Lease Commitments - Supplemental Cash Flow (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Cash Flow, Lessee [Abstract] [Abstract]
Operating cash flows from operating leases	$ (8,082)
Operating cash flows from finance leases	55
Financing cash flows from finance leases	(197)
Right-Of-Use Asset Obtained In Exchange For Lease Liability [Abstract] [Abstract]
Leased assets obtained in exchange for new finance lease liabilities	0
Leased assets obtained in exchange for new finance lease liabilities	$ 36