Leases - Cash Payments Included in Measurement of Lease liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Finance leases
Operating cash flows included in other activities, net	$ 265
Financing cash flows included in payments under finance lease obligations	513
Operating leases
Operating cash flows (fixed payments) included in other activities, net	1,246
Operating cash flows (liability reduction) included in other activities, net	$ 941