Ipalco Enterprises 8-K 12 May 16 2015 FY Other Events Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Feb. 23, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,015
Entity Registrant Name	IPALCO ENTERPRISES, INC.
Entity Central Index Key	728,391
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		101,504,105
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Public Float			$ 0

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
UTILITY OPERATING REVENUES	$ 1,250,399	$ 1,321,674	$ 1,255,734
UTILITY OPERATING EXPENSES:
Fuel	315,600	411,217	376,450
Other operating expenses	224,282	218,932	235,082
Power purchased	145,064	116,648	94,265
Maintenance	131,574	113,248	112,913
Depreciation and amortization	188,267	185,263	182,305
Taxes other than income taxes	43,617	45,218	45,425
Income taxes - net	57,284	70,235	58,548
Total utility operating expenses	1,105,688	1,160,761	1,104,988
UTILITY OPERATING INCOME	144,711	160,913	150,746
OTHER INCOME AND (DEDUCTIONS):
Allowance for equity funds used during construction	15,302	7,381	4,331
Loss on early extinguishment of debt	(21,956)	0	(35)
Miscellaneous income and (deductions) - net	(2,994)	(2,236)	(2,845)
Income tax benefit applicable to nonoperating income	25,718	22,191	20,806
Total other income and (deductions) - net	16,070	27,336	22,257
INTEREST AND OTHER CHARGES:
Interest on long-term debt	106,936	108,104	104,602
Other interest	2,063	1,865	1,794
Allowance for borrowed funds used during construction	(12,809)	(4,963)	(2,517)
Amortization of redemption premiums and expense on debt	5,067	5,275	5,075
Total interest and other charges - net	101,257	110,281	108,954
NET INCOME	59,524	77,968	64,049
LESS: PREFERRED DIVIDENDS OF SUBSIDIARY	3,213	3,213	3,213
NET INCOME APPLICABLE TO COMMON STOCK	56,311	74,755	60,836
Indianapolis Power And Light Company [Member]
UTILITY OPERATING REVENUES	1,250,399	1,321,674	1,255,734
UTILITY OPERATING EXPENSES:
Fuel	315,600	411,217	376,450
Other operating expenses	224,282	218,932	235,082
Power purchased	145,064	116,648	94,265
Maintenance	131,574	113,248	112,913
Depreciation and amortization	188,267	185,263	182,305
Taxes other than income taxes	43,617	45,218	45,425
Income taxes - net	57,284	70,235	58,548
Total utility operating expenses	1,105,688	1,160,761	1,104,988
UTILITY OPERATING INCOME	144,711	160,913	150,746
OTHER INCOME AND (DEDUCTIONS):
Allowance for equity funds used during construction	15,302	7,381	4,331
Miscellaneous income and (deductions) - net	(2,019)	(1,203)	(1,981)
Income tax benefit applicable to nonoperating income	1,066	953	828
Total other income and (deductions) - net	14,349	7,131	3,178
INTEREST AND OTHER CHARGES:
Interest on long-term debt	65,277	59,104	55,602
Other interest	2,063	1,865	1,794
Allowance for borrowed funds used during construction	(12,809)	(4,963)	(2,517)
Amortization of redemption premiums and expense on debt	2,608	2,510	2,493
Total interest and other charges - net	57,139	58,516	57,372
NET INCOME	101,921	109,528	96,552
LESS: PREFERRED DIVIDENDS OF SUBSIDIARY	3,213	3,213	3,213
NET INCOME APPLICABLE TO COMMON STOCK	$ 98,708	$ 106,315	$ 93,339

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
UTILITY PLANT:
Utility plant in service	$ 4,992,594	$ 4,658,023
Less accumulated depreciation	2,320,955	2,264,606
Utility plant in service - net	2,671,639	2,393,417
Construction work in progress	766,406	447,399
Spare parts inventory	12,336	14,816
Property held for future use	1,002	1,002
Utility plant - net	3,451,383	2,856,634
OTHER ASSETS:
Nonutility property - at cost, less accumulated depreciation	517	522
Other long-term assets	5,664	6,221
Other assets - net	6,181	6,743
CURRENT ASSETS:
Cash and cash equivalents	21,521	26,933
Accounts receivable and unbilled revenue (less allowance for doubtful accounts of $2,076 and $1,982, respectively)	124,167	139,709
Fuel inventories - at average cost	66,834	47,550
Materials and supplies - at average cost	57,997	60,185
Deferred tax asset - current	0	61,782
Regulatory assets	8,002	93
Prepayments and other current assets	26,063	23,161
Total current assets	304,584	359,413
DEFERRED DEBITS:
Regulatory assets	448,200	419,193
Miscellaneous	6,821	10,539
Total deferred debits	455,021	429,732
TOTAL	4,217,169	3,652,522
Common shareholders' equity:
Paid in capital	383,448	168,610
Accumulated deficit	(30,515)	(17,339)
Total common shareholders' equity	352,933	151,271
Cumulative preferred stock of subsidiary	59,784	59,784
Long-term debt	2,153,276	1,935,717
Total capitalization	2,565,993	2,146,772
CURRENT LIABILITIES:
Short-term debt	166,655	50,000
Accounts payable	155,428	110,623
Accrued expenses	19,482	25,187
Accrued real estate and personal property taxes	17,712	19,177
Regulatory liabilities	28,169	27,943
Accrued interest	31,690	30,726
Customer deposits	30,719	28,337
Other current liabilities	12,623	12,881
Total current liabilities	462,478	304,874
DEFERRED CREDITS AND OTHER LONG-TERM LIABILITIES:
Regulatory liabilities	639,516	610,917
Deferred income taxes - net	397,394	421,127
Non-current income tax liability	7,147	7,042
Unamortized investment tax credit	3,910	5,229
Accrued pension and other postretirement benefits	80,734	96,464
Asset retirement obligations	58,986	59,098
Miscellaneous	1,011	999
Total deferred credits and other long-term liabilities	$ 1,188,698	$ 1,200,876
COMMITMENTS AND CONTINGENCIES
TOTAL	$ 4,217,169	$ 3,652,522
Indianapolis Power And Light Company [Member]
UTILITY PLANT:
Utility plant in service	4,992,594	4,658,023
Less accumulated depreciation	2,320,955	2,264,606
Utility plant in service - net	2,671,639	2,393,417
Construction work in progress	766,406	447,399
Spare parts inventory	12,336	14,816
Property held for future use	1,002	1,002
Utility plant - net	3,451,383	2,856,634
OTHER ASSETS:
Other assets - net	947	1,648
CURRENT ASSETS:
Cash and cash equivalents	19,852	20,999
Accounts receivable and unbilled revenue (less allowance for doubtful accounts of $2,076 and $1,982, respectively)	124,167	139,709
Fuel inventories - at average cost	66,834	47,550
Materials and supplies - at average cost	57,998	60,185
Deferred tax asset - current	0	41,551
Regulatory assets	8,002	93
Prepayments and other current assets	28,578	23,031
Total current assets	305,431	333,118
DEFERRED DEBITS:
Regulatory assets	448,200	419,193
Miscellaneous	6,819	10,551
Total deferred debits	455,019	429,744
TOTAL	4,212,780	3,621,144
Common shareholders' equity:
Common stock	324,537	324,537
Paid in capital	385,140	170,306
Accumulated deficit	415,227	430,266
Total common shareholders' equity	1,124,904	925,109
Cumulative preferred stock of subsidiary	59,784	59,784
Long-term debt	1,355,505	1,141,627
Total capitalization	2,540,193	2,126,520
CURRENT LIABILITIES:
Short-term debt	166,655	50,000
Accounts payable	155,411	110,606
Accrued expenses	19,466	25,084
Accrued real estate and personal property taxes	17,712	19,177
Regulatory liabilities	28,169	27,943
Accrued interest	21,104	20,108
Customer deposits	30,719	28,337
Other current liabilities	22,323	12,581
Total current liabilities	461,559	293,836
DEFERRED CREDITS AND OTHER LONG-TERM LIABILITIES:
Regulatory liabilities	639,516	610,917
Deferred income taxes - net	419,731	421,044
Non-current income tax liability	7,147	7,042
Unamortized investment tax credit	3,910	5,229
Accrued pension and other postretirement benefits	80,734	96,464
Asset retirement obligations	58,986	59,098
Miscellaneous	1,004	994
Total deferred credits and other long-term liabilities	$ 1,211,028	$ 1,200,788
COMMITMENTS AND CONTINGENCIES
TOTAL	$ 4,212,780	$ 3,621,144

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts receivable and unbilled revenue, allowance for doubtful accounts	$ 2,498	$ 2,076
Indianapolis Power And Light Company [Member]
Accounts receivable and unbilled revenue, allowance for doubtful accounts	$ 2,498	$ 2,076

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 59,524	$ 77,968	$ 64,049
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	201,475	188,477	182,663
(Deferral) amortization of regulatory assets	(8,731)	1,123	3,686
Amortization of debt premium	596	942	865
Deferred income taxes and investment tax credit adjustments - net	31,566	47,455	(10,284)
Loss on early extinguishment of debt	21,956	0	377
Allowance for equity funds used during construction	(14,996)	(7,136)	(4,088)
Gain on sale of nonutility property	0	0	(297)
Change in certain assets and liabilities:
Accounts receivable	15,542	3,699	(1,900)
Fuel, materials and supplies	(18,372)	5,094	(10,337)
Income taxes receivable or payable	0	590	3,026
Financial transmission rights	2,086	(1,947)	(1,869)
Accounts payable and accrued expenses	(716)	(24,322)	16,124
Accrued real estate and personal property taxes	(1,465)	(47)	(181)
Accrued interest	965	1,034	(2,288)
Pension and other postretirement benefit expenses	(15,730)	2,785	(180,337)
Short-term and long-term regulatory assets and liabilities	(22,980)	(44,252)	148,169
Prepaids and other current assets	(4,949)	1,725	(2,986)
Other - net	6,654	809	6,983
Net cash provided by operating activities	252,425	253,997	211,375
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures - utility	(672,849)	(381,626)	(242,124)
Project development costs	(8,980)	(9,657)	(6,047)
Proceeds from the sales of assets	0	0	225
Grants under the American Recovery and Reinvestment Act of 2009	0	0	923
Cost of removal, net of salvage	(12,064)	(6,036)	(7,553)
Other	(1,224)	(39)	57
Net cash used in investing activities	(695,117)	(397,358)	(254,519)
CASH FLOWS FROM FINANCING ACTIVITIES:
Short-term debt borrowings	388,850	105,000	150,500
Short-term debt repayments	(272,000)	(105,000)	(150,500)
Long-term borrowings, net of discount	753,350	128,358	169,728
Retirement of long-term debt and early tender premium	(552,179)	0	(110,377)
Dividends on common stock	(69,487)	(78,400)	(59,500)
Issuance of common stock	214,366	0	0
Equity contributions from AES	0	106,400	49,091
Dividends on preferred stock	(3,213)	(3,213)	(3,213)
Deferred financing costs paid	(8,824)	(1,724)	(1,996)
Payments for financed capital expenditures	(13,215)	0	0
Other	(368)	(194)	(9)
Net cash provided by financing activities	437,280	151,227	43,724
Net change in cash and cash equivalents	(5,412)	7,866	580
Cash and cash equivalents at beginning of period	26,933	19,067	18,487
Cash and cash equivalents at end of period	21,521	26,933	19,067
Cash paid during the period for:
Interest (net of amount capitalized)	95,137	103,938	106,175
Income taxes	0	0	45,000
Non-cash investing activities:
Accruals for capital expenditures	79,553	37,293	17,957
Indianapolis Power And Light Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	101,921	109,528	96,552
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	199,551	186,614	180,917
(Deferral) amortization of regulatory assets	(8,731)	1,123	3,686
Amortization of debt premium	60	40	30
Deferred income taxes and investment tax credit adjustments - net	33,756	67,831	(10,594)
Allowance for equity funds used during construction	(14,996)	(7,136)	(4,088)
Gain on sale of nonutility property	0	0	(297)
Change in certain assets and liabilities:
Accounts receivable	15,542	3,699	(1,900)
Fuel, materials and supplies	(18,372)	5,094	(10,337)
Income taxes receivable or payable	(2,544)	1,171	3,510
Financial transmission rights	2,086	(1,947)	(1,869)
Accounts payable and accrued expenses	(356)	(23,723)	16,290
Accrued real estate and personal property taxes	(1,465)	(47)	(181)
Accrued interest	996	1,034	(2,288)
Pension and other postretirement benefit expenses	(15,730)	2,785	(180,338)
Short-term and long-term regulatory assets and liabilities	(22,980)	(44,252)	148,169
Prepaids and other current assets	(4,671)	(170)	(2,917)
Other - net	5,895	2,385	7,195
Net cash provided by operating activities	269,962	304,029	241,540
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures - utility	(672,849)	(381,626)	(242,124)
Project development costs	(8,980)	(9,657)	(6,047)
Proceeds from the sales of assets	0	0	225
Grants under the American Recovery and Reinvestment Act of 2009	0	0	923
Cost of removal, net of salvage	(12,064)	(6,036)	(7,553)
Other	(1,224)	(56)	39
Net cash used in investing activities	(695,117)	(397,375)	(254,537)
CASH FLOWS FROM FINANCING ACTIVITIES:
Short-term debt borrowings	388,850	105,000	150,500
Short-term debt repayments	(272,000)	(105,000)	(150,500)
Long-term borrowings, net of discount	348,638	128,358	169,728
Retirement of long-term debt and early tender premium	(131,850)	0	(110,377)
Dividends on common stock	(103,747)	(127,400)	(90,150)
Equity contributions from AES	214,364	106,400	49,091
Dividends on preferred stock	(3,213)	(3,213)	(3,213)
Payments for financed capital expenditures	(13,215)	0	0
Other	(3,819)	(1,920)	(2,004)
Net cash provided by financing activities	424,008	102,225	13,075
Net change in cash and cash equivalents	(1,147)	8,879	78
Cash and cash equivalents at beginning of period	20,999	12,120	12,042
Cash and cash equivalents at end of period	19,852	20,999	12,120
Cash paid during the period for:
Interest (net of amount capitalized)	53,447	54,938	57,175
Income taxes	25,000	0	64,950
Non-cash investing activities:
Accruals for capital expenditures	$ 79,553	$ 37,293	$ 17,957

Consolidated Statements Of Comm

Consolidated Statements Of Common Shareholders' Equity (Deficit) And Noncontrolling Interest - USD ($) $ in Thousands	Total	Paid In Capital [Member]	Accumulated Deficit [Member]	Cumulative Preferred Stock Of Subsidiary [Member]	Indianapolis Power And Light Company [Member]	Indianapolis Power And Light Company [Member]Corporate Stocks - Common [Member]	Indianapolis Power And Light Company [Member]Paid In Capital [Member]	Indianapolis Power And Light Company [Member]Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2012	$ (3,219)	$ 11,811	$ (15,030)	$ 59,784	$ 786,235	$ 324,537	$ 13,536	$ 448,162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income applicable to common stock	60,836		60,836	3,213	93,339
Net income	64,049				96,552			96,552
Preferred stock dividends				(3,213)	(3,213)			(3,213)
Cash dividends declared on common stock					(90,150)			(90,150)
Distributions to AES	(59,500)		(59,500)
Contributions from AES	49,091	49,091			49,091		49,091
Other	566	566			546		546
Ending Balance at Dec. 31, 2013	47,774	61,468	(13,694)	59,784	839,061	324,537	63,173	451,351
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income applicable to common stock	74,755		74,755	3,213	106,315
Net income	77,968				109,528			109,528
Preferred stock dividends				(3,213)	(3,213)			(3,213)
Cash dividends declared on common stock					(127,400)			(127,400)
