Lease - Other lease information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Leases [Abstract]
Operating cash flows from operating leases	$ 18,882
Operating cash flows from finance leases	388
Financing cash flows from finance leases	1,461
Right-of-use assets obtained in exchange for lease obligations, operating leases	$ 36,369
Right-of-use assets obtained in exchange for lease obligations, finance leases		$ 6,818
Weighted-average remaining lease term (years), operating leases	5 years 3 months 26 days
Weighted-average remaining lease term (years), finance leases	5 years 9 months 22 days
Weighted-average discount rate, operating leases	4.25%
Weighted-average discount rate, finance leases	8.46%