Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018
Leases [Abstract]
Operating cash flows from finance leases	$ 7
Operating cash flows from operating leases	2,108
Financing cash flows from finance leases	$ 76	$ 76	$ 66