v3.4.0.3

Note 9 - Fuel Derivatives (Details Textual) $ in Millions	9 Months Ended
	Mar. 31, 2016 USD ($) gal
Diesel Fuel Future Contracts [Member]
Derivative, Nonmonetary Notional Amount, Volume	5,292,000
Derivative, Nonmonetary Notional Amount, Volume per Month	331,000
Derivative Nonmonetary, Percentage of Monthly Projected Fuel Requirements	10.00%
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred | $	$ (1.8)

X

- Definition

Nominal volume per month used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

Name:	cgi_DerivativeNonmonetaryNotionalAmountVolumePerMonth
Namespace Prefix:	cgi_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage of monthly projected fuel requirements entered into futures contracts.

+ References

No definition available.

+ Details

Name:	cgi_DerivativeNonmonetaryPercentageOfMonthlyProjectedFuelRequirements
Namespace Prefix:	cgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

No definition available.

+ Details

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

X

- Definition

Nominal volume used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeNonmonetaryNotionalAmountVolume
Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cgi_DieselFuelFutureContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: