INDEBTEDNESS - Credit facility (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Current debt	$ 14,438	$ 13,243
Senior Secured Credit Facility [Member]
Debt Instrument, Term	5 years
Line of Credit Facility, Commitment Fee Percentage	0.40%
Senior Secured Credit Facility [Member] \| LIBOR [Member]
Debt Instrument, Basis Spread on Variable Rate	2.25%
Senior Secured Credit Facility [Member] \| LIBOR [Member] \| Minimum
Debt Instrument, Basis Spread on Variable Rate	1.50%
Senior Secured Credit Facility [Member] \| LIBOR [Member] \| Maximum
Debt Instrument, Basis Spread on Variable Rate	2.75%
Senior Secured Credit Facility [Member] \| Alternative Base Rate [Member] \| Minimum
Debt Instrument, Basis Spread on Variable Rate	0.50%
Senior Secured Credit Facility [Member] \| Alternative Base Rate [Member] \| Maximum
Debt Instrument, Basis Spread on Variable Rate	1.75%
Senior Secured Credit Facility [Member] \| Term Loan [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 72,200
Quarterly payment	6,800
Current debt	6,800
Senior Secured Credit Facility [Member] \| Delayed Draw Term Loan [Member]
Line of Credit Facility, Maximum Borrowing Capacity	118,000
Quarterly payment	8,100
Current debt	8,100
Senior Secured Credit Facility [Member] \| Revolver [Member]
Line of Credit Facility, Maximum Borrowing Capacity	75,000
Amount borrowed	7,500
Line of Credit Facility, Remaining Borrowing Capacity	$ 67,500
Senior Secured Credit Facility [Member] \| Revolver [Member] \| Minimum
Line of Credit Facility, Commitment Fee Percentage	0.25%
Senior Secured Credit Facility [Member] \| Revolver [Member] \| Maximum
Line of Credit Facility, Commitment Fee Percentage	0.50%

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

Amount of the required periodic payments including both interest and principal payments.

+ References

+ Details

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- 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.

+ References

+ Details

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- Details

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- Details

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- Details

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- Details

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