Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Operating Revenues
Electric revenues	$ 2,502.2		$ 2,568.2		$ 2,446.3
Operating Expenses
Fuel	421.4		489.2		539.5
Purchased power	187.3		253.3		125.9
Transmission	89.1		74.7		53.2
Utility operating and maintenance expenses	724.8		701.9		671.4
Depreciation and amortization	330.4		306.0		289.7
General taxes	213.2		204.6		194.4
Other General and Administrative Expense	5.9		4.0		3.0
Costs and Expenses, Total	1,972.1		2,033.7		1,877.1
Operating Income (Loss)	530.1		534.5		569.2
Non-operating income	11.7		25.0		18.4
Non-operating expenses	(8.0)		(12.5)		(9.6)
Interest charges	(199.3)		(188.5)		(198.4)
Income before income tax (expense) benefit and income (loss) from equity investments	334.5		358.5		379.6
Income tax (expense) benefit	(122.7)		(115.7)		(129.2)
(Income) loss from equity investments, net of income taxes	1.2		0.0		(0.2)
Net income (loss)	213.0		242.8		250.2
Preferred stock dividend requirements	1.6		1.6		1.6
Earnings (loss) available for common shareholders	$ 211.4		$ 241.2		$ 248.6
Average number of basic common shares outstanding (in shares)	154.2		153.9		153.5
Average number of diluted common shares outstanding (in shares)	154.8		154.1		153.7
Basic and diluted earnings per common share	$ 1.37		$ 1.57		$ 1.62
Comprehensive Income
Net income (loss)	$ 213.0		$ 242.8		$ 250.2
Other comprehensive income
Reclassification to expenses, net of tax	5.7		8.0		11.6
Derivative hedging activity, net of tax	5.7		8.0		11.6
Net gain (loss) arising during period	1.0		(3.0)		2.1
Income tax (expense) benefit	(0.4)		1.2		(0.9)
Net gain (loss) arising during period, net of tax	0.6		(1.8)		1.2
Amortization of net losses included in net periodic benefit costs, net of tax	0.4		0.4		0.3
Change in unrecognized pension expense, net of tax	1.0		(1.4)		1.5
Total other comprehensive income (loss)	6.7	[1]	6.6	[1]	13.1
Comprehensive income (loss)	$ 219.7		$ 249.4		$ 263.3
Common Stock, Dividends, Per Share, Declared	$ 0.9975		$ 0.935		$ 0.8825
Kansas City Power and Light Company [Member]
Operating Revenues
Electric revenues	$ 1,713.8		$ 1,730.8		$ 1,671.4
Operating Expenses
Fuel	304.5		364.9		383.0
Purchased power	92.6		107.8		62.4
Transmission	58.4		47.2		37.3
Utility operating and maintenance expenses	494.2		489.1		475.9
Depreciation and amortization	235.7		213.9		198.3
General taxes	163.5		159.1		152.0
Other General and Administrative Expense	0.9		(1.3)		0.0
Costs and Expenses, Total	1,349.8		1,380.7		1,308.9
Operating Income (Loss)	364.0		350.1		362.5
Non-operating income	8.4		20.4		16.3
Non-operating expenses	(7.2)		(8.3)		(4.7)
Interest charges	(135.6)		(124.1)		(125.3)
Income before income tax (expense) benefit and income (loss) from equity investments	229.6		238.1		248.8
Income tax (expense) benefit	(76.8)		(75.7)		(79.8)
Net income (loss)	152.8		162.4		169.0
Comprehensive Income
Net income (loss)	152.8		162.4		169.0
Other comprehensive income
Reclassification to expenses, net of tax	5.3		5.3		5.6
Derivative hedging activity, net of tax	5.3		5.3		5.6
Total other comprehensive income (loss)	5.3		5.3		5.6
Comprehensive income (loss)	$ 158.1		$ 167.7		$ 174.6

[1] Net of tax