Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2013

Fair Value Disclosures [Abstract]

Fair value of assets and liabilities

The following tables include Great Plains Energy's and KCP&L's balances of financial assets and liabilities measured at fair value on a recurring basis.

									Fair Value Measurements Using
Description	September 30 2013				Netting(d)				Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)
KCP&L		(millions)
Assets
Nuclear decommissioning trust (a)
Equity securities		$	117.5			$	—			$	117.5		$	—			$	—
Debt securities
U.S. Treasury		20.8				—				20.8			—				—
U.S. Agency		2.4				—				—			2.4				—
State and local obligations		3.2				—				—			3.2				—
Corporate bonds		25.1				—				—			25.1				—
Foreign governments		0.6				—				—			0.6				—
Cash equivalents		5.3				—				—			5.3				—
Other		(2.1		)		—				—			(2.1		)		—
Total nuclear decommissioning trust		172.8				—				138.3			34.5				—
Total		$	172.8			$	—			$	138.3		$	34.5			$	—
Other Great Plains Energy
Assets
Derivative instruments (b)		$	5.9			$	(0.1	)		$	—		$	4.4			$	1.6
SERP rabbi trusts (c)
Equity securities		0.1				—				0.1			—				—
Fixed income funds		18.7				—				—			18.7				—
Total SERP rabbi trusts		18.8				—				0.1			18.7				—
Total		24.7				(0.1		)		0.1			23.1				1.6
Liabilities
Derivative instruments (b)		—				(1.2		)		1.2			—				—
Total		$	—			$	(1.2	)		$	1.2		$	—			$	—
Great Plains Energy
Assets
Nuclear decommissioning trust (a)		$	172.8			$	—			$	138.3		$	34.5			$	—
Derivative instruments (b)		5.9				(0.1		)		—			4.4				1.6
SERP rabbi trusts (c)		18.8				—				0.1			18.7				—
Total		197.5				(0.1		)		138.4			57.6				1.6
Liabilities
Derivative instruments (b)		—				(1.2		)		1.2			—				—
Total		$	—			$	(1.2	)		$	1.2		$	—			$	—

								Fair Value Measurements Using
Description	December 31 2012			Netting(d)				Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
KCP&L		(millions)
Assets
Nuclear decommissioning trust (a)
Equity securities		$	100.1		$	—			$	100.1		$	—		$	—
Debt securities
U.S. Treasury		18.5			—				18.5			—			—
U.S. Agency		2.8			—				—			2.8			—
State and local obligations		3.3			—				—			3.3			—
Corporate bonds		26.8			—				—			26.8			—
Other		0.3			—				—			0.3			—
Total nuclear decommissioning trust		151.8			—				118.6			33.2			—
Total		151.8			—				118.6			33.2			—
Liabilities
Derivative instruments (b)		—			(0.2		)		0.2			—			—
Total		$	—		$	(0.2	)		$	0.2		$	—		$	—
Other Great Plains Energy
Assets
Derivative instruments (b)		$	6.5		$	—			$	—		$	4.2		$	2.3
SERP rabbi trusts (c)
Equity securities		0.1			—				0.1			—			—
Fixed income funds		20.2			—				—			20.2			—
Total SERP rabbi trusts		20.3			—				0.1			20.2			—
Total		26.8			—				0.1			24.4			2.3
Liabilities
Derivative instruments (b)		—			(2.8		)		2.8			—			—
Total		$	—		$	(2.8	)		$	2.8		$	—		$	—
Great Plains Energy
Assets
Nuclear decommissioning trust (a)		$	151.8		$	—			$	118.6		$	33.2		$	—
Derivative instruments (b)		6.5			—				—			4.2			2.3
SERP rabbi trusts (c)		20.3			—				0.1			20.2			—
Total		178.6			—				118.7			57.6			2.3
Liabilities
Derivative instruments (b)		—			(3.0		)		3.0			—			—
Total		$	—		$	(3.0	)		$	3.0		$	—		$	—

^(a)  Fair value is based on quoted market prices of the investments held by the fund and/or valuation models.  The total does not include $2.9 million of cash and cash equivalents at December 31, 2012.

^(b)  The fair value of derivative instruments is estimated using market quotes, over-the-counter forward price and volatility curves and correlations among fuel prices, net of estimated credit risk. Derivative instruments classified as Level 1 represent exchange traded derivative instruments. Derivative instruments classified as Level 2 represent non-exchange traded derivative instruments traded in over-the-counter markets. Derivative instruments classified as Level 3 represent non-exchange traded derivatives traded in over-the-counter markets for which observable market data is not available to corroborate the valuation inputs.

^(c)  Fair value is based on quoted market prices and/or valuation models for equity securities and Net Asset Value (NAV) per share for fixed income funds.

^(d)  Represents the difference between derivative contracts in an asset or liability position presented on a net basis by counterparty on the consolidated balance sheets where a master netting agreement exists between the Company and the counterparty. At September 30, 2013, and December 31, 2012, Great Plains Energy netted $1.1 million and $3.0 million, respectively, of cash collateral posted with counterparties.

Unobservable inputs reconciliation

The following tables reconcile the beginning and ending balances for all Level 3 assets measured at fair value on a recurring basis.

Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative Instruments
	2013			2012
	(millions)
Balance at July 1	$	1.9		$	2.2
Total realized/unrealized gains included in non-operating income	1.0			3.7
Settlements	(1.3		)	(3.5		)
Balance at September 30	$	1.6		$	2.4
Total unrealized gains (losses) included in non-operating income relating to assets
still on the consolidated balance sheet at September 30	$	(0.3	)	$	0.3

Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative Instruments
	2013			2012
	(millions)
Balance at January 1	$	2.3		$	3.1
Total realized/unrealized gains included in non-operating income	5.3			4.8
Settlements	(6.0		)	(5.5		)
Balance at September 30	$	1.6		$	2.4
Total unrealized losses included in non-operating income relating to assets
still on the consolidated balance sheet at September 30	$	(0.4	)	$	(0.4	)