Leases - Supplemental cash flow information and other related information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Leases [Abstract]
Operating cash flows from operating leases	$ 14,976
Operating cash flows from finance leases	611
Financing cash flows from finance leases	837	$ 0
ROU assets obtained in exchange for new lease obligations - Operating leases	$ 4,008
Weighted average remaining term - Operating leases	8 years 6 months
Weighted average remaining lease term - Finance leases	7 years 8 months 12 days
Weighted average discount rate - Operating leases	3.70%
Weighted average discount rate - Finance leases	6.00%