Leases - Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Maturities of lease liabilities: Operating lease
2019 (remaining three months)	$ 17,053
2020	59,995
2021	45,155
2022	22,108
2023	9,208
Thereafter	8,444
Total lease payments	161,963
Less: Imputed interest	(11,430)
Total	150,533
Less: Current portion	(57,737)
Long-term portion of lease obligations	92,796
Maturities of lease liabilities: Finance lease
2019 (remaining three months)	21,132
2020	85,965
2021	82,577
2022	48,305
2023	40,942
Thereafter	30,707
Total lease payments	309,628
Less: Imputed interest	(57,924)
Total	251,704	$ 66,984
Less: Current portion	(63,483)
Long-term portion of lease obligations	188,221
Future minimum payments for total lease liabilities
2019 (remaining three months)	38,185
2020	145,960
2021	127,732
2022	70,413
2023	50,150
Thereafter	39,151
Total lease payments	471,591
Less: Imputed interest	(69,354)
Total	402,237
Less: Current portion	(121,220)
Long-term portion of lease obligations	$ 281,017