Represents the contracted capacity (in megawatts) from a variable interest entity under a power purchase agreement.

No definition available.

Name:	teg_ContractedCapacityFromVariableInterestEntity
Namespace Prefix:	teg_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the cash paid for the early termination of an existing contract.

+ References

No definition available.

+ Details

Name:	teg_ContractTerminationCosts
Namespace Prefix:	teg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the obligations to purchase energy (in megawatts) from a variable interest entity under a power purchase agreement.

+ References

No definition available.

+ Details

Name:	teg_ObligationsToPurchaseEnergyUnderPowerPurchaseAgreement
Namespace Prefix:	teg_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	teg_VariableInterestEntitiesDisclosureAbstract
Namespace Prefix:	teg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 5A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7880789&loc=SL6759159-111685

+ Details

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

VARIABLE INTEREST ENTITIES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013 MW	Mar. 31, 2013 WPS Fox Energy Company, LLC MW	Dec. 31, 2012 AMP Trillium LLC	Dec. 31, 2012 AMP Trillium LLC AMP Americas LLC	Dec. 31, 2011 PTI CNG Fuels LLC
VARIABLE INTEREST ENTITIES
Obligations to purchase energy under power purchase agreement (in megawatts)	0
Contracted capacity under a power purchase agreement (in megawatts)	17.5	500
Variable Interest Entity
Contract termination fee related to tolling arrangement	$ (50.0)	$ 50.0
Variable interest entity ownership interest acquired (as a percent)			30.00%	70.00%	50.00%
Contracted capacity under a power purchase agreement (in megawatts)	17.5	500