Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents		$ 11.3	$ 13.0
Funds on deposit		2.1	1.2
Receivables, net		147.7	160.3
Accounts receivable pledged as collateral		175.0	171.0
Fuel inventories, at average cost		118.4	90.1
Materials and supplies, at average cost		155.7	152.7
Deferred refueling outage costs		19.2	12.5
Refundable income taxes		3.8	3.1
Deferred income taxes		0.0	78.1
Prepaid expenses and other assets		31.0	36.9
Assets, Current, Total		664.2	718.9
Utility Plant, at Original Cost
Electric	[1]	13,189.9	12,128.7
Less-accumulated depreciation		4,943.7	4,828.3
Net utility plant in service		8,246.2	7,300.4
Construction work in progress		347.9	900.0
Nuclear Fuel, Net of Amortization		68.3	79.2
Public Utilities, Property, Plant and Equipment, Net		8,662.4	8,279.6
Investments and Other Assets
Nuclear decommissioning trust fund		200.7	199.0
Regulatory Assets		979.1	1,034.6
Goodwill		169.0	169.0
Other Assets, Noncurrent		63.2	52.3
Investments and Other Assets, Total		1,412.0	1,454.9
Assets, Total		10,738.6	10,453.4
Current Liabilities
Notes payable		10.0	4.0
Collateralized note payable		175.0	171.0
Commercial paper		224.0	358.3
Current maturities of long-term debt		1.1	15.1
Accounts payable		352.9	388.0
Accrued taxes		31.6	30.4
Accrued interest		44.7	41.3
Accrued compensation and benefits		41.4	35.2
Pension and post-retirement liability		3.4	2.8
Other Liabilities, Current		31.6	24.7
Liabilities, Current, Total		915.7	1,070.8
Deferred Credits and Other Liabilities
Deferred income taxes		1,158.8	1,089.7
Deferred tax credits		125.1	126.0
Asset retirement obligations		275.9	195.9
Pension and post-retirement liability		455.2	508.6
Regulatory liabilities		284.4	282.7
Other Liabilities, Noncurrent		82.9	88.9
Liabilities, Noncurrent, Total		2,382.3	2,291.8
Common shareholders' equity
Common Stock, Value, Issued		2,646.7	2,639.3
Retained earnings		1,024.4	967.8
Treasury Stock, Value		(2.6)	(2.3)
Accumulated other comprehensive loss	[2]	(12.0)	(18.7)
Common Shareholders' Equity, Total		3,656.5	3,586.1
Cumulative preferred stock $100 par value
Preferred Stock, Value, Issued		39.0	39.0
Long-term debt	[3]	3,745.1	3,465.7
Total Capitalization		$ 7,440.6	$ 7,090.8
Commitments and Contingencies
Liabilities and Equity, Total		$ 10,738.6	$ 10,453.4
Preferred Stock 3 Point 80 [Member]
Cumulative preferred stock $100 par value
Preferred Stock, Value, Issued		10.0	10.0
Preferred Stock 4 Point 50 [Member]
Cumulative preferred stock $100 par value
Preferred Stock, Value, Issued		10.0	10.0
Preferred Stock 4 Point 20 [Member]
Cumulative preferred stock $100 par value
Preferred Stock, Value, Issued		7.0	7.0
Preferred Stock 4 Point 35 [Member]
Cumulative preferred stock $100 par value
Preferred Stock, Value, Issued		12.0	12.0
Kansas City Power and Light Company [Member]
Current Assets
Cash and cash equivalents		2.3	2.7
Funds on deposit		0.5	0.6
Receivables, net		129.2	128.9
Related party receivables		65.8	68.8
Accounts receivable pledged as collateral		110.0	110.0
Fuel inventories, at average cost		83.5	58.8
Materials and supplies, at average cost		114.6	110.1
Deferred refueling outage costs		19.2	12.5
Refundable income taxes		79.0	57.5
Deferred income taxes		0.0	5.0
Prepaid expenses and other assets		27.1	32.7
Assets, Current, Total		631.2	587.6
Utility Plant, at Original Cost
Electric	[4]	9,640.4	8,737.3
Less-accumulated depreciation		3,722.6	3,658.7
Net utility plant in service		5,917.8	5,078.6
Construction work in progress		246.6	791.2
Nuclear Fuel, Net of Amortization		68.3	79.2
Public Utilities, Property, Plant and Equipment, Net		6,232.7	5,949.0
Investments and Other Assets
Nuclear decommissioning trust fund		200.7	199.0
Regulatory Assets		732.4	745.7
Other Assets, Noncurrent		17.6	13.8
Investments and Other Assets, Total		950.7	958.5
Assets, Total		7,814.6	7,495.1
Current Liabilities
Collateralized note payable		110.0	110.0
Commercial paper		180.3	358.3
Current maturities of long-term debt		0.0	14.0
Accounts payable		258.8	305.2
Related party payables		0.0	12.6
Accrued taxes		25.6	23.6
Accrued interest		32.4	29.0
Accrued compensation and benefits		41.4	35.2
Pension and post-retirement liability		2.0	1.5
Other Liabilities, Current		12.6	12.4
Liabilities, Current, Total		663.1	901.8
Deferred Credits and Other Liabilities
Deferred income taxes		1,132.6	1,016.9
Deferred tax credits		123.8	124.3
Asset retirement obligations		239.3	177.7
Pension and post-retirement liability		433.4	485.4
Regulatory liabilities		164.6	172.0
Other Liabilities, Noncurrent		61.6	59.2
Liabilities, Noncurrent, Total		2,155.3	2,035.5
Common shareholders' equity
Common Stock, Value, Issued		1,563.1	1,563.1
Retained earnings		879.6	726.8
Accumulated other comprehensive loss		(9.6)	(14.9)
Common Shareholders' Equity, Total		2,433.1	2,275.0
Cumulative preferred stock $100 par value
Long-term debt	[3]	2,563.1	2,282.8
Total Capitalization		$ 4,996.2	$ 4,557.8
Commitments and Contingencies
Liabilities and Equity, Total		$ 7,814.6	$ 7,495.1

[1] Includes $214.0 million and $127.9 million at December 31, 2015 and 2014, respectively, of land and other assets that are not depreciated.

[2] Net of tax

[3] At December 31, 2015, does not include $50.0 million and $21.9 million of secured Series 2005 Environmental Improvement Revenue Refunding (EIRR) bonds because the bonds were repurchased in September 2015 and are held by KCP&L.

[4] Includes $136.5 million and $72.4 million at December 31, 2015 and 2014, respectively, of land and other assets that are not depreciated.