Leases (Components of Lease Cost) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Total finance lease cost	$ 1,824
Selling, General and Administrative Expenses [Member]
Operating lease cost	9,567	[1]
Depreciation [Member]
Finance lease cost: Amortization of ROU assets	1,644
Interest Expense [Member]
Finance lease cost: Interest on lease liabilities	$ 180

[1] Includes short-term leases and variable lease costs, which are not material.