Restructuring and Other Charges - Restructuring Reserve Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Severance Costs	$ 864	$ (42)
Business Combination, Integration Related Costs	517	193
Restructuring and Business Combination Related Expenses, Facility Reductions	190	$ 0
Balance accrued as of December 31, 2013	2,774
Restructuring Charges	1,062
Restructuring Reserve, Accrual Adjustment	(5)
Expenditures	(2,307)
Balance accrued as of September 30, 2014	1,524
Severance, Payroll Taxes and Other Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Balance accrued as of December 31, 2013	2,774
Restructuring Charges	872
Restructuring Reserve, Accrual Adjustment	(5)
Expenditures	(2,297)
Balance accrued as of September 30, 2014	1,344
Lease Abandonment Charges [Member]
Restructuring Cost and Reserve [Line Items]
Balance accrued as of December 31, 2013	0
Restructuring Charges	190
Restructuring Reserve, Accrual Adjustment	0
Expenditures	(10)
Balance accrued as of September 30, 2014	$ 180