Leases (Components of Lease Cost) (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2019	Sep. 30, 2019
Total finance lease cost		$ 1,832	$ 5,463
Selling, General and Administrative Expenses [Member]
Operating lease cost	[1]	9,921	29,181
Depreciation [Member]
Finance lease cost: Amortization of ROU assets		1,676	4,971
Interest Expense [Member]
Finance lease cost: Interest on lease liabilities		$ 156	$ 492

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