Distributions to AES	(78,400)		(78,400)
Contributions from AES	106,400	106,400			106,400		106,400
Other	742	742			733		733
Ending Balance at Dec. 31, 2014	151,271	168,610	(17,339)	59,784	925,109	324,537	170,306	430,266
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income applicable to common stock	56,311		56,311	3,213	98,708
Net income	59,524				101,921			101,921
Preferred stock dividends				(3,213)	(3,213)			(3,213)
Cash dividends declared on common stock					(113,747)			(113,747)
Distributions to AES	(69,487)		(69,487)
Issuance of common stock	214,366	214,366
Contributions from AES					214,364		214,364
Other	472	472			470		470
Ending Balance at Dec. 31, 2015	$ 352,933	$ 383,448	$ (30,515)	$ 59,784	$ 1,124,904	$ 324,537	$ 385,140	$ 415,227

Overview and Summary of Signifi

Overview and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Overview and Summary of Significant Accounting Policies	OVERVIEW AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES IPALCO is a holding company incorporated under the laws of the state of Indiana. IPALCO, acquired by AES in March 2001, is owned by AES U.S. Investments ( 88.4% ) and CDPQ ( 11.6% ), IPALCO’s minority interest holder (see Note 6, “ Equity - Equity Transactions ” for details). AES U.S. Investments is owned by AES U.S. Holdings, LLC ( 85% ) and CDPQ ( 15% ). IPALCO owns all of the outstanding common stock of IPL. Substantially all of IPALCO’s business consists of generating, transmitting, distributing and selling of electric energy conducted through its principal subsidiary, IPL. IPL was incorporated under the laws of the state of Indiana in 1926. IPL has approximately 480,000 retail customers in the city of Indianapolis and neighboring cities, towns and communities, and adjacent rural areas all within the state of Indiana, with the most distant point being approximately forty miles from Indianapolis. IPL has an exclusive right to provide electric service to those customers. IPL owns and operates four generating stations all within the state of Indiana. Our largest generating station, Petersburg, is coal-fired. The second largest station, Harding Street, is converting its coal-fired units to natural gas and uses natural gas and fuel oil to power combustion turbines. The third station, Eagle Valley, is coal-fired and we plan to retire its coal-fired units in the second quarter of 2016. The fourth station, Georgetown, is a small peaking station that uses natural gas to power combustion turbines. IPL’s net electric generation capacity for winter is 3,259 MW and net summer capacity is 3,141 MW. IPALCO’s other direct subsidiary is Mid-America. Mid-America is the holding company for IPALCO’s unregulated activities, which have not been material to the financial statements in the periods covered by this report. IPALCO’s regulated business is conducted through IPL. IPALCO has two business segments: utility and nonutility. The utility segment consists of the operations of IPL and everything else is included in the nonutility segment. Principles of Consolidation IPALCO’s consolidated financial statements are prepared in accordance with GAAP and in conjunction with the rules and regulations of the SEC. The consolidated financial statements include the accounts of IPALCO, its regulated utility subsidiary, IPL, and its unregulated subsidiary, Mid-America. All intercompany items have been eliminated in consolidation. Certain costs for shared resources amongst IPL and IPALCO, such as labor and benefits, are allocated to each entity based on allocation methodologies that management believes to be reasonable. We have evaluated subsequent events through the date this report is issued. All income of Mid-America, as well as nonoperating income of IPL, are included below UTILITY OPERATING INCOME in the accompanying Consolidated Statements of Income. Use of Management Estimates The preparation of financial statements in conformity with GAAP requires that management make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. The reported amounts of revenues and expenses during the reporting period may also be affected by the estimates and assumptions management is required to make. Actual results may differ from those estimates. Reclassifications Certain prior period amounts have been reclassified to conform to the current year presentation. Regulatory Accounting The retail utility operations of IPL are subject to the jurisdiction of the IURC. IPL’s wholesale power transactions are subject to the jurisdiction of the FERC. These agencies regulate IPL’s utility business operations, tariffs, accounting, depreciation allowances, services, issuances of securities and the sale and acquisition of utility properties. The financial statements of IPL are based on GAAP, including the provisions of FASB ASC 980 “Regulated Operations,” which gives recognition to the ratemaking and accounting practices of these agencies. See also Note 5, “Regulatory Assets and Liabilities” for a discussion of specific regulatory assets and liabilities. Revenues and Accounts Receivable Revenues related to the sale of energy are generally recognized when service is rendered or energy is delivered to customers. However, the determination of the energy sales to individual customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to certain customers since the date of the last meter reading are estimated and the corresponding unbilled revenue is accrued. In making its estimates of unbilled revenue, IPL uses complex models that consider various factors including daily generation volumes; known amounts of energy usage by nearly all residential, small commercial and industrial customers; estimated line losses; and estimated customer rates based on prior period billings. Given the use of these models, and that customers are billed on a monthly cycle, we believe it is unlikely that materially different results will occur in future periods when revenue is billed. At December 31, 2015 and 2014 , customer accounts receivable include unbilled energy revenues of $42.1 million and $48.4 million , respectively, on a base of annual revenue of $ 1.3 billion in 2015 and 2014 . An allowance for potential credit losses is maintained and amounts are written off when normal collection efforts have been exhausted. Our provision for doubtful accounts included in “Other operating expenses” on the accompanying Consolidated Statements of Income was $4.3 million , $4.9 million and $ 3.8 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. IPL’s basic rates include a provision for fuel costs as established in IPL’s most recent rate proceeding, which last adjusted IPL’s rates in 1996. IPL is permitted to recover actual costs of purchased power and fuel consumed, subject to certain restrictions. This is accomplished through quarterly FAC proceedings, in which IPL estimates the amount of fuel and purchased power costs in future periods. Through these proceedings, IPL is also permitted to recover, in future rates, underestimated fuel and purchased power costs from prior periods, subject to certain restrictions, and therefore the over or underestimated costs are deferred or accrued and amortized into fuel expense in the same period that IPL’s rates are adjusted. See also Note 2, “ Regulatory Matters ,” for a discussion of other costs that IPL is permitted to recover through periodic rate adjustment proceedings and the status of current rate adjustment proceedings. In addition, we are one of many transmission system owner members of MISO, a regional transmission organization which maintains functional control over the combined transmission systems of its members and manages one of the largest energy markets in the U.S. In the MISO market, IPL offers its generation and bids its demand into the market on an hourly basis. MISO settles these hourly offers and bids based on locational marginal prices, which is pricing for energy at a given location based on a market clearing price that takes into account physical limitations, generation, and demand throughout the MISO region. MISO evaluates the market participants’ energy offers and demand bids to economically and reliably dispatch the entire MISO system. IPL accounts for these hourly offers and bids, on a net basis, in UTILITY OPERATING REVENUES when in a net selling position and in UTILITY OPERATING EXPENSES – Power Purchased when in a net purchasing position. Contingencies IPALCO accrues for loss contingencies when the amount of the loss is probable and estimable. IPL is subject to various environmental regulations, and is involved in certain legal proceedings. If IPL’s actual environmental and/or legal obligations are different from our estimates, the recognition of the actual amounts may have a material impact on our results of operations, financial condition and cash flows; although that has not been the case during the periods covered by this report. As of December 31, 2015 and 2014 , total loss contingencies accrued were $5.6 million and $5.2 million , respectively, which were included in “Other Current Liabilities” on the accompanying Consolidated Balance Sheets. Concentrations of Risk Substantially all of IPL’s customers are located within the Indianapolis area. In addition, approximately 65% of IPL’s full-time employees are covered by collective bargaining agreements in two bargaining units: a physical unit and a clerical-technical unit. IPL’s contract with the physical unit expires on December 10, 2018 , and the contract with the clerical-technical unit expires February 20, 2017 . Additionally, IPL has long-term coal contracts with four suppliers, with about 53% of our existing coal under contract for the three-year period ending December 31, 2018 coming from one supplier. Substantially all of the coal is currently mined in the state of Indiana. Allowance For Funds Used During Construction In accordance with the Uniform System of Accounts prescribed by FERC, IPL capitalizes an allowance for the net cost of funds (interest on borrowed funds and a reasonable rate of return on equity funds) used for construction purposes during the period of construction with a corresponding credit to income. IPL capitalized amounts using pretax composite rates of 8.1% , 8.3% and 8.6% during 2015 , 2014 and 2013 , respectively. For the Eagle Valley CCGT, Harding Street refueling projects, and NPDES projects, IPL capitalized amounts using a pretax composite rate of 7.3% and 7.6% during 2015 and 2014, respectively. Utility Plant and Depreciation Utility plant is stated at original cost as defined for regulatory purposes. The cost of additions to utility plant and replacements of retirement units of property are charged to plant accounts. Units of property replaced or abandoned in the ordinary course of business are retired from the plant accounts at cost; such amounts, less salvage, are charged to accumulated depreciation. Depreciation is computed by the straight-line method based on functional rates approved by the IURC and averaged 4.2% , 4.1% , and 4.0% during 2015 , 2014 and 2013 , respectively. Depreciation expense was $198.8 million , $185.9 million , and $180.0 million for the years ended December 31, 2015 , 2014 and 2013 , respectively, which includes depreciation expense that has been deferred as a regulatory asset. Derivatives We have only limited involvement with derivative financial instruments and do not use them for trading purposes. IPALCO accounts for its derivatives in accordance with ASC 815 “Derivatives and Hedging.” In addition, IPL has entered into contracts involving the physical delivery of energy and fuel. Because these contracts qualify for the normal purchases and normal sales scope exception in ASC 815, IPL has elected to account for them as accrual contracts, which are not adjusted for changes in fair value. Fuel, Materials and Supplies We maintain coal, fuel oil, materials and supplies inventories for use in the production of electricity. These inventories are accounted for at the lower of cost or market, using the average cost. Impairment of Long-lived Assets GAAP requires that we measure long-lived assets for impairment when indicators of impairment exist. If an asset is deemed to be impaired, we are required to write down the asset to its fair value with a charge to current earnings. The net book value of our utility plant assets was $3.5 billion and $2.9 billion as of December 31, 2015 and 2014 , respectively. We do not believe any of these assets are currently impaired. In making this assessment, we consider such factors as: the overall condition and generating and distribution capacity of the assets; the expected ability to recover additional expenditures in the assets, such as CCT projects; the anticipated demand and relative pricing of retail electricity in our service territory and wholesale electricity in the region; and the cost of fuel. Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of the existing assets and liabilities, and their respective income tax bases. The Company establishes a valuation allowance when it is more likely than not that all or a portion of a deferred tax asset will not be realized. The Company’s tax positions are evaluated under a more likely than not recognition threshold and measurement analysis before they are recognized for financial statement reporting. Uncertain tax positions have been classified as noncurrent income tax liabilities unless expected to be paid within one year. The Company’s policy for interest and penalties is to recognize interest and penalties as a component of the provision for income taxes in the Consolidated Statements of Operations. Income taxes payable which are includable in allowable costs for ratemaking purposes in future years are recorded as regulatory assets with a corresponding deferred tax liability. Investment tax credits that reduced federal income taxes in the years they arose have been deferred and are being amortized to income over the useful lives of the properties in accordance with regulatory treatment. Cash and Cash Equivalents Cash and cash equivalents are stated at cost, which approximates fair value. All highly liquid short-term investments with original maturities of three months or less are considered cash equivalents. Pension and Postretirement Benefits We recognize in our Consolidated Balance Sheets an asset or liability reflecting the funded status of pension and other postretirement plans with current-year changes in the funded status, that would otherwise be recognized in AOCI, recorded as a regulatory asset as this can be recovered through future rates. All plan assets are recorded at fair value. We follow the measurement date provisions of the accounting guidance, which require a year-end measurement date of plan assets and obligations for all defined benefit plans. We account for and disclose pension and postretirement benefits in accordance with the provisions of GAAP relating to the accounting for pension and other postretirement plans. These GAAP provisions require the use of assumptions, such as the discount rate for liabilities and long-term rate of return on assets, in determining the obligations, annual cost and funding requirements of the plans. Effective January 1, 2016, we will apply a disaggregated discount rate approach for determining service cost and interest cost for our defined benefit pension plans and postretirement plans. This approach is consistent with the requirements of ASC 715 and is considered to be preferential to the aggregated single rate discount approach, which has historically been used in the U.S., because it is more consistent with the philosophy of a full yield curve valuation. The change in discount rate approach did not have an impact on the measurement of the benefit obligations at December 31, 2015, nor will it impact future remeasurements. This change in approach will impact the service cost and interest cost recorded in 2016 and future years. It will also impact the actuarial gains and losses recorded in future years, as well as the amortization thereof. The expected 2016 service costs and interest costs included in Note 9, “ Benefit Plans ” reflect the change in methodology described above. The impact of the change in approach on expected service costs in 2016 is shown below: $ in thousands Expected 2016 Service Cost Expected 2016 Interest Cost Disaggregated rate approach Aggregate rate approach Impact of change Disaggregated rate approach Aggregate rate approach Impact of change Pension $ 7,018 $ 7,382 $ (364 ) $ 25,634 $ 30,916 $ (5,282 ) Repair and Maintenance Costs Repair and maintenance costs are expensed as incurred. Per Share Data IPALCO is owned by AES U.S. Investments and CDPQ, IPALCO’s minority interest holder. IPALCO does not report earnings on a per-share basis. New Accounting Pronouncements ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) In May 2014, the FASB issued ASU No. 2014-09 which clarifies principles for recognizing revenue and will result in a common revenue standard for GAAP and International Financial Reporting Standards. The objective of the new standard is to provide a single and comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. The standard requires an entity to recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14 , Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date, which deferred the effective date of ASU 2014-09 by one year, resulting in the new revenue standard being effective for annual reporting periods beginning after December 15, 2017 and interim periods therein. Early adoption is now permitted only as of the original effective date for public entities (that is, no earlier than 2017 for calendar year-end entities). The standard permits the use of either a full retrospective or modified retrospective approach. The Company has not yet selected a transition method and is currently evaluating the impact of adopting the standard on its consolidated financial statements. ASU No. 2015-02, Consolidation - Amendments to the Consolidation Analysis (Topic 810) In February 2015, the FASB issued ASU 2015-02, which makes targeted amendments to the current consolidation guidance and ends the deferral granted to investment companies from applying the VIE guidance. The standard amends the evaluation of whether (1) fees paid to a decision-maker or service providers represent a variable interest, (2) a limited partnership or similar entity has the characteristics of a VIE and (3) a reporting entity is the primary beneficiary of a VIE. The standard is effective for annual periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The Company does not expect this standard to have an impact on its consolidated financial statements upon adoption. ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30) In April 2015, the FASB issued ASU No. 2015-03, which simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this update. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein, and requires the use of the full retrospective approach. Early adoption is permitted for financial statements that have not been previously issued. As of December 31, 2015, the Company had approximately $20.8 million in deferred financing costs classified in other noncurrent assets that would be reclassified to reduce the related debt liabilities upon adoption of ASU No. 2015-03. ASU No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement In April 2015, the FASB issued ASU No. 2015-05, which clarifies how customers in cloud computing arrangements should determine whether the arrangement includes a software license and eliminates the existing requirement for customers to account for software licenses they acquired by analogizing to the accounting guidance on leases. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The standard permits the use of a prospective or retrospective approach. The Company expects to utilize the prospective approach upon adoption of this standard, which is not expected to have a material impact on its consolidated financial statements. ASU No. 2015-11, Simplifying the Measurement of Inventory (Topic 330) In July 2015, the FASB issued ASU No. 2015-11, which simplifies the subsequent measurement of inventory. It replaces the current lower of cost or market test with a lower of cost or net realizable value test. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. Early adoption is permitted. The new guidance must be applied prospectively. As the Company already uses the net realizable value to make lower of cost or market determinations, there will be no impact on its consolidated financial statements upon adoption of this standard. ASU No. 2015-15, Interest - Imputation of Interest (Subtopic 835-30) : Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements In August 2015, the FASB issued ASU No. 2015-15, which clarifies that the SEC Staff would not object to an entity presenting debt issuance costs related to line-of-credit arrangements as an asset that is subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. This standard should be adopted concurrent with adoption of ASU 2015-03 (which is described above). As of December 31, 2015, the Company had deferred financing costs related to lines of credit of approximately $0.3 million recorded within Deferred Debits that would not be reclassified upon adoption of this standard. ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments In September 2015, the FASB issued ASU 2015-16, which simplifies the measurement-period adjustments in business combinations. It eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. An acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The standard is effective for public entities for annual reporting periods beginning after December 15, 2015, and interim periods therein. Early adoption is permitted for financial statements that have not been issued. The new guidance should be applied prospectively to adjustments to provisional amounts that occur after the effective date of this standard. The Company will adopt this standard on January 1, 2016, which is not expected to have a material impact on the Company's consolidated financial statements. ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes Effective December 31, 2015, the Company prospectively adopted ASU No. 2015-17, which requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. As a result, each jurisdiction will now only have one net noncurrent deferred tax asset or liability. The guidance does not change the existing requirement that only permits offsetting within a jurisdiction; that is, companies will remain prohibited from offsetting deferred tax liabilities from one jurisdiction against deferred tax assets of another jurisdiction. Additionally, the current requirement that deferred tax liabilities and assets of a tax-paying component of an entity be offset and presented as a single amount is not affected by the update. As the Company elected to apply this ASU prospectively, prior periods were not adjusted. ASU No. 2016-01, Financial Instruments - Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, which was designed to improve the recognition and measurement of financial instruments through targeted changes to existing GAAP. The guidance requires equity investments (except those that are accounted for under the equity method of accounting or result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; that entities use the exit price notion when measuring financial instrument fair values; that an entity separate presentation of financial assets and liabilities by measurement category and form of financial asset on the Balance Sheets or Notes to the financial statements; that an entity present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk (or “ own credit ” ) when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. Also, the standard eliminates the requirement for public entities to disclose the methods and significant assumptions used to estimate the fair value required to be disclosed for financial instruments measured at amortized cost on the Balance Sheets. The standard is effective beginning with interim periods starting after December 31, 2017 and cannot be applied early. The Company is currently evaluating the applicability and materiality of the standard, but doesn't anticipate a material impact on the Company's consolidated financial statements.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Overview and Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES IPL was incorporated under the laws of the state of Indiana in 1926. All of the outstanding common stock of IPL is owned by IPALCO. IPALCO, acquired by AES in March 2001, is owned by AES U.S. Investments and CDPQ, IPALCO’s minority interest holder. AES U.S. Investments is owned by AES ( 85% ) and CDPQ ( 15% ). IPL is engaged primarily in generating, transmitting, distributing and selling of electric energy to approximately 480,000 retail customers in the city of Indianapolis and neighboring cities, towns and communities, and adjacent rural areas all within the state of Indiana, with the most distant point being approximately forty miles from Indianapolis. IPL has an exclusive right to provide electric service to those customers. IPL owns and operates four generating stations all within the state of Indiana. Our largest generating station, Petersburg, is coal-fired. The second largest station, Harding Street, is converting its coal-fired units to natural gas and uses natural gas and fuel oil to power combustion turbines. The third station, Eagle Valley, is coal-fired, and IPL plans to retire its coal-fired units in the second quarter of 2016. The fourth station, Georgetown, is a small peaking station that uses natural gas to power combustion turbines. IPL’s net electric generation capacity for winter is 3,259 MW and net summer capacity is 3,141 MW. IPL Funding is a special-purpose entity and a wholly-owned subsidiary of IPL and is included in the audited Consolidated Financial Statements of IPL. IPL formed IPL Funding in 1996 to sell, on a revolving basis, up to $50 million of the retail accounts receivable and related collections of IPL to third-party purchasers in exchange for cash (see Accounts Receivable Securitization in Note 7, “ Debt ”). Principles of Consolidation IPL’s consolidated financial statements are prepared in accordance with GAAP and in conjunction with the rules and regulations of the SEC. The consolidated financial statements include the accounts of IPL and its unregulated subsidiary, IPL Funding. All intercompany items have been eliminated in consolidation. Certain costs for shared resources amongst IPL and IPALCO, such as labor and benefits, are allocated to each entity based on allocation methodologies that management believes to be reasonable. We have evaluated subsequent events through the date this report is issued. Use of Management Estimates The preparation of financial statements in conformity with GAAP requires that management make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. The reported amounts of revenues and expenses during the reporting period may also be affected by the estimates and assumptions management is required to make. Actual results may differ from those estimates. Reclassifications Certain prior period amounts have been reclassified to conform to the current year presentation. Regulatory Accounting The retail utility operations of IPL are subject to the jurisdiction of the IURC. IPL’s wholesale power transactions are subject to the jurisdiction of the FERC. These agencies regulate IPL’s utility business operations, tariffs, accounting, depreciation allowances, services, issuances of securities and the sale and acquisition of utility properties. The financial statements of IPL are based on GAAP, including the provisions of FASB ASC 980 “Regulated Operations,” which gives recognition to the ratemaking and accounting practices of these agencies. See also Note 5, “Regulatory Assets and Liabilities” for a discussion of specific regulatory assets and liabilities. Revenues and Accounts Receivable Revenues related to the sale of energy are generally recognized when service is rendered or energy is delivered to customers. However, the determination of the energy sales to individual customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to certain customers since the date of the last meter reading are estimated and the corresponding unbilled revenue is accrued. In making its estimates of unbilled revenue, IPL uses complex models that consider various factors including daily generation volumes; known amounts of energy usage by nearly all residential, small commercial and industrial customers; estimated line losses; and estimated customer rates based on prior period billings. Given the use of these models, and that customers are billed on a monthly cycle, we believe it is unlikely