Financing Arrangements - Schedule of Maturities of Principal Obligations Under New Term Facility (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Less: current portion	$ (2,750)	$ (2,750)
Total long-term debt	264,130	$ 265,393
2017 Term Facility
Debt Instrument [Line Items]
Remainder of 2018	688
2019	2,750
2020	2,750
2021	2,750
2022	261,937
Total principal outstanding	270,875
Unamortized debt discount	(1,697)
Unamortized debt issuance costs	(2,298)
Total	266,880
Less: current portion	(2,750)
Total long-term debt	$ 264,130

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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