LEGAL PROCEEDINGS (Details) (USD $) In Millions	Sep. 30, 2011
Kansas City Power and Light Company [Member] \| Spent Nuclear Fuel and Radioactive Waste [Member]
Loss Contingencies [Line Items]
Amount of pending claims against the United States in the U.S. Court	$ 14.1
Amount awarded but subject to appeal	5.0
KCPL Greater Missouri Operations Company [Member] \| Price Reporting Litigation [Member]
Loss Contingencies [Line Items]
Approximate amount of refunds received as a net purchaser of power through settlements with sellers of power	8.0
Estimated additional refunds entitled to receive	12.0
Amount of claims addressed under refund proceedings	5.1
Total Wolf Creek including KCPL [Member] \| Pending or Threatened Litigation [Member]
Loss Contingencies [Line Items]
Amount awarded but subject to appeal	$ 10.6

Pertains to the amount awarded to Kansas City Power and Light Company by the U.S. Court of Federal for damages from the government's failure to begin accepting spent nuclear fuel for disposal as required by the Nuclear Waste Policy Act of 1982. All amounts are subject to appeal.

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- Definition

Claims against MPS Merchant Services, Inc. for the period between December 25, 2000 and June 20, 2001 related to the potential impact of California market issues on buyers in the Pacific Northwest.

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- Definition

Pertains to the amount of pending claims filed by Kansas City Power and Light Company against the United States in the U.S. Court of Federal for damages from government's failure to begin accepting spent nuclear fuel for disposal as required by the Nuclear Waste Policy Act of 1982.

+ Details

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- Definition

The approximate amount of refunds received by MPS Merchant Services, Inc., a wholly owned subsidiary of KCPL Greater Missouri Operations Company, for net purchases of power in the California energy markets between October 2, 2000 through June 20, 2001.

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- Definition

The approximate amount of additional refunds MPS Merchant Services, Inc. estimates it is entitled to for net purchases of power in the California energy markets between October 2, 2000 through June 20, 2001.

+ Details

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- 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.

+ Details

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