Debt - Schedule of Carrying Values of Debt (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total debt	$ 321,250	$ 323,500
Less: Unamortized issuance discount and issuance costs, net	4,454	5,179
Debt, current	103,282	2,032
Long term debt, net	$ 213,514	316,289
Revolving Credit Facility \| Domestic Line of Credit
Debt Instrument [Line Items]
Issuance date	Feb. 28, 2013
Maturity date	Apr. 30, 2022
Total debt	$ 25,000	$ 25,000
Revolving Credit Facility \| Minimum \| Domestic Line of Credit
Debt Instrument [Line Items]
Effective Interest Rate	5.54%	5.36%
Revolving Credit Facility \| Maximum \| Domestic Line of Credit
Debt Instrument [Line Items]
Effective Interest Rate	6.51%	5.46%
2017 Refinancing Facility Agreement
Debt Instrument [Line Items]
Issuance date	Apr. 30, 2017
Maturity date	Apr. 30, 2024
Total debt	$ 296,250	$ 298,500
2017 Refinancing Facility Agreement \| Minimum
Debt Instrument [Line Items]
Effective Interest Rate	6.20%	5.66%
2017 Refinancing Facility Agreement \| Maximum
Debt Instrument [Line Items]
Effective Interest Rate	6.81%	5.84%

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

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Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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- Definition

Date the debt instrument was issued, in CCYY-MM-DD format.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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-Publisher FASB
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-Publisher FASB
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- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

+ References

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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