that materially different results will occur in future periods when revenue is billed. At December 31, 2015 and 2014 , customer accounts receivable include unbilled energy revenues of $42.1 million and $48.4 million , respectively, on a base of annual revenue of $1.3 billion in 2015 and 2014 . An allowance for potential credit losses is maintained and amounts are written off when normal collection efforts have been exhausted. Our provision for doubtful accounts included in “ Other operating expenses” on the accompanying Consolidated Statements of Income was $4.3 million , $4.9 million and $3.8 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. IPL’s basic rates include a provision for fuel costs as established in IPL’s most recent rate proceeding, which last adjusted IPL’s rates in 1996. IPL is permitted to recover actual costs of purchased power and fuel consumed, subject to certain restrictions. This is accomplished through quarterly FAC proceedings, in which IPL estimates the amount of fuel and purchased power costs in future periods. Through these proceedings, IPL is also permitted to recover, in future rates, underestimated fuel and purchased power costs from prior periods, subject to certain restrictions, and therefore the over or underestimated costs are deferred or accrued and amortized into fuel expense in the same period that IPL’s rates are adjusted. See also Note 2, “ Regulatory Matters ,” for a discussion of other costs that IPL is permitted to recover through periodic rate adjustment proceedings and the status of current rate adjustment proceedings. In addition, we are one of many transmission system owner members of MISO, a regional transmission organization which maintains functional control over the combined transmission systems of its members and manages one of the largest energy markets in the U.S. In the MISO market, IPL offers its generation and bids its demand into the market on an hourly basis. MISO settles these hourly offers and bids based on locational marginal prices, which is pricing for energy at a given location based on a market clearing price that takes into account physical limitations, generation, and demand throughout the MISO region. MISO evaluates the market participants’ energy offers and demand bids to economically and reliably dispatch the entire MISO system. IPL accounts for these hourly offers and bids, on a net basis, in OPERATING REVENUES when in a net selling position and in OPERATING EXPENSES – Power Purchased when in a net purchasing position. Contingencies IPL accrues for loss contingencies when the amount of the loss is probable and estimable. IPL is subject to various environmental regulations, and is involved in certain legal proceedings. If IPL’s actual environmental and/or legal obligations are different from our estimates, the recognition of the actual amounts may have a material impact on our results of operations, financial condition and cash flows; although that has not been the case during the periods covered by this report. As of December 31, 2015 and 2014 , total loss contingencies accrued were $5.6 million and $5.2 million , respectively, which were included in “ Other Current Liabilities” on the accompanying Consolidated Balance Sheets. Concentrations of Risk Substantially all of IPL’s customers are located within the Indianapolis area. In addition, approximately 65% of IPL’s full-time employees are covered by collective bargaining agreements in two bargaining units: a physical unit and a clerical-technical unit. IPL’s contract with the physical unit expires on December 10, 2018 , and the contract with the clerical-technical unit expires February 20, 2017 . Additionally, IPL has long-term coal contracts with four suppliers, with about 53% of our existing coal under contract for the three-year period ending December 31, 2018 coming from one supplier. Substantially all of the coal is currently mined in the state of Indiana. Allowance For Funds Used During Construction In accordance with the Uniform System of Accounts prescribed by FERC, IPL capitalizes an allowance for the net cost of funds (interest on borrowed funds and a reasonable rate of return on equity funds) used for construction purposes during the period of construction with a corresponding credit to income. IPL capitalized amounts using pretax composite rates of 8.1% , 8.3% and 8.6% during 2015 , 2014 and 2013 , respectively. For the Eagle Valley CCGT, Harding Street refueling projects, and NPDES projects, IPL capitalized amounts using a pretax composite rate of 7.3% and 7.6% during 2015 and 2014, respectively. Utility Plant and Depreciation Utility plant is stated at original cost as defined for regulatory purposes. The cost of additions to utility plant and replacements of retirement units of property are charged to plant accounts. Units of property replaced or abandoned in the ordinary course of business are retired from the plant accounts at cost; such amounts, less salvage, are charged to accumulated depreciation. Depreciation is computed by the straight-line method based on functional rates approved by the IURC and averaged 4.2% , 4.1% , and 4.0% during 2015 , 2014 and 2013 , respectively. Depreciation expense was $198.8 million , $185.9 million , and $180.0 million for the years ended December 31, 2015 , 2014 and 2013 , respectively, which includes depreciation expense that has been deferred as a regulatory asset. Derivatives We have only limited involvement with derivative financial instruments and do not use them for trading purposes. IPL accounts for its derivatives in accordance with ASC 815 “Derivatives and Hedging.” In addition, IPL has entered into contracts involving the physical delivery of energy and fuel. Because these contracts qualify for the normal purchases and normal sales scope exception in ASC 815, IPL has elected to account for them as accrual contracts, which are not adjusted for changes in fair value. Fuel, Materials and Supplies We maintain coal, fuel oil, materials and supplies inventories for use in the production of electricity. These inventories are accounted for at the lower of cost or market, using the average cost. Impairment of Long-lived Assets GAAP requires that we measure long-lived assets for impairment when indicators of impairment exist. If an asset is deemed to be impaired, we are required to write down the asset to its fair value with a charge to current earnings. The net book value of our utility plant assets was $3.5 billion and $2.9 billion as of December 31, 2015 and 2014 , respectively. We do not believe any of these assets are currently impaired. In making this assessment, we consider such factors as: the overall condition and generating and distribution capacity of the assets; the expected ability to recover additional expenditures in the assets, such as CCT projects; the anticipated demand and relative pricing of retail electricity in our service territory and wholesale electricity in the region; and the cost of fuel. Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of the existing assets and liabilities, and their respective income tax bases. The Company establishes a valuation allowance when it is more likely than not that all or a portion of a deferred tax asset will not be realized. The Company’s tax positions are evaluated under a more likely than not recognition threshold and measurement analysis before they are recognized for financial statement reporting. Uncertain tax positions have been classified as noncurrent income tax liabilities unless expected to be paid within one year. The Company’s policy for interest and penalties is to recognize interest and penalties as a component of the provision for income taxes in the Consolidated Statements of Operations. Income taxes payable which are includable in allowable costs for ratemaking purposes in future years are recorded as regulatory assets with a corresponding deferred tax liability. Investment tax credits that reduced federal income taxes in the years they arose have been deferred and are being amortized to income over the useful lives of the properties in accordance with regulatory treatment. Cash and Cash Equivalents Cash and cash equivalents are stated at cost, which approximates fair value. All highly liquid short-term investments with original maturities of three months or less are considered cash equivalents. Pension and Postretirement Benefits We recognize in our Consolidated Balance Sheets an asset or liability reflecting the funded status of pension and other postretirement plans with current-year changes in the funded status, that would otherwise be recognized in AOCI, recorded as a regulatory asset as this can be recovered through future rates. All plan assets are recorded at fair value. We follow the measurement date provisions of the accounting guidance, which require a year-end measurement date of plan assets and obligations for all defined benefit plans. We account for and disclose pension and postretirement benefits in accordance with the provisions of GAAP relating to the accounting for pension and other postretirerment plans. These GAAP provisions require the use of assumptions, such as the discount rate for liabilities and long-term rate of return on assets, in determining the obligations, annual cost and funding requirements of the plans. Effective January 1, 2016, we will apply a disaggregated discount rate approach for determining service cost and interest cost for our defined benefit pension plans and postretirement plans. This approach is consistent with the requirements of ASC 715 and is considered to be preferential to the aggregated single rate discount approach, which has historically been used in the U.S., because it is more consistent with the philosophy of a full yield curve valuation. The change in discount rate approach did not have an impact on the measurement of the benefit obligations at December 31, 2015, nor will it impact future remeasurements. This change in approach will impact the service cost and interest cost recorded in 2016 and future years. It will also impact the actuarial gains and losses recorded in future years, as well as the amortization thereof. The expected 2016 service costs and interest costs included in Note 9, “ Benefit Plans ” reflect the change in methodology described above. The impact of the change in approach on expected service costs in 2016 is shown below: $ in thousands Expected 2016 Service Cost Expected 2016 Interest Cost Disaggregated rate approach Aggregate rate approach Impact of change Disaggregated rate approach Aggregate rate approach Impact of change Pension $ 7,018 $ 7,382 $ (364 ) $ 25,634 $ 30,916 $ (5,282 ) Repair and Maintenance Costs Repair and maintenance costs are expensed as incurred. Per Share Data IPALCO owns all of the outstanding common stock of IPL. IPL does not report earnings on a per-share basis. New Accounting Pronouncements ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) In May 2014, the FASB issued ASU No. 2014-09 which clarifies principles for recognizing revenue and will result in a common revenue standard for GAAP and International Financial Reporting Standards. The objective of the new standard is to provide a single and comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. The standard requires an entity to recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14 , Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date, which deferred the effective date of ASU 2014-09 by one year, resulting in the new revenue standard being effective for annual reporting periods beginning after December 15, 2017 and interim periods therein. Early adoption is now permitted only as of the original effective date for public entities (that is, no earlier than 2017 for calendar year-end entities). The standard permits the use of either a full retrospective or modified retrospective approach. The Company has not yet selected a transition method and is currently evaluating the impact of adopting the standard on its consolidated financial statements. ASU No. 2015-02, Consolidation - Amendments to the Consolidation Analysis (Topic 810) In February 2015, the FASB issued ASU 2015-02, which makes targeted amendments to the current consolidation guidance and ends the deferral granted to investment companies from applying the VIE guidance. The standard amends the evaluation of whether (1) fees paid to a decision-maker or service providers represent a variable interest, (2) a limited partnership or similar entity has the characteristics of a VIE and (3) a reporting entity is the primary beneficiary of a VIE. The standard is effective for annual periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The Company does not expect this standard to have an impact on its consolidated financial statements upon adoption. ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30) In April 2015, the FASB issued ASU No. 2015-03, which simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this update. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein, and requires the use of the full retrospective approach. Early adoption is permitted for financial statements that have not been previously issued. As of December 31, 2015, the Company had approximately $13.9 million in deferred financing costs classified in other noncurrent assets that would be reclassified to reduce the related debt liabilities upon adoption of ASU No. 2015-03. ASU No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement In April 2015, the FASB issued ASU No. 2015-05, which clarifies how customers in cloud computing arrangements should determine whether the arrangement includes a software license and eliminates the existing requirement for customers to account for software licenses they acquired by analogizing to the accounting guidance on leases. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The standard permits the use of a prospective or retrospective approach. The Company expects to utilize the prospective approach upon adoption of this standard, which is not expected to have a material impact on its consolidated financial statements. ASU No. 2015-11, Simplifying the Measurement of Inventory (Topic 330) In July 2015, the FASB issued ASU No. 2015-11, which simplifies the subsequent measurement of inventory. It replaces the current lower of cost or market test with a lower of cost or net realizable value test. