A data point concentration of the interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

No definition available.

+ Details

Name:	cigi_FairValueInputsDiscountRateDataPointConcentration
Namespace Prefix:	cigi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Increase in the weighted average interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

No definition available.

+ Details

Name:	cigi_FairValueInputsWeightedAverageDiscountRateIncrease
Namespace Prefix:	cigi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

+ Details

Name:	cigi_Note19FinancialInstrumentsDetailsLineItems
Namespace Prefix:	cigi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of contingent consideration liability reduced by increase in the weighted average discount rate.

+ References

No definition available.

+ Details

Name:	cigi_ReductionInFairValueOfContingentConsiderationLiability
Namespace Prefix:	cigi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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

- Details

Name:	us-gaap_EligibleItemOrGroupForFairValueOptionAxis=cigi_ContingentConsiderationLiabilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_EligibleItemOrGroupForFairValueOptionAxis=cigi_FairValuesForOtherFinancialInstrumentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_WeightedAverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 19 - Financial Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Contingent Consideration Liability [Member]
Note 19 - Financial Instruments (Details) [Line Items]
Fair Value Inputs, Weighted Average Discount Rate, Increase	2.00%
Reduction in Fair Value of Contingent Consideration Liability (in Dollars)	$ 1,300
Minimum [Member] \| Contingent Consideration Liability [Member]
Note 19 - Financial Instruments (Details) [Line Items]
Fair Value Inputs, Discount Rate	4.00%
Fair Value Inputs, Discount Rate, Data Point Concentration	9.40%
Minimum [Member] \| Fair Values For Other Financial Instruments [Member]
Note 19 - Financial Instruments (Details) [Line Items]
Fair Value Inputs, Discount Rate		0.10%
Maximum [Member] \| Contingent Consideration Liability [Member]
Note 19 - Financial Instruments (Details) [Line Items]
Fair Value Inputs, Discount Rate	10.10%
Fair Value Inputs, Discount Rate, Data Point Concentration	10.10%
Maximum [Member] \| Fair Values For Other Financial Instruments [Member]
Note 19 - Financial Instruments (Details) [Line Items]
Fair Value Inputs, Discount Rate		2.20%
Weighted Average [Member] \| Contingent Consideration Liability [Member]
Note 19 - Financial Instruments (Details) [Line Items]
Fair Value Inputs, Discount Rate	8.90%