Term of the interest rate that fluctuates over time as a result of an underlying benchmark interest rate or index.

No definition available.

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Namespace Prefix:	gvp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents the number of letters of credit on which the entity is contingently liable.

+ References

No definition available.

+ Details

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Namespace Prefix:	gvp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Refers to the percentage of letter of credit fees per annum.

+ References

No definition available.

+ Details

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Namespace Prefix:	gvp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	gvp_TermLoanAbstract
Namespace Prefix:	gvp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
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-Section 50
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-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- 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

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 10
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-Paragraph 1
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period remaining on line of credit facility before it terminates, 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_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

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=109250915&loc=d3e13433-108611

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

- 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

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
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

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

- Definition

Expenses paid for obtaining loans which includes expenses such as application and origination fees.

+ References

No definition available.

+ Details

Name:	us-gaap_LoanProcessingFee
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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

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

- 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.

+ References

+ Details

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

- References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
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-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

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

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
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Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
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- Details

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Balance Type:
Period Type:

- Details

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Period Type:

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Name:	us-gaap_LineOfCreditFacilityAxis=gvp_CitizenSBankMember
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Long-Term Debt (Details) $ in Thousands		12 Months Ended
Long-Term Debt (Details) $ in Thousands	May 11, 2018 USD ($)	Dec. 31, 2018 USD ($) Letter Contract	Dec. 31, 2017 USD ($) Letter
Line of Credit Facility [Abstract]
Number of letters of credit \| Letter		5
Long-term Debt, Current and Noncurrent [Abstract]
Long-term debt, less current portion		$ 6,610	$ 0
LIBOR [Member]
Line of Credit Facility [Abstract]
Term of variable rate		1 month
Line of Credit [Member]
Line of Credit Facility [Abstract]
Outstanding letter of credit balance			$ 800
BB&T Bank [Member]
Line of Credit Facility [Abstract]
Number of letters of credit \| Letter		0
BB&T Bank [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Abstract]
Number of letters of credit \| Letter			3
Outstanding letter of credit balance			$ 900
Citizen's Bank [Member]
Line of Credit Facility [Abstract]
Number of letters of credit \| Contract		5
Citizen's Bank [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Abstract]
Long-term debt		$ 0	0
Principal amount of the line of credit	$ 5,000	$ 5,000
Number of letters of credit \| Letter		5
Amount available at the reporting date		$ 2,700
Outstanding letter of credit balance		$ 2,300
Line of credit facility expiration period		3 years
Percentage of letter of credit fees per annum		1.25%
Maturity date		Dec. 29, 2019
Long-term Debt, Current and Noncurrent [Abstract]
Long-term debt, net of discount		$ 0	$ 0
Citizen's Bank [Member] \| Revolving Credit Facility [Member] \| LIBOR [Member]
Line of Credit Facility [Abstract]
Debt instrument, basis spread on variable rate		2.25%
Term of variable rate		1 month
Delayed Draw Term Loan [Member]
Line of Credit Facility [Abstract]
Long-term debt		$ 8,512
Long-term Debt, Current and Noncurrent [Abstract]
Long-term debt, net of discount		8,512
Long-term debt, net of discount		1,902
Long-term debt, less current portion		$ 6,610
Delayed Draw Term Loan [Member] \| Minimum [Member]
Line of Credit Facility [Abstract]
Debt instrument, basis spread on variable rate		2.00%
Delayed Draw Term Loan [Member] \| Maximum [Member]
Line of Credit Facility [Abstract]
Debt instrument, basis spread on variable rate		2.75%
Delayed Draw Term Loan [Member] \| Citizen's Bank [Member]
Line of Credit Facility [Abstract]
Line of credit facility term		5 years
Delayed Draw Term Loan [Member] \| Citizen's Bank [Member] \| Maximum [Member]
Line of Credit Facility [Abstract]
Line of credit facility expiration period		18 months
Delayed Draw Term Loan [Member] \| Citizen's Bank [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Abstract]
Principal amount of the line of credit	25,000
True North Consulting, LLC [Member]
Term Loan [Abstract]
Cash purchase price	9,915
Proceeds from issuance of debt	10,300
True North Consulting, LLC [Member] \| Delayed Draw Term Loan [Member]
Line of Credit Facility [Abstract]
Line of credit facility term		5 years
Maturity date		May 11, 2023
Term Loan [Abstract]
Proceeds from issuance of debt	10,300
Repayments of debt	$ 500
Debt issuance costs		$ 70
Loan origination fees		$ 75
True North Consulting, LLC [Member] \| Delayed Draw Term Loan [Member] \| LIBOR [Member]
Line of Credit Facility [Abstract]
Term of variable rate		1 month
True North Consulting, LLC [Member] \| Delayed Draw Term Loan [Member] \| Minimum [Member] \| LIBOR [Member]
Line of Credit Facility [Abstract]
Debt instrument, basis spread on variable rate		2.00%
True North Consulting, LLC [Member] \| Delayed Draw Term Loan [Member] \| Maximum [Member] \| LIBOR [Member]
Line of Credit Facility [Abstract]
Debt instrument, basis spread on variable rate		2.75%