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. Early adoption is permitted. The new guidance must be applied prospectively. As the Company already uses the net realizable value to make lower of cost or market determinations, there will be no impact on its consolidated financial statements upon adoption of this standard. ASU No. 2015-15, Interest - Imputation of Interest (Subtopic 835-30) : Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements In August 2015, the FASB issued ASU No. 2015-15, which clarifies that the SEC Staff would not object to an entity presenting debt issuance costs related to line-of-credit arrangements as an asset that is subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. This standard should be adopted concurrent with adoption of ASU 2015-03 (which is described above). As of December 31, 2015, the Company had deferred financing costs related to lines of credit of approximately $0.3 million recorded within Deferred Debits that would not be reclassified upon adoption of this standard. ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments In September 2015, the FASB issued ASU 2015-16, which simplifies the measurement-period adjustments in business combinations. It eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. An acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The standard is effective for public entities for annual reporting periods beginning after December 15, 2015, and interim periods therein. Early adoption is permitted for financial statements that have not been issued. The new guidance should be applied prospectively to adjustments to provisional amounts that occur after the effective date of this standard. The Company will adopt this standard on January 1, 2016, which is not expected to have a material impact on the Company's consolidated financial statements. ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes Effective December 31, 2015, the Company prospectively adopted ASU No. 2015-17, which requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. As a result, each jurisdiction will now only have one net noncurrent deferred tax asset or liability. The guidance does not change the existing requirement that only permits offsetting within a jurisdiction; that is, companies will remain prohibited from offsetting deferred tax liabilities from one jurisdiction against deferred tax assets of another jurisdiction. Additionally, the current requirement that deferred tax liabilities and assets of a tax-paying component of an entity be offset and presented as a single amount is not affected by the update. As the Company elected to apply this ASU prospectively, prior periods were not adjusted. ASU No. 2016-01, Financial Instruments - Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, which was designed to improve the recognition and measurement of financial instruments through targeted changes to existing GAAP. The guidance requires equity investments (except those that are accounted for under the equity method of accounting or result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; that entities use the exit price notion when measuring financial instrument fair values; that an entity separate presentation of financial assets and liabilities by measurement category and form of financial asset on the Balance Sheets or Notes to the financial statements; that an entity present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk (or “own credit ” ) when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. Also, the standard eliminates the requirement for public entities to disclose the methods and significant assumptions used to estimate the fair value required to be disclosed for financial instruments measured at amortized cost on the Balance Sheets. The standard is effective beginning with interim periods starting after December 31, 2017 and cannot be applied early. The Company is currently evaluating the applicability and materiality of the standard, but doesn't anticipate a material impact on the Company's consolidated financial statements.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Regulatory Matters	REGULATORY MATTERS General IPL is subject to regulation by the IURC as to its services and facilities, the valuation of property, the construction, purchase, or lease of electric generating facilities, the classification of accounts, rates of depreciation, retail rates and charges, the issuance of securities (other than evidences of indebtedness payable less than twelve months after the date of issue), the acquisition and sale of some public utility properties or securities and certain other matters. In addition, IPL is subject to the jurisdiction of the FERC with respect to short-term borrowing not regulated by the IURC, the sale of electricity at wholesale and the transmission of electric energy in interstate commerce, the classification of accounts, reliability standards, and the acquisition and sale of utility property in certain circumstances as provided by the Federal Power Act. As a regulated entity, IPL is required to use certain accounting methods prescribed by regulatory bodies which may differ from those accounting methods required to be used by unregulated entities. IPL is also affected by the regulatory jurisdiction of the EPA at the federal level, and the IDEM at the state level. Other significant regulatory agencies affecting IPL include, but are not limited to, the NERC, the U.S. Department of Labor and the IOSHA. Basic Rates and Charges Our basic rates and charges represent the largest component of our annual revenues. Our basic rates and charges are determined after giving consideration, on a pro-forma basis, to all allowable costs for ratemaking purposes including a fair return on the fair value of the utility property used and useful in providing service to customers. These basic rates and charges are set and approved by the IURC after public hearings. Such proceedings, which have occurred at irregular intervals, involve IPL, the IURC, the Indiana Office of Utility Consumer Counselor, and other interested stakeholders. Pursuant to statute, the IURC is to conduct a periodic review of the basic rates and charges of all Indiana utilities at least once every four years, but the IURC has the authority to review the rates of any Indiana utility at any time. Once set, the basic rates and charges authorized do not assure the realization of a fair return on the fair value of property. Our basic rates and charges were last adjusted in 1996; however, IPL filed a petition with the IURC on December 29, 2014, for authority to increase its basic rates and charges. IPL's proposed increase, filed as part of IPL's rebuttal testimony in this proceeding, is $63.3 million annually, or 5.3% . An order on this proceeding will likely be issued by the IURC early in 2016. The petition also includes requests to implement rate adjustment mechanisms for short-term recovery of fluctuations in the following costs: (1) capacity purchase costs; (2) off-systems sales margins; and (3) MISO non-fuel charges (MISO fuel charges are already included in the FAC rate mechanism as described below). No assurances can be given as to the timing or outcome of this proceeding. See “ Rate Case and Downtown Underground Network Investigation ” below for further details. Our declining block rate structure generally provides for residential and commercial customers to be charged a lower per kWh rate at higher consumption levels. Therefore, as volumes increase, the weighted average price per kWh decreases. Numerous factors including, but not limited to, weather, inflation, customer growth and usage, the level of actual operating and maintenance expenditures, capital expenditures including those required by environmental regulations, fuel costs, generating unit availability and purchased power costs, can affect the return realized. Rate Case and Downtown Underground Network Investigation As discussed above, IPL filed a petition with the IURC on December 29, 2014, for authority to increase its basic rates and charges. In response to underground network incidents that occurred in the downtown Indianapolis area, the IURC issued an order on March 20, 2015 opening an investigation of our ongoing investment in, and operation and maintenance of, our network facilities. In 2015, the IURC combined this pending investigation with our petition filed in 2014 proposing to increase our basic rates and charges. The outcome of the rate case and/or downtown underground network investigation cannot be predicted. FAC and Authorized Annual Jurisdictional Net Operating Income IPL may apply to the IURC for a change in IPL’s fuel charge every three months to recover IPL’s estimated fuel costs, including the energy portion of purchased power costs, which may be above or below the levels included in IPL’s basic rates and charges. IPL must present evidence in each FAC proceeding that it has made every reasonable effort to acquire fuel and generate or purchase power or both so as to provide electricity to its retail customers at the lowest fuel cost reasonably possible. Independent of the IURC’s ability to review basic rates and charges, Indiana law requires electric utilities under the jurisdiction of the IURC to meet operating expense and income test requirements as a condition for approval of requested changes in the FAC. Additionally, customer refunds may result if a utility’s rolling twelve-month operating income, determined at quarterly measurement dates, exceeds a utility’s authorized annual jurisdictional net operating income and there are not sufficient applicable cumulative net operating income deficiencies against which the excess rolling twelve-month jurisdictional net operating income can be offset. ECCRA IPL may apply to the IURC for approval of a rate adjustment known as the ECCRA every six months to recover costs to comply with certain environmental regulations applicable to IPL's generating stations. The total amount of IPL’s equipment approved for ECCRA recovery as of December 31, 2015 was $978 million . The jurisdictional revenue requirement that was approved by the IURC to be included in IPL’s rates for the six-month period from September 2015 through February 2016 was $82.0 million . During the years ended December 31, 2015 , 2014 and 2013 , we made environmental compliance expenditures of $252.2 million , $176.3 million , and $126.6 million , respectively. The vast majority of such costs are recoverable through our ECCRA filings. DSM In March 2014, legislation, referred to as the SEA 340, was approved that effectively ended the IURC’s energy efficiency targets established in a 2009 statewide Generic DSM Order. Although SEA 340 puts an end to established efficiency targets, IPL will continue to offer cost-effective energy efficiency and demand response programs as one of many resources to meet future demand for electricity. In December 2014, we received approval from the IURC of our 2015-2016 DSM plan. The approval includes cost recovery on a set of DSM programs to be offered in 2015-2016 that is similar to the 2014 set of programs. Similar to the current DSM framework, we are eligible to receive performance incentives dependent upon the level of success of the programs. Additionally, we were granted authority to record a regulatory asset for recovery in a future base rate case proceeding for lost margins which result from decreased kWh related to implementation of these DSM programs. In May 2015, SEA 412 became law in Indiana. Among other things, SEA 412 requires the IURC to adopt rules regarding the submission of an integrated resource plan. The IURC rulemaking required by SEA 412 is currently in progress. SEA 412 also requires certain electricity suppliers to submit energy efficiency plans to the IURC at least once every three years. Wind and Solar Power Purchase Agreements We are committed under a power purchase agreement to purchase all wind-generated electricity through 2029 from a wind project in Indiana. We are also committed under another agreement to purchase all wind-generated electricity for 20 years from a project in Minnesota. The Indiana project has a maximum output capacity of approximately 100 MW. The Minnesota project, which began commercial operation in October 2011, has a maximum output capacity of approximately 200 MW. In addition, we have 97 MW of solar-generated electricity in our service territory under long-term contracts in 2016, of which 95 MW was in operation as of December 31, 2015 . We have authority from the IURC to recover the costs for all of these agreements through an adjustment mechanism administered within the FAC. MISO Transmission Expansion Cost Sharing MISO transmission system owner members including IPL share the costs of transmission expansion projects with other MISO transmission system owner members after such projects are approved by the MISO board of directors. As required by FERC, IPL participates in a regional transmission planning process with MISO and other MISO transmission providers to produce a regional transmission plan. Upon approval by the MISO board of directors the transmission system owner members must make a good faith effort to build and/or pay for the approved projects they submitted. Costs allocated to IPL for the projects of other transmission system owner members are collected by MISO per their tariff. These charges are difficult to estimate and amounted to $12.1 million in 2015. It is probable, but not certain, that these costs will be recovered through IPL's tariff, subject to IURC approval. Through December 31, 2015 , we have deferred as a long-term regulatory asset $ 19.7 million of MISO transmission expansion costs.