Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 6,546.3	$ 1,293.1
Time deposit	0.0	1,000.0
Receivables, net	176.7	166.0
Accounts receivable pledged as collateral	172.2	172.4
Fuel inventories, at average cost	89.3	108.8
Materials and supplies, at average cost	168.5	162.2
Deferred refueling outage costs	14.2	22.3
Interest rate derivative instruments	49.2	79.3
Prepaid expenses and other assets	33.3	55.4
Total	7,249.7	3,059.5
Utility Plant, at Original Cost
Electric	13,486.5	13,597.7
Less - accumulated depreciation	5,068.4	5,106.9
Net utility plant in service	8,418.1	8,490.8
Construction work in progress	375.6	403.9
Plant to be retired, net	149.2	0.0
Nuclear fuel, net of amortization of $188.0 and $172.1	53.9	62.0
Total	8,996.8	8,956.7
Investments and Other Assets
Nuclear decommissioning trust fund	238.4	222.9
Regulatory assets	1,022.6	1,048.0
Goodwill	169.0	169.0
Other	129.9	113.9
Total	1,559.9	1,553.8
Total	17,806.4	13,570.0
Current Liabilities
Collateralized note payable	172.2	172.4
Commercial paper	424.6	334.8
Current maturities of long-term debt	482.1	382.1
Accounts payable	181.3	323.7
Accrued taxes	84.0	33.3
Accrued interest	92.7	50.8
Accrued compensation and benefits	49.0	52.1
Pension and post-retirement liability	3.0	3.0
Series B Preferred Stock dividend make-whole provisions	57.1	0.0
Other	67.5	32.6
Total	1,613.5	1,384.8
Deferred Credits and Other Liabilities
Deferred income taxes	1,314.4	1,329.7
Deferred tax credits	125.5	126.2
Asset retirement obligations	278.1	316.0
Pension and post-retirement liability	496.0	488.3
Regulatory liabilities	307.4	309.9
Other	88.9	87.9
Total	2,610.3	2,658.0
Shareholders' equity
Common stock	4,228.6	4,217.0
Preference Stock	836.2	836.2
Retained earnings	953.6	1,119.2
Treasury stock - 135,166 and 128,087 shares, at cost	(3.9)	(3.8)
Accumulated other comprehensive loss	(3.6)	(6.6)
Total shareholders' equity	6,010.9	6,162.0
Long-term debt (Note 10)	7,571.7	3,365.2
Total	13,582.6	9,527.2
Commitments and Contingencies (Note 12)
Total	17,806.4	13,570.0
Series B Preferred Stock [Member]
Current Liabilities
Series B Preferred Stock dividend make-whole provisions	57.1
Kansas City Power and Light Company [Member]
Current Assets
Cash and cash equivalents	6.0	4.5
Receivables, net	137.4	139.1
Related party receivables	70.4	67.2
Accounts receivable pledged as collateral	110.0	110.0
Fuel inventories, at average cost	63.5	72.9
Materials and supplies, at average cost	123.4	118.9
Deferred refueling outage costs	14.2	22.3
Refundable income taxes	0.0	12.7
Prepaid expenses and other assets	29.7	27.9
Total	554.6	575.5
Utility Plant, at Original Cost
Electric	10,084.6	9,925.1
Less - accumulated depreciation	3,958.9	3,858.4
Net utility plant in service	6,125.7	6,066.7
Construction work in progress	277.8	300.4
Nuclear fuel, net of amortization of $188.0 and $172.1	53.9	62.0
Total	6,457.4	6,429.1
Investments and Other Assets
Nuclear decommissioning trust fund	238.4	222.9
Regulatory assets	782.0	801.8
Other	37.2	29.1
Total	1,057.6	1,053.8
Total	8,069.6	8,058.4
Current Liabilities
Collateralized note payable	110.0	110.0
Commercial paper	171.8	132.9
Current maturities of long-term debt	381.0	281.0
Accounts payable	140.4	231.6
Accrued taxes	71.2	27.0
Accrued interest	30.8	32.4
Accrued compensation and benefits	49.0	52.1
Pension and post-retirement liability	1.6	1.6
Other	44.4	11.4
Total	1,000.2	880.0
Deferred Credits and Other Liabilities
Deferred income taxes	1,249.0	1,228.3
Deferred tax credits	122.3	122.8
Asset retirement obligations	248.9	278.0
Pension and post-retirement liability	473.7	465.8
Regulatory liabilities	197.3	187.4
Other	71.4	70.6
Total	2,362.6	2,352.9
Shareholders' equity
Common stock	1,563.1	1,563.1
Retained earnings	913.7	982.6
Accumulated other comprehensive loss	(1.6)	(4.2)
Total shareholders' equity	2,475.2	2,541.5
Long-term debt (Note 10)	2,231.6	2,284.0
Total	4,706.8	4,825.5
Commitments and Contingencies (Note 12)
Total	$ 8,069.6	$ 8,058.4