Leases - Total Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Amortization of Right-of-Use Assets	$ 396	$ 1,302
Interest on Lease Liabilities	83	296
Total Finance Lease Cost	479	1,598
Operating Lease Cost	27,900	84,911
Sublease Receipts	(628)	(2,399)
Total Lease Cost	28,379	86,509
Operating Lease Cost Classified within Operating Expenses
Lessee, Lease, Description [Line Items]
Operating Lease Cost	27,647	84,789
Operating Lease Cost Classified within Restructuring Expenses, Net
Lessee, Lease, Description [Line Items]
Operating Lease Cost	$ 881	$ 2,521