Lease Commitments - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost (a)	$ 7,750	$ 23,579
Amortization of finance lease assets	51	160
Interest on finance lease liabilities	1	3
Total finance lease cost	52	163
Net lease cost	7,802	23,742
Short-term lease, cost	1,981	5,382
Variable lease, cost	995	2,675
Cost of Sales
Lessee, Lease, Description [Line Items]
Operating lease cost (a)	6,318	19,249
Selling, General and Administrative Expenses
Lessee, Lease, Description [Line Items]
Operating lease cost (a)	$ 1,432	$ 4,330