Fair Value Measurements (Tables)

6 Months Ended

Jun. 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 at June 30, 2013, and December 31, 2012.

								Fair Value Measurements Using
Description	June 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
Derivative instruments(a)		$	0.3		$	—			$	0.3		$	—		$	—
Nuclear decommissioning trust (b)
Equity securities		109.9			—				109.9			—			—
Debt securities
U.S. Treasury		19.1			—				19.1			—			—
U.S. Agency		2.4			—				—			2.4			—
State and local obligations		3.1			—				—			3.1			—
Corporate bonds		24.5			—				—			24.5			—
Other		1.0			—				—			1.0			—
Total nuclear decommissioning trust		160.0			—				129.0			31.0			—
Total		$	160.3		$	—			$	129.3		$	31.0		$	—
Other Great Plains Energy
Assets
Derivative instruments (a)		$	6.2		$	(0.1	)		$	—		$	4.4		$	1.9
SERP rabbi trusts (c)
Equity securities		0.1			—				0.1			—			—
Fixed income funds		19.7			—				—			19.7			—
Total SERP rabbi trusts		19.8			—				0.1			19.7			—
Total		26.0			(0.1		)		0.1			24.1			1.9
Liabilities
Derivative instruments (a)		—			(1.2		)		1.2			—			—
Total		$	—		$	(1.2	)		$	1.2		$	—		$	—
Great Plains Energy
Assets
Derivative instruments (a)		$	6.5		$	(0.1	)		$	0.3		$	4.4		$	1.9
Nuclear decommissioning trust (b)		160.0			—				129.0			31.0			—
SERP rabbi trusts (c)		19.8			—				0.1			19.7			—
Total		186.3			(0.1		)		129.4			55.1			1.9
Liabilities
Derivative instruments (a)		—			(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 (b)
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 (a)		—			(0.2		)		0.2			—			—
Total		$	—		$	(0.2	)		$	0.2		$	—		$	—
Other Great Plains Energy
Assets
Derivative instruments (a)		$	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 (a)		—			(2.8		)		2.8			—			—
Total		$	—		$	(2.8	)		$	2.8		$	—		$	—
Great Plains Energy
Assets
Derivative instruments (a)		$	6.5		$	—			$	—		$	4.2		$	2.3
Nuclear decommissioning trust (b)		151.8			—				118.6			33.2			—
SERP rabbi trusts (c)		20.3			—				0.1			20.2			—
Total		178.6			—				118.7			57.6			2.3
Liabilities
Derivative instruments (a)		—			(3.0		)		3.0			—			—
Total		$	—		$	(3.0	)		$	3.0		$	—		$	—

^(a)  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.    

^(b)  Fair value is based on quoted market prices of the investments held by the fund and/or valuation models.  The total does not include $4.7 million and $2.9 million at June 30, 2013, and December 31, 2012, respectively, of cash and cash equivalents, which are not subject to the fair value requirements.

^(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. The total does not include $0.1 million at June 30, 2013, and December 31, 2012, of cash and cash equivalents, which are not subject to the fair value requirements.

^(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 June 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 and liabilities, net, measured at fair value on a recurring basis for the three months ended and year to date June 30, 2013 and 2012.

Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative Instruments
	2013			2012
	(millions)
Balance at April 1	$	2.4		$	2.4
Total realized/unrealized gains included in non-operating income	1.9			0.9
Settlements	(2.4		)	(1.1		)
Balance at June 30	$	1.9		$	2.2
Total unrealized losses included in non-operating income relating to assets
and liabilities still on the consolidated balance sheet at June 30	$	(0.3	)	$	(0.1	)

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	4.3			1.1
Settlements	(4.7		)	(2.0		)
Balance at June 30	$	1.9		$	2.2
Total unrealized losses included in non-operating income relating to assets
and liabilities still on the consolidated balance sheet at June 30	$	(0.1	)	$	(0.7	)