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Regulatory Matters	. REGULATORY MATTERS General IPL is subject to regulation by the IURC as to its services and facilities, the valuation of property, the construction, purchase, or lease of electric generating facilities, the classification of accounts, rates of depreciation, retail rates and charges, the issuance of securities (other than evidences of indebtedness payable less than twelve months after the date of issue), the acquisition and sale of some public utility properties or securities and certain other matters. In addition, IPL is subject to the jurisdiction of the FERC with respect to short-term borrowing not regulated by the IURC, the sale of electricity at wholesale and the transmission of electric energy in interstate commerce, the classification of accounts, reliability standards, and the acquisition and sale of utility property in certain circumstances as provided by the Federal Power Act. As a regulated entity, IPL is required to use certain accounting methods prescribed by regulatory bodies which may differ from those accounting methods required to be used by unregulated entities. IPL is also affected by the regulatory jurisdiction of the EPA at the federal level, and the IDEM at the state level. Other significant regulatory agencies affecting IPL include, but are not limited to, the NERC, the U.S. Department of Labor and the IOSHA. Basic Rates and Charges Our basic rates and charges represent the largest component of our annual revenues. Our basic rates and charges are determined after giving consideration, on a pro-forma basis, to all allowable costs for ratemaking purposes including a fair return on the fair value of the utility property used and useful in providing service to customers. These basic rates and charges are set and approved by the IURC after public hearings. Such proceedings, which have occurred at irregular intervals, involve IPL, the IURC, the Indiana Office of Utility Consumer Counselor, and other interested stakeholders. Pursuant to statute, the IURC is to conduct a periodic review of the basic rates and charges of all Indiana utilities at least once every four years, but the IURC has the authority to review the rates of any Indiana utility at any time. Once set, the basic rates and charges authorized do not assure the realization of a fair return on the fair value of property. Our basic rates and charges were last adjusted in 1996; however, IPL filed a petition with the IURC on December 29, 2014, for authority to increase its basic rates and charges. IPL's proposed increase, filed as part of IPL's rebuttal testimony in this proceeding, is $63.3 million annually, or 5.3% . An order on this proceeding will likely be issued by the IURC early in 2016. . The petition also includes requests to implement rate adjustment mechanisms for short-term recovery of fluctuations in the following costs: (1) capacity purchase costs; (2) off-systems sales margins; and (3) MISO non-fuel charges (MISO fuel charges are already included in the FAC rate mechanism as described below). No assurances can be given as to the timing or outcome of this proceeding. See “ Rate Case and Downtown Underground Network Investigation ” below for further details. Our declining block rate structure generally provides for residential and commercial customers to be charged a lower per kWh rate at higher consumption levels. Therefore, as volumes increase, the weighted average price per kWh decreases. Numerous factors including, but not limited to, weather, inflation, customer growth and usage, the level of actual operating and maintenance expenditures, capital expenditures including those required by environmental regulations, fuel costs, generating unit availability and purchased power costs, can affect the return realized. Rate Case and Downtown Underground Network Investigation As discussed above, IPL filed a petition with the IURC on December 29, 2014, for authority to increase its basic rates and charges. In response to underground network incidents that occurred in the downtown Indianapolis area, the IURC issued an order on March 20, 2015 opening an investigation of our ongoing investment in, and operation and maintenance of, our network facilities. In 2015, the IURC combined this pending investigation with our petition filed in 2014 proposing to increase our basic rates and charges. The outcome of the rate case and/or downtown underground network investigation cannot be predicted. FAC and Authorized Annual Jurisdictional Net Operating Income IPL may apply to the IURC for a change in IPL’s fuel charge every three months to recover IPL’s estimated fuel costs, including the energy portion of purchased power costs, which may be above or below the levels included in IPL’s basic rates and charges. IPL must present evidence in each FAC proceeding that it has made every reasonable effort to acquire fuel and generate or purchase power or both so as to provide electricity to its retail customers at the lowest fuel cost reasonably possible. Independent of the IURC’s ability to review basic rates and charges, Indiana law requires electric utilities under the jurisdiction of the IURC to meet operating expense and income test requirements as a condition for approval of requested changes in the FAC. Additionally, customer refunds may result if a utility’s rolling twelve-month operating income, determined at quarterly measurement dates, exceeds a utility’s authorized annual jurisdictional net operating income and there are not sufficient applicable cumulative net operating income deficiencies against which the excess rolling twelve-month jurisdictional net operating income can be offset. ECCRA IPL may apply to the IURC for approval of a rate adjustment known as the ECCRA every six months to recover costs to comply with certain environmental regulations applicable to IPL's generating stations. The total amount of IPL’s equipment approved for ECCRA recovery as of December 31, 2015 was $978 million . The jurisdictional revenue requirement that was approved by the IURC to be included in IPL’s rates for the six-month period from September 2015 through February 2016 was $82.0 million . During the years ended December 31, 2015 , 2014 and 2013 , we made environmental compliance expenditures of $252.2 million , $176.3 million , and $126.6 million , respectively. The vast majority of such costs are recoverable through our ECCRA filings. DSM In March 2014, legislation, referred to as the SEA 340, was approved that effectively ended the IURC’s energy efficiency targets established in a 2009 statewide Generic DSM Order. Although SEA 340 puts an end to established efficiency targets, IPL will continue to offer cost-effective energy efficiency and demand response programs as one of many resources to meet future demand for electricity. In December 2014, we received approval from the IURC of our 2015-2016 DSM plan. The approval includes cost recovery on a set of DSM programs to be offered in 2015-2016 that is similar to the 2014 set of programs. Similar to the current DSM framework, we are eligible to receive performance incentives dependent upon the level of success of the programs. Additionally, we were granted authority to record a regulatory asset for recovery in a future base rate case proceeding for lost margins which result from decreased kWh related to implementation of these DSM programs. In May 2015, SEA 412 became law in Indiana. Among other things, SEA 412 requires the IURC to adopt rules regarding the submission of an integrated resource plan. The IURC rulemaking required by SEA 412 is currently in progress. SEA 412 also requires certain electricity suppliers to submit energy efficiency plans to the IURC at least once every three years. Wind and Solar Power Purchase Agreements We are committed under a power purchase agreement to purchase all wind-generated electricity through 2029 from a wind project in Indiana. We are also committed under another agreement to purchase all wind-generated electricity for 20 years from a project in Minnesota. The Indiana project has a maximum output capacity of approximately 100 MW. The Minnesota project, which began commercial operation in October 2011, has a maximum output capacity of approximately 200 MW. In addition, we have 97 MW of solar-generated electricity in our service territory under long-term contracts in 2016, of which 95 MW was in operation as of December 31, 2015 . We have authority from the IURC to recover the costs for all of these agreements through an adjustment mechanism administered within the FAC. MISO Transmission Expansion Cost Sharing MISO transmission system owner members including IPL share the costs of transmission expansion projects with other MISO transmission system owner members after such projects are approved by the MISO board of directors. As required by FERC, IPL participates in a regional transmission planning process with MISO and other MISO transmission providers to produce a regional transmission plan. Upon approval by the MISO board of directors the transmission system owner members must make a good faith effort to build and/or pay for the approved projects they submitted. Costs allocated to IPL for the projects of other transmission system owner members are collected by MISO per their tariff. These charges are difficult to estimate and amounted to $12.1 million in 2015. It is probable, but not certain, that these costs will be recovered through IPL's tariff, subject to IURC approval. Through December 31, 2015 , we have deferred as a long-term regulatory asset $19.7 million of MISO transmission expansion costs.

Utility Plant In Service

Utility Plant In Service	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Utility Plant In Service	UTILITY PLANT IN SERVICE The original cost of utility plant in service segregated by functional classifications follows: As of December 31, 2015 2014 (In Thousands) Production $ 3,111,674 $ 2,862,579 Transmission 293,767 268,594 Distribution 1,371,029 1,323,190 General plant 216,124 203,660 Total utility plant in service $ 4,992,594 $ 4,658,023 Substantially all of IPL’s property is subject to a $1,283.5 million direct first mortgage lien, as of December 31, 2015 , securing IPL’s first mortgage bonds. Property under capital leases as of December 31, 2015 and 2014 was insignificant. Total non-contractually or legally required removal costs of utility plant in service at December 31, 2015 and 2014 were $673.8 million and $636.8 million , respectively; and total contractually or legally required removal costs of utility plant in service at December 31, 2015 and 2014 were $59.0 million and $59.1 million , respectively. Please see “ – ARO” below for further information. IPL anticipates material additional costs to comply with various pending and final federal legislation and regulations and it is IPL’s intent to seek recovery of any additional costs. The majority of the expenditures for construction projects designed to reduce SO 2 and mercury emissions are recoverable from jurisdictional retail customers as part of IPL’s CCT projects; however, since jurisdictional retail rates are subject to regulatory approval, there can be no assurance that all costs will be recovered in rates. ARO ASC 410 “Asset Retirement and Environmental Obligations” addresses financial accounting and reporting for legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal operation. A legal obligation for purposes of ASC 410 is an obligation that a party is required to settle as a result of an existing law, statute, ordinance, written or oral contract or the doctrine of promissory estoppel. IPL’s ARO relates primarily to environmental issues involving asbestos, ash ponds, landfills and miscellaneous contaminants associated with its generating plants, transmission system and distribution system. The following is a reconciliation of the ARO legal liability year end balances: 2015 2014 (In Millions) Balance as of January 1 $ 59.1 $ 41.4 Liabilities incurred 0.6 — Liabilities settled (2.5 ) — Revisions in estimated cash flows (1.3 ) 15.4 Accretion expense 3.1 2.3 Balance as of December 31 $ 59.0 $ 59.1 As of December 31, 2015 and 2014 , IPL did not have any assets that are legally restricted for settling its ARO liability.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Utility Plant In Service	. UTILITY PLANT IN SERVICE The original cost of utility plant in service segregated by functional classifications follows: As of December 31, 2015 2014 (In Thousands) Production $ 3,111,674 $ 2,862,579 Transmission 293,767 268,594 Distribution 1,371,029 1,323,190 General plant 216,124 203,660 Total utility plant in service $ 4,992,594 $ 4,658,023 Substantially all of IPL’s property is subject to a $1,283.5 million direct first mortgage lien, as of December 31, 2015 , securing IPL’s first mortgage bonds. Property under capital leases as of December 31, 2015 and 2014 was insignificant. Total non-contractually or legally required removal costs of utility plant in service at December 31, 2015 and 2014 were $673.8 million and $636.8 million , respectively; and total contractually or legally required removal costs of utility plant in service at December 31, 2015 and 2014 were $59.0 million and $59.1 million , respectively. Please see “ – ARO” below for further information. IPL anticipates material additional costs to comply with various pending and final federal legislation and regulations and it is IPL’s intent to seek recovery of any additional costs. The majority of the expenditures for construction projects designed to reduce SO 2 and mercury emissions are recoverable from jurisdictional retail customers as part of IPL’s CCT projects; however, since jurisdictional retail rates are subject to regulatory approval, there can be no assurance that all costs will be recovered in rates. ARO ASC 410 “Asset Retirement and Environmental Obligations” addresses financial accounting and reporting for legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal operation. A legal obligation for purposes of ASC 410 is an obligation that a party is required to settle as a result of an existing law, statute, ordinance, written or oral contract or the doctrine of promissory estoppel. IPL’s ARO relates primarily to environmental issues involving asbestos, ash ponds, landfills and miscellaneous contaminants associated with its generating plants, transmission system and distribution system. The following is a reconciliation of the ARO legal liability year end balances: 2015 2014 (In Millions) Balance as of January 1 $ 59.1 $ 41.4 Liabilities incurred 0.6 — Liabilities settled (2.5 ) — Revisions in estimated cash flows (1.3 ) 15.4 Accretion expense 3.1 2.3 Balance as of December 31 $ 59.0 $ 59.1 As of December 31, 2015 and 2014 , IPL did not have any assets that are legally restricted for settling its ARO liability.