Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 1,097.9	$ 1,293.1
Time deposit	0.0	1,000.0
Receivables, net	186.4	166.0
Accounts receivable pledged as collateral	195.0	172.4
Fuel inventories, at average cost	89.2	108.8
Materials and supplies, at average cost	171.9	162.2
Deferred refueling outage costs	10.2	22.3
Refundable income taxes	1.4	0.0
Interest rate derivative instruments	77.4	79.3
Prepaid expenses and other assets	31.5	55.4
Total	1,860.9	3,059.5
Utility Plant, at Original Cost
Electric	13,552.9	13,597.7
Less - accumulated depreciation	5,149.5	5,106.9
Net utility plant in service	8,403.4	8,490.8
Construction work in progress	415.0	403.9
Plant to be retired, net	146.3	0.0
Nuclear fuel, net of amortization of $196.2 and $172.1	64.9	62.0
Total	9,029.6	8,956.7
Investments and Other Assets
Nuclear decommissioning trust fund	247.5	222.9
Regulatory assets	1,005.5	1,048.0
Goodwill	169.0	169.0
Other	116.4	113.9
Total	1,538.4	1,553.8
Total	12,428.9	13,570.0
Current Liabilities
Collateralized note payable	195.0	172.4
Commercial paper	247.9	334.8
Current maturities of long-term debt	351.1	382.1
Accounts payable	196.8	323.7
Accrued taxes	127.0	33.3
Accrued interest	57.4	50.8
Accrued compensation and benefits	51.9	52.1
Pension and post-retirement liability	3.0	3.0
Other	62.2	32.6
Total	1,292.3	1,384.8
Deferred Credits and Other Liabilities
Deferred income taxes	1,422.6	1,329.7
Deferred tax credits	125.1	126.2
Asset retirement obligations	258.5	316.0
Pension and post-retirement liability	495.3	488.3
Regulatory liabilities	310.5	309.9
Other	90.1	87.9
Total	2,702.1	2,658.0
Shareholders' equity
Common stock	4,231.1	4,217.0
Preference Stock	0.0	836.2
Retained earnings	897.6	1,119.2
Treasury stock - 136,952 and 128,087 shares, at cost	(4.0)	(3.8)
Accumulated other comprehensive loss	(2.2)	(6.6)
Total shareholders' equity	5,122.5	6,162.0
Long-term debt (Note 11)	3,312.0	3,365.2
Total	8,434.5	9,527.2
Commitments and Contingencies (Note 13)
Total	12,428.9	13,570.0
Kansas City Power and Light Company [Member]
Current Assets
Cash and cash equivalents	4.6	4.5
Receivables, net	143.8	139.1
Related party receivables	82.1	67.2
Accounts receivable pledged as collateral	130.0	110.0
Fuel inventories, at average cost	62.1	72.9
Materials and supplies, at average cost	126.1	118.9
Deferred refueling outage costs	10.2	22.3
Refundable income taxes	0.0	12.7
Prepaid expenses and other assets	26.9	27.9
Total	585.8	575.5
Utility Plant, at Original Cost
Electric	10,120.8	9,925.1
Less - accumulated depreciation	4,012.7	3,858.4
Net utility plant in service	6,108.1	6,066.7
Construction work in progress	310.8	300.4
Nuclear fuel, net of amortization of $196.2 and $172.1	64.9	62.0
Total	6,483.8	6,429.1
Investments and Other Assets
Nuclear decommissioning trust fund	247.5	222.9
Regulatory assets	761.4	801.8
Other	39.1	29.1
Total	1,048.0	1,053.8
Total	8,117.6	8,058.4
Current Liabilities
Collateralized note payable	130.0	110.0
Commercial paper	72.0	132.9
Current maturities of long-term debt	350.0	281.0
Accounts payable	154.1	231.6
Accrued taxes	137.2	27.0
Accrued interest	40.5	32.4
Accrued compensation and benefits	51.9	52.1
Pension and post-retirement liability	1.6	1.6
Other	44.0	11.4
Total	981.3	880.0
Deferred Credits and Other Liabilities
Deferred income taxes	1,266.4	1,228.3
Deferred tax credits	122.0	122.8
Asset retirement obligations	228.7	278.0
Pension and post-retirement liability	473.1	465.8
Regulatory liabilities	201.6	187.4
Other	72.3	70.6
Total	2,364.1	2,352.9
Shareholders' equity
Common stock	1,563.1	1,563.1
Retained earnings	977.8	982.6
Accumulated other comprehensive loss	(0.4)	(4.2)
Total shareholders' equity	2,540.5	2,541.5
Long-term debt (Note 11)	2,231.7	2,284.0
Total	4,772.2	4,825.5
Commitments and Contingencies (Note 13)
Total	$ 8,117.6	$ 8,058.4