Business combination acquisition related costs including amortization of intangible assets.

No definition available.

Name:	ctg_BusinessCombinationAcquisitionRelatedCostsIncludingAmortizationOfIntangibleAssets
Namespace Prefix:	ctg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Business combination contingent consideration earn-out payments.

+ References

No definition available.

+ Details

Name:	ctg_BusinessCombinationContingentConsiderationEarnOutPayments
Namespace Prefix:	ctg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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.

+ Details

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

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

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

- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents a description of the basis for determining the amount of the payment recorded.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Publisher FASB
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-Topic 805
-SubTopic 30
-Section 25
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6411-128476

+ Details

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

- Definition

Fair value of contingent consideration in a business combination that is classified in shareholders' equity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

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

- Definition

Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section S99
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6897108&loc=SL6897125-166521

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Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- 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)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

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-Publisher FASB
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-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ctg_SoftCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Acquisitions - Additional Information (Details) - Soft Company [Member] $ in Thousands, € in Millions			3 Months Ended	6 Months Ended
	Feb. 15, 2018 USD ($)	Feb. 15, 2018 EUR (€)	Jun. 29, 2018 USD ($)	Jun. 29, 2018 USD ($)	Mar. 30, 2018
Business Acquisition [Line Items]
Business acquisition, percentage acquired	100.00%				100.00%
Payments to acquire business	$ 16,910	€ 13.6
Foreign currency exchange rate	1.2392
Earn-out contingency liability, basis for amount				The Company has a contingent consideration liability related to an earn-out provision which a portion will be payable in each period subject to the achievement by Soft Company of certain revenue and EBIT targets for fiscal 2017, 2018, and 2019. There is no payout if the achievement on either target is below a certain target threshold.
Fair value of acquisition	$ 2,000
Earn-out contingency liability			$ 900	$ 900
Acquisition related costs including amortization of intangible assets			$ 400	$ 900