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Fair Value	FAIR VALUE The fair value of financial assets and liabilities approximate their reported carrying amounts. The estimated fair values of the Company's assets and liabilities have been determined using available market information. As these amounts are estimates and based on hypothetical transactions to sell assets or transfer liabilities, the use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. Fair Value Hierarchy and Valuation Techniques ASC 820 defined and established a framework for measuring fair value and expands disclosures about fair value measurements for financial assets and liabilities that are adjusted to fair value on a recurring basis and/or financial assets and liabilities that are measured at fair value on a nonrecurring basis, which have been adjusted to fair value during the period. In accordance with ASC 820, we have categorized our financial assets and liabilities that are adjusted to fair value, based on the priority of the inputs to the valuation technique, following the three-level fair value hierarchy prescribed by ASC 820 as follows: Level 1 - unadjusted quoted prices for identical assets or liabilities in an active market; Level 2 - inputs from quoted prices in markets where trading occurs infrequently or quoted prices of instruments with similar attributes in active markets; and Level 3 - unobservable inputs reflecting management’s own assumptions about the inputs used in pricing the asset or liability. Whenever possible, quoted prices in active markets are used to determine the fair value of our financial instruments. Our financial instruments are not held for trading or other speculative purposes. The estimated fair value of financial instruments has been determined by using available market information and appropriate valuation methodologies. However, considerable judgment is required in interpreting market data to develop the estimates of fair value. Accordingly, the estimates presented herein are not necessarily indicative of the amounts that we could realize in a current market exchange. The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. FTRs In connection with IPL’s participation in MISO, in the second quarter of each year IPL is granted financial instruments that can be converted into cash or FTRs based on IPL’s forecasted peak load for the period. FTRs are used in the MISO market to hedge IPL’s exposure to congestion charges, which result from constraints on the transmission system. IPL converts all of these financial instruments into FTRs. IPL’s FTRs are valued at the cleared auction prices for FTRs in MISO’s annual auction. Because of the infrequent nature of this valuation, the fair value assigned to the FTRs is considered a Level 3 input under the fair value hierarchy required by ASC 820. An offsetting regulatory liability has been recorded as these revenues or costs will be flowed through to customers through the FAC. As such, there is no impact on our Consolidated Statements of Income. Other Financial Liabilities As of December 31, 2015 and 2014 , all of IPALCO's financial assets or liabilities measured at fair value on a recurring basis were considered Level 3, based on the fair value hierarchy. Summary The fair value of assets and liabilities at December 31, 2015 measured on a recurring basis and the respective category within the fair value hierarchy for IPALCO was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2015 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 4,150 $ — $ — $ 4,150 Total financial assets measured at fair value $ 4,150 $ — $ — $ 4,150 Financial liabilities: Other derivative liabilities $ 121 $ — $ — $ 121 Total financial liabilities measured at fair value $ 121 $ — $ — $ 121 The fair value of assets and liabilities at December 31, 2014 measured on a recurring basis and the respective category within the fair value hierarchy for IPALCO was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2014 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 6,235 $ — $ — $ 6,235 Total financial assets measured at fair value $ 6,235 $ — $ — $ 6,235 Financial liabilities: Other derivative liabilities $ 140 $ — $ — $ 140 Total financial liabilities measured at fair value $ 140 $ — $ — $ 140 The following table sets forth a reconciliation of financial instruments, measured at fair value on a recurring basis, classified as Level 3 in the fair value hierarchy (note, amounts in this table indicate carrying values, which approximate fair values): Derivative Financial (In Thousands) Balance at January 1, 2014 $ 4,133 Unrealized gain recognized in earnings 16 Issuances 15,710 Settlements (13,764 ) Balance at December 31, 2014 $ 6,095 Unrealized gain recognized in earnings 47 Issuances 13,281 Settlements (15,394 ) Balance at December 31, 2015 $ 4,029 Non-Recurring Fair Value Measurements ASC 410 “Asset Retirement and Environmental Obligations” addresses financial accounting and reporting for legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal operation. A legal obligation for purposes of ASC 410 is an obligation that a party is required to settle as a result of an existing law, statute, ordinance, written or oral contract or the doctrine of promissory estoppel. IPL’s ARO liabilities relate primarily to environmental issues involving asbestos-containing materials, ash ponds, landfills and miscellaneous contaminants associated with its generating plants, transmission system and distribution system. We use the cost approach to determine the fair value of IPL’s ARO liabilities, which is estimated by discounting expected cash outflows to their present value at the initial recording of the liabilities. Cash outflows are based on the approximate future disposal costs as determined by market information, historical information or other management estimates. These inputs to the fair value of the ARO liabilities would be considered Level 3 inputs under the fair value hierarchy. As of December 31, 2015 and 2014, ARO liabilities were $59.0 million and $59.1 million , respectively. See Note 3, “Utility Plant in Service, ” for a rollforward of the ARO liability. Financial Instruments not Measured at Fair Value in the Consolidated Balance Sheets Debt The fair value of our outstanding fixed-rate debt has been determined on the basis of the quoted market prices of the specific securities issued and outstanding. In certain circumstances, the market for such securities was inactive and therefore the valuation was adjusted to consider changes in market spreads for similar securities. Accordingly, the purpose of this disclosure is not to approximate the value on the basis of how the debt might be refinanced. The following table shows the face value and the fair value of fixed-rate and variable-rate indebtedness (Level 2) for the periods ending: December 31, 2015 December 31, 2014 Face Value Fair Value Face Value Fair Value (In Millions) Fixed-rate $ 2,088.4 $ 2,225.3 $ 1,955.3 $ 2,231.2 Variable-rate 256.9 256.9 50.0 50.0 Total indebtedness $ 2,345.3 $ 2,482.2 $ 2,005.3 $ 2,281.2 The difference between the face value and the carrying value of this indebtedness represents unamortized discounts of $4.6 million and $4.3 million at December 31, 2015 and 2014, respectively.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Fair Value	FAIR VALUE The fair value of financial assets and liabilities approximate their reported carrying amounts. The estimated fair values of the Company's assets and liabilities have been determined using available market information. As these amounts are estimates and based on hypothetical transactions to sell assets or transfer liabilities, the use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. Fair Value Hierarchy and Valuation Techniques ASC 820 defined and established a framework for measuring fair value and expands disclosures about fair value measurements for financial assets and liabilities that are adjusted to fair value on a recurring basis and/or financial assets and liabilities that are measured at fair value on a nonrecurring basis, which have been adjusted to fair value during the period. In accordance with ASC 820, we have categorized our financial assets and liabilities that are adjusted to fair value, based on the priority of the inputs to the valuation technique, following the three-level fair value hierarchy prescribed by ASC 820 as follows: Level 1 - unadjusted quoted prices for identical assets or liabilities in an active market; Level 2 - inputs from quoted prices in markets where trading occurs infrequently or quoted prices of instruments with similar attributes in active markets; and Level 3 - unobservable inputs reflecting management’s own assumptions about the inputs used in pricing the asset or liability. Whenever possible, quoted prices in active markets are used to determine the fair value of our financial instruments. Our financial instruments are not held for trading or other speculative purposes. The estimated fair value of financial instruments has been determined by using available market information and appropriate valuation methodologies. However, considerable judgment is required in interpreting market data to develop the estimates of fair value. Accordingly, the estimates presented herein are not necessarily indicative of the amounts that we could realize in a current market exchange. The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. FTRs In connection with IPL’s participation in MISO, in the second quarter of each year IPL is granted financial instruments that can be converted into cash or FTRs based on IPL’s forecasted peak load for the period. FTRs are used in the MISO market to hedge IPL’s exposure to congestion charges, which result from constraints on the transmission system. IPL converts all of these financial instruments into FTRs. IPL’s FTRs are valued at the cleared auction prices for FTRs in MISO’s annual auction. Because of the infrequent nature of this valuation, the fair value assigned to the FTRs is considered a Level 3 input under the fair value hierarchy required by ASC 820. An offsetting regulatory liability has been recorded as these revenues or costs will be flowed through to customers through the FAC. As such, there is no impact on our Consolidated Statements of Income. Other Financial Liabilities IPL did not have any financial assets or liabilities measured at fair value on a nonrecurring basis, which have been adjusted to fair value during the periods covered by this report. As of December 31, 2015 and 2014 , all of IPL’s financial assets or liabilities measured at fair value on a recurring basis were considered Level 3, based on the fair value hierarchy. Summary The fair value of assets and liabilities at December 31, 2015 measured on a recurring basis and the respective category within the fair value hierarchy for IPL was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2015 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 4,150 $ — $ — $ 4,150 Total financial assets measured at fair value $ 4,150 $ — $ — $ 4,150 Financial liabilities: Other derivative liabilities $ 121 $ — $ — $ 121 Total financial liabilities measured at fair value $ 121 $ — $ — $ 121 The fair value of assets and liabilities at December 31, 2014 measured on a recurring basis and the respective category within the fair value hierarchy for IPL was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2014 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 6,235 $ — $ — $ 6,235 Total financial assets measured at fair value $ 6,235 $ — $ — $ 6,235 Financial liabilities: Other derivative liabilities $ 140 $ — $ — $ 140 Total financial liabilities measured at fair value $ 140 $ — $ — $ 140 The following table sets forth a reconciliation of financial instruments, measured at fair value on a recurring basis, classified as Level 3 in the fair value hierarchy (note, amounts in this table indicate carrying values, which approximate fair values): Derivative Financial (In Thousands) Balance at January 1, 2014 $ 4,133 Unrealized gain recognized in earnings 16 Issuances 15,710 Settlements (13,764 ) Balance at December 31, 2014 $ 6,095 Unrealized gain recognized in earnings 47 Issuances 13,281 Settlements (15,394 ) Balance at December 31, 2015 $ 4,029 Non-Recurring Fair Value Measurements ASC 410 “Asset Retirement and Environmental Obligations” addresses financial accounting and reporting for legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal operation. A legal obligation for purposes of ASC 410 is an obligation that a party is required to settle as a result of an existing law, statute, ordinance, written or oral contract or the doctrine of promissory estoppel. IPL’s ARO liabilities relate primarily to environmental issues involving asbestos-containing materials, ash ponds, landfills and miscellaneous contaminants associated with its generating plants, transmission system and distribution system. We use the cost approach to determine the fair value of IPL’s ARO liabilities, which is estimated by discounting expected cash outflows to their present value at the initial recording of the liabilities. Cash outflows are based on the approximate future disposal costs as determined by market information, historical information or other management estimates. These inputs to the fair value of the ARO liabilities would be considered Level 3 inputs under the fair value hierarchy. As of December 31, 2015 and 2014, ARO liabilities were $59.0 million and $59.1 million , respectively. See Note 3, “Utility Plant in Service,” for a rollforward of the ARO liability. Financial Instruments not Measured at Fair Value in the Consolidated Balance Sheets Debt The fair value of our outstanding fixed-rate debt has been determined on the basis of the quoted market prices of the specific securities issued and outstanding. In certain circumstances, the market for such securities was inactive and therefore the valuation was adjusted to consider changes in market spreads for similar securities. Accordingly, the purpose of this disclosure is not to approximate the value on the basis of how the debt might be refinanced. The following table shows the face value and the fair value of fixed-rate and variable-rate indebtedness (Level 2) for the periods ending: December 31, 2015 December 31, 2014 Face Value Fair Value Face Value Fair Value (In Millions) Fixed-rate $ 1,283.4 $ 1,406.8 $ 1,155.3 $ 1,386.2 Variable-rate 256.9 256.9 50.0 50.0 Total indebtedness $ 1,540.3 $ 1,663.7 $ 1,205.3 $ 1,436.2 The difference between the face value and the carrying value of this indebtedness represents unamortized discounts of $4.2 million and $2.9 million at December 31, 2015 and 2014, respectively.

Regulatory Assets And Liabiliti

Regulatory Assets And Liabilities	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Regulatory Assets and Liabilities	REGULATORY ASSETS AND LIABILITIES Regulatory assets represent deferred costs or credits that have been included as allowable costs or credits for ratemaking purposes. IPL has recorded regulatory assets or liabilities relating to certain costs or credits as authorized by the IURC or established regulatory practices in accordance with ASC 980. IPL is amortizing non tax‑related regulatory assets to expense over periods ranging from 1 to 35 years. Tax-related regulatory assets represent the net income tax costs to be considered in future regulatory proceedings generally as the tax-related amounts are paid. The amounts of regulatory assets and regulatory liabilities at December 31 are as follows: 2015 2014 Recovery Period (In Thousands) Regulatory Assets Current: Environmental projects $ 8,002 $ 93 Through 2016 (1) Total current regulatory assets $ 8,002 $ 93 Long-term: Unrecognized pension and other postretirement benefit plan costs $ 226,889 $ 229,590 Various Income taxes recoverable through rates 35,765 31,335 Various Deferred MISO costs 128,610 110,500 To be determined (2) Unamortized Petersburg Unit 4 carrying charges and certain other costs 11,248 12,302 Through 2026 (1) (3) Unamortized reacquisition premium on debt 23,268 24,585 Over remaining life of debt Environmental projects 16,876 7,671 Through 2021 (1) Other miscellaneous 5,544 3,210 To be determined (2) Total long-term regulatory assets $ 448,200 $ 419,193 Total regulatory assets $ 456,202 $ 419,286 Regulatory Liabilities Current: Deferred fuel $ 19,746 $ 17,837 Through 2016 (1) FTRs 4,150 6,235 Through 2016 (1) DSM program costs 4,273 2,001 Through 2016 (1) Environmental projects — 1,870 Through 2016 (1) Total current regulatory liabilities $ 28,169 $ 27,943 Long-term: ARO and accrued asset removal costs $ 637,065 $ 607,628 Not Applicable Unamortized investment tax credit 2,451 3,289 Through 2021 Total long-term regulatory liabilities $ 639,516 $ 610,917 Total regulatory liabilities $ 667,685 $ 638,860 (1) Recovered (credited) per specific rate orders (2) Recovery is probable but timing not yet determined (3) Recovered with a current return Deferred Fuel Deferred fuel costs are a component of current regulatory assets and are expected to be recovered through future FAC proceedings. IPL records deferred fuel in accordance with standards prescribed by the FERC. The deferred fuel adjustment is the result of variances between estimated fuel and purchased power costs in IPL’s FAC and actual fuel and purchased power costs. IPL is generally permitted to recover underestimated fuel and purchased power costs in future rates through the FAC proceedings and therefore the costs are deferred when incurred and amortized into fuel expense in the same period that IPL’s rates are adjusted to reflect these costs. Deferred fuel was a regulatory liability of $19.7 million and $17.8 million as of December 31, 2015 and 2014, respectively. The deferred fuel liability increased $1.9 million in 2015 as a result of IPL charging more for fuel than our actual costs to our jurisdictional customers. Unrecognized Pension and Postretirement Benefit Plan Costs In accordance with ASC 715 “Compensation – Retirement Benefits” and ASC 980, we recognize a regulatory asset equal to the unrecognized actuarial gains and losses and prior service costs. Pension expenses are recorded based on the benefit plan’s actuarially determined pension liability and associated level of annual expenses to be recognized. The other postretirement benefit plan’s deferred benefit cost is the excess of the other postretirement benefit liability over the amount previously recognized. Income Taxes Recoverable Through Rates This amount represents the portion of deferred income taxes that we believe will be recovered through future rates, based upon established regulatory practices, which permit the recovery of current taxes. Accordingly, this regulatory asset is offset by a deferred tax liability and is expected to be recovered, without interest, over the period underlying book-tax timing differences reverse and become current taxes. Deferred MISO Costs These consist of administrative costs for transmission services, transmission expansion cost sharing, and certain other operational and administrative costs from the MISO market. IPL received orders from the IURC that granted authority for IPL to defer such costs and seek recovery in a future basic rate case. Recovery of these costs is believed to be probable, but not certain. See Note 2, “Regulatory Matters.” ARO and Accrued Asset Removal Costs In accordance with ASC 410 and ASC 980, IPL recognizes the cost of removal component of its depreciation reserve that does not have an associated legal retirement obligation as a deferred liability. This amount is net of the portion of legal ARO costs that is currently being recovered in rates.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Regulatory Assets and Liabilities	REGULATORY ASSETS AND LIABILITIES Regulatory assets represent deferred costs or credits that have been included as allowable costs or credits for ratemaking purposes. IPL has recorded regulatory assets or liabilities relating to certain costs or credits as authorized by the IURC or established regulatory practices in accordance with ASC 980. IPL is amortizing non tax‑related regulatory assets to expense over periods ranging from 1 to 35 years. Tax-related regulatory assets represent the net income tax costs to be considered in future regulatory proceedings generally as the tax-related amounts are paid. The amounts of regulatory assets and regulatory liabilities at December 31 are as follows: 2015 2014 Recovery Period (In Thousands) Regulatory Assets Current: Environmental projects $ 8,002 $ 93 Through 2016 (1) Total current regulatory assets $ 8,002 $ 93 Long-term: Unrecognized pension and other postretirement benefit plan costs $ 226,889 $ 229,590 Various Income taxes recoverable through rates 35,765 31,335 Various Deferred MISO costs 128,610 110,500 To be determined (2) Unamortized Petersburg Unit 4 carrying charges and certain other costs 11,248 12,302 Through 2026 (1) (3) Unamortized reacquisition premium on debt 23,268 24,585 Over remaining life of debt Environmental projects 16,876 7,671 Through 2021 (1) Other miscellaneous 5,544 3,210 To be determined (2) Total long-term regulatory assets $ 448,200 $ 419,193 Total regulatory assets $ 456,202 $ 419,286 Regulatory Liabilities Current: Deferred fuel $ 19,746 $ 17,837 Through 2016 (1) FTRs 4,150 6,235 Through 2016 (1) DSM program costs 4,273 2,001 Through 2016 (1) Environmental projects — 1,870 Through 2016 (1) Total current regulatory liabilities $ 28,169 $ 27,943 Long-term: ARO and accrued asset removal costs $ 637,065 $ 607,628 Not Applicable Unamortized investment tax credit 2,451 3,289 Through 2021 Total long-term regulatory liabilities $ 639,516 $ 610,917 Total regulatory liabilities $ 667,685 $ 638,860 (1) Recovered (credited) per specific rate orders (2) Recovery is probable but timing not yet determined (3) Recovered with a current return Deferred Fuel Deferred fuel costs are a component of current regulatory assets and are expected to be recovered through future FAC proceedings. IPL records deferred fuel in accordance with standards prescribed by the FERC. The deferred fuel adjustment is the result of variances between estimated fuel and purchased power costs in IPL’s FAC and actual fuel and purchased power costs. IPL is generally permitted to recover underestimated fuel and purchased power costs in future rates through the FAC proceedings and therefore the costs are deferred when incurred and amortized into fuel expense in the same period that IPL’s rates are adjusted to reflect these costs. Deferred fuel was a regulatory liability of $19.7 million and $17.8 million as of December 31, 2015 and 2014, respectively. The deferred fuel liability increased $1.9 million in 2015 as a result of IPL charging more for fuel than our actual costs to our jurisdictional customers. Unrecognized Pension and Postretirement Benefit Plan Costs In accordance with ASC 715 “Compensation – Retirement Benefits” and ASC 980, we recognize a regulatory asset equal to the unrecognized actuarial gains and losses and prior service costs. Pension expenses are recorded based on the benefit plan’s actuarially determined pension liability and associated level of annual expenses to be recognized. The other postretirement benefit plan’s deferred benefit cost is the excess of the other postretirement benefit liability over the amount previously recognized. Income Taxes Recoverable Through Rates This amount represents the portion of deferred income taxes that we believe will be recovered through future rates, based upon established regulatory practices, which permit the recovery of current taxes. Accordingly, this regulatory asset is offset by a deferred tax liability and is expected to be recovered, without interest, over the period underlying book-tax timing differences reverse and become current taxes. Deferred MISO Costs These consist of administrative costs for transmission services, transmission expansion cost sharing, and certain other operational and administrative costs from the MISO market. IPL received orders from the IURC that granted authority for IPL to defer such costs and seek recovery in a future basic rate case. Recovery of these costs is believed to be probable, but not certain. See Note 2, “Regulatory Matters.” ARO and Accrued Asset Removal Costs In accordance with ASC 410 and ASC 980, IPL recognizes the cost of removal component of its depreciation reserve that does not have an associated legal retirement obligation as a deferred liability. This amount is net of the portion of legal ARO costs that is currently being recovered in rates.

Equity

Equity	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Equity	EQUITY Equity Transactions On December 15, 2014, AES announced that it entered into an agreement with CDPQ, a long-term institutional investor headquartered in Quebec, Canada. Pursuant to the agreement, on February 11, 2015 CDPQ purchased from AES 15% of AES U.S. Investments and 100 shares of IPALCO’s common stock were issued to CDPQ. In addition, CDPQ agreed to invest approximately $349 million in IPALCO through 2016 (of which $214.4 million has been contributed through December 31, 2015), in exchange for a 17.65% equity stake, funding existing growth and environmental projects at IPL. After completion of these transactions, CDPQ’s direct and indirect interests in IPALCO will total approximately 30% , AES will own 85% of AES U.S. Investments, and AES U.S. Investments will own 82.35% of IPALCO. There will be no significant change in management or operational control of AES U.S. Investments, IPALCO or IPL as a result of these transactions. In connection with the initial closing under the agreement, CDPQ, AES U.S. Investments, and IPALCO entered into a Shareholders’ Agreement. The Shareholders’ Agreement established the general framework governing the relationship between and among CDPQ and AES U.S. Investments, and their respective successors and transferees, as shareholders of IPALCO. Pursuant to the Shareholders’ Agreement, the board of directors of IPALCO will initially consist of 11 directors, two nominated by CDPQ and 9 nominated by AES U.S. Investments. The Shareholders’ Agreement contains restrictions on IPALCO making certain major decisions without the prior affirmative vote of a majority of the board of directors of IPALCO. In addition, for so long as CDPQ holds at least 5% of IPALCO’s common shares, CDPQ will have review and consultation rights with respect to certain actions of IPALCO. Certain transfer restrictions and other transfer rights apply to CDPQ and AES U.S. Investments under the Shareholders’ Agreement, including certain rights of first offer, drag along rights, tag along rights, put rights and rights of first refusal. On February 11, 2015, in connection with the initial closing under the Subscription Agreement and the entry into the Shareholders’ Agreement, IPALCO submitted the Third Amended and Restated Articles of Incorporation for filing with the Indiana Secretary of State, as approved and adopted by the IPALCO Board. The purpose of the Third Amended and Restated Articles of Incorporation is to amend, among other things, Article VI of the Second Amended and Restated Articles of Incorporation of IPALCO in order to effectuate changes to the size and composition of the IPALCO Board in furtherance of the terms and conditions of the IPALCO Shareholder’s Agreement. Paid In Capital and Capital Stock On June 27, 2014, and July 31, 2013, IPALCO received equity capital contributions of $106.4 million and $49.1 million , respectively, from AES for funding needs related to IPL’s environmental and replacement generation projects. IPALCO then made the same equity capital contributions to IPL. On April 1, 2015, IPALCO issued and sold 11,818,828 shares of IPALCO's common stock to CDPQ for $214.4 million for funding needs primarily related to IPL's environmental construction program. IPALCO then made the same investment in IPL. As a result of this transaction, CDPQ's direct ownership interest in IPALCO is 11.6% and CDPQ's combined direct and indirect ownership interest in IPALCO is 24.9% . There have been no changes to IPALCO’s capital stock balances during the three years ended December 31, 2015 . Dividend Restrictions IPL’s mortgage and deed of trust and its amended articles of incorporation contain restrictions on IPL’s ability to issue certain securities or pay cash dividends. So long as any of the several series of bonds of IPL issued under its mortgage remains outstanding, and subject to certain exceptions, IPL is restricted in the declaration and payment of dividends, or other distribution on shares of its capital stock of any class, or in the purchase or redemption of such shares, to the aggregate of its net income, as defined in the mortgage, after December 31, 1939. The amount which these mortgage provisions would have permitted IPL to declare and pay as dividends at December 31, 2015 , exceeded IPL’s retained earnings at that date. In addition, pursuant to IPL’s articles, no dividends may be paid or accrued and no other distribution may be made on IPL’s common stock unless dividends on all outstanding shares of IPL preferred stock have been paid or declared and set apart for payment. IPL is also restricted in its ability to pay dividends if it is in default under the terms of its Credit Agreement and its unsecured notes, which could happen if IPL fails to comply with certain covenants. These covenants, among other things, require IPL to maintain a ratio of total debt to total capitalization not in excess of 0.65 to 1 , in order to pay dividends. As of December 31, 2015 and as of the filing of this report, IPL was in compliance with all covenants and no event of default existed. Cumulative Preferred Stock IPL has five separate series of cumulative preferred stock. Holders of preferred stock are entitled to receive dividends at rates per annum ranging from 4.0% to 5.65% . During each year ended December 31, 2015 , 2014 and 2013 , total preferred stock dividends declared were $3.2 million . Holders of preferred stock are entitled to two votes per share for IPL matters, and if four full quarterly dividends are in default on all shares of the preferred stock then outstanding, they are entitled to elect the smallest number of IPL directors to constitute a majority of IPL’s board of directors. Based on the preferred stockholders’ ability to elect a majority of IPL’s board of directors in this circumstance, the redemption of the preferred shares is considered to be not solely within the control of the issuer and the preferred stock was considered temporary equity and presented in the mezzanine level of the audited consolidated balance sheets in accordance with the relevant accounting guidance for non-controