Restructuring and Related Reorganization Costs - Narrative (Details) - Corporate Restructuring Plan - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,344	$ 3,355
Restructuring reserve	1,089	1,089	$ 2,354	$ 908	$ 0
Restructuring charges incurred to date	12,152	12,152
Accrued Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	1,089	1,089	2,124
Accounts Payable
Restructuring Cost and Reserve [Line Items]
Restructuring reserve			230
Retention and Personnel Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	823	2,217
Restructuring reserve	1,089	1,089	1,956	708	0
Restructuring charges incurred to date	7,314	7,314
Acceleration of Stock-Based Compensation
Restructuring Cost and Reserve [Line Items]
Restructuring charges	89	279
Restructuring charges incurred to date	2,011	2,011
Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Restructuring charges	93	236
Restructuring charges incurred to date	673	673
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring charges	339	623
Restructuring reserve	0	0	$ 398	$ 200	$ 0
Restructuring charges incurred to date	$ 2,154	$ 2,154