Equity-Based Compensation Options Exercisable (Details) (USD $)	12 Months Ended
Dec. 31, 2014
2010 Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	477,722
Outstanding, weighted-average exercise price	$ 15.56
Weighted average remaining contractual life	10 years 1 month
Aggregate intrinsic value	$ 0
Equity Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	1,868,597
Outstanding, weighted-average exercise price	$ 4.82
Weighted average remaining contractual life	3 years 11 months
Aggregate intrinsic value	8,809,260
Range of Exercise Prices, $12.16 – $13.75 [Member] \| 2010 Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	289,750
Outstanding, weighted-average exercise price	$ 13.16
Weighted average remaining contractual life	9 years 8 months
Aggregate intrinsic value	0
Exercise price range, lower limit	$ 12.16
Exercise price range, upper limit	$ 13.75
Range of Exercise Prices, $15.04 – $16.93 [Member] \| 2010 Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	62,348
Outstanding, weighted-average exercise price	$ 15.22
Weighted average remaining contractual life	7 years 11 months
Aggregate intrinsic value	0
Range of Exercise Prices, $20.68 - $21.41 [Member] \| 2010 Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	125,624
Outstanding, weighted-average exercise price	$ 21.26
Weighted average remaining contractual life	12 years 2 months
Aggregate intrinsic value	0
Exercise price range, lower limit	$ 20.68
Exercise price range, upper limit	$ 21.41
Range of Exercise Prices, $2.35 – $3.26 [Member] \| Equity Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	292,500
Outstanding, weighted-average exercise price	$ 3.20
Weighted average remaining contractual life	4 years 0 months
Aggregate intrinsic value	1,852,825
Exercise price range, lower limit	$ 2.35
Exercise price range, upper limit	$ 3.26
Range of Exercise Prices, $3.48 – $4.90 [Member] \| Equity Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	1,007,972
Outstanding, weighted-average exercise price	$ 4.54
Weighted average remaining contractual life	3 years 0 months
Aggregate intrinsic value	5,032,901
Exercise price range, lower limit	$ 3.48
Exercise price range, upper limit	$ 4.90
Range of Exercise Prices, $5.25 – $7.18 [Member] \| Equity Plan [Member]
Share-based Compensation Details
Options exercisable (in shares)	568,125
Outstanding, weighted-average exercise price	$ 6.14
Weighted average remaining contractual life	5 years 3 months
Aggregate intrinsic value	$ 1,923,534
Exercise price range, lower limit	$ 5.25
Exercise price range, upper limit	$ 7.18

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

Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PlanNameAxis=ctg_Companys2010EquityAwardPlan2010PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=ctg_EquityPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=ctg_RangeofExercisePrices12.1613.75Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=ctg_RangeofExercisePrices15.0416.93MemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=ctg_RangeofExercisePrices2.353.26Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=ctg_RangeofExercisePrices20.6821.41Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=ctg_RangeofExercisePrices3.484.90Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=ctg_RangeofExercisePrices5.257.18Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: