $ 329,865 $ 0 $ 0