Fair Value Measurements - Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
FAIR VALUE MEASUREMENTS
Unamortized discount and debt issuance costs, net	$ 7,798	$ 8,328
Credit Agreement, dated March 6, 2018, Term Loan B
FAIR VALUE MEASUREMENTS
Unamortized discount and debt issuance costs, net	6,900	7,900
Credit Agreement, dated March 6, 2018, Term Loan B \| Carrying Value
FAIR VALUE MEASUREMENTS
Debt	492,400	496,200
Credit Agreement, dated March 6, 2018, Term Loan B \| Recurring basis \| Level 3 \| Fair Value
FAIR VALUE MEASUREMENTS
Debt	487,500
Credit Agreement, dated March 6, 2018, Term Loan B \| Revolving credit facility \| Recurring basis \| Level 3 \| Fair Value
FAIR VALUE MEASUREMENTS
Debt		497,400
Seller Notes \| Carrying Value
FAIR VALUE MEASUREMENTS
Debt	$ 32,300	$ 900

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

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

+ References

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)(2)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

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+ References

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