Nuclear Plant (Tables)

3 Months Ended

Mar. 31, 2014

Nuclear Plant [Abstract]

Changes in nuclear decommissioning trust fund

The following table summarizes the change in Great Plains Energy's and KCP&L's nuclear decommissioning trust fund.

	March 31 2014			December 31 2013
Decommissioning Trust		(millions)
Beginning balance January 1		$	183.9		$	154.7
Contributions		0.9			3.3
Earned income, net of fees		1.1			2.7
Net realized gains		0.1			1.7
Net unrealized gains		1.4			21.5
Ending balance		$	187.4		$	183.9

Detail of assets held in nuclear decommissioning trust fund

The nuclear decommissioning trust is reported at fair value on the balance sheets and is invested in assets as detailed in the following table.

	March 31, 2014													December 31, 2013
	Cost Basis		Unrealized Gains			Unrealized Losses				Fair Value			Cost Basis			Unrealized Gains			Unrealized Losses				Fair Value
	(millions)
Equity securities	$	84.7		$	45.2		$	(0.6	)		$	129.3		$	83.7		$	44.6		$	(0.6	)		$	127.7
Debt securities	51.4			2.9			(0.3		)		54.0			51.0			2.5			(0.7		)		52.8
Other	4.1			—			—				4.1			3.4			—			—				3.4
Total	$	140.2		$	48.1		$	(0.9	)		$	187.4		$	138.1		$	47.1		$	(1.3	)		$	183.9

Gains and losses from the sale of securities by the nuclear decommissioning trust fund

The following table summarizes the realized gains and losses from the sale of securities in the nuclear decommissioning trust fund.

Three Months Ended March 31	2014			2013
	(millions)
Realized gains	$	0.2		$	1.5
Realized losses	(0.1		)	(0.4		)