Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2016

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Values of open positions for derivative instruments [Table Text Block]

The gross notional contract amount and recorded fair values of open positions for derivative instruments are summarized in the following table.  The fair values of these derivatives are recorded on the consolidated balance sheets.  The fair values below are gross values before netting agreements and netting of cash collateral.

	September 30					December 31
	2016					2015
	Notional Contract Amount		Fair Value			Notional Contract Amount		Fair Value
Great Plains Energy	(millions)
Non-hedging derivatives
Futures contracts	$	14.9	$	—		$	26.6	$	(5.7	)
Forward contracts	11.1		2.6			15.6		3.1
Transmission congestion rights	5.1		0.7			5.6		(0.5		)
Interest rate swaps	4,415.0		(78.8		)	—		—
KCP&L
Non-hedging derivatives
Futures contracts	$	0.2	$	—		$	0.9	$	(0.1	)
Transmission congestion rights	3.9		0.4			4.1		(0.4		)

Fair value of open derivative positions, gross values before netting agreements and netting of cash collateral [Table Text Block]

The fair values of Great Plains Energy's and KCP&L's open derivative positions and balance sheet classification are summarized in the following tables. The fair values below are gross values before netting agreements and netting of cash collateral.

Great Plains Energy
	Balance Sheet	Asset Derivatives			Liability Derivatives
September 30, 2016	Classification	Fair Value			Fair Value
Derivatives Not Designated as Hedging Instruments			(millions)
Commodity contracts	Other		$	5.3		$	2.0
Interest rate contracts	Derivative instruments		—			78.8
December 31, 2015
Derivatives Not Designated as Hedging Instruments
Commodity contracts	Other/Derivative instruments		$	3.3		$	6.4

KCP&L
	Balance Sheet	Asset Derivatives			Liability Derivatives
September 30, 2016	Classification	Fair Value			Fair Value
Derivatives Not Designated as Hedging Instruments			(millions)
Commodity contracts	Other		$	1.1		$	0.7
December 31, 2015
Derivatives Not Designated as Hedging Instruments
Commodity contracts	Other		$	0.2		$	0.7

Offsetting Derivative Assets and Liabilities [Table Text Block]

The following tables provide information regarding Great Plains Energy's and KCP&L's offsetting of derivative assets and liabilities.

Great Plains Energy
											Gross Amounts Not Offset in the Statement of Financial Position
Description	Gross Amounts Recognized			Gross Amounts Offset in the Statement of Financial Position				Net Amounts Presented in the Statement of Financial Position			Financial Instruments			Cash Collateral			Net Amount
September 30, 2016	(millions)
Derivative assets		$	5.3		$	(2.0	)		$	3.3		$	—		$	—		$	3.3
Derivative liabilities		80.8			(2.0		)		78.8			—			—			78.8
December 31, 2015
Derivative assets		$	3.3		$	(0.2	)		$	3.1		$	—		$	—		$	3.1
Derivative liabilities		6.4			(5.9		)		0.5			—			—			0.5

KCP&L
											Gross Amounts Not Offset in the Statement of Financial Position
Description	Gross Amounts Recognized			Gross Amounts Offset in the Statement of Financial Position				Net Amounts Presented in the Statement of Financial Position			Financial Instruments			Cash Collateral			Net Amount
September 30, 2016	(millions)
Derivative assets		$	1.1		$	(0.7	)		$	0.4		$	—		$	—		$	0.4
Derivative liabilities		0.7			(0.7		)		—			—			—			—
December 31, 2015
Derivative assets		$	0.2		$	(0.2	)		$	—		$	—		$	—		$	—
Derivative liabilities		0.7			(0.3		)		0.4			—			—			0.4

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]

The following tables summarize the amounts of gain (loss) recognized for the change in fair value of derivatives not designated as hedging instruments for Great Plains Energy and KCP&L.

Great Plains Energy
	Three Months Ended  September 30						Year to Date September 30
Derivatives Not Designated as Hedging Instruments	2016			2015			2016			2015
Location of Gain (Loss)	(millions)
Electric revenues	$	2.0		$	(0.2	)	$	1.7		$	(7.9	)
Fuel	(0.1		)	(0.1		)	(4.6		)	(1.2		)
Purchased power	0.5			(0.2		)	0.2			(1.4		)
Interest charges	(1.8		)	—			(78.8		)	—
Regulatory asset	—			(1.9		)	(0.1		)	(5.1		)
Regulatory liability	(0.3		)	—			0.9			—
Total	$	0.3		$	(2.4	)	$	(80.7	)	$	(15.6	)

KCP&L
	Three Months Ended  September 30					Year to Date September 30
Derivatives Not Designated as Hedging Instruments	2016		2015			2016		2015
Location of Gain (Loss)	(millions)
Electric revenues	$	2.0	$	(0.2	)	$	1.7	$	(7.9	)
Fuel	0.3		1.1			0.2		1.3
Regulatory asset	0.1		(0.1		)	—		(0.1		)
Regulatory liability	—		—			0.5		—
Total	$	2.4	$	0.8		$	2.4	$	(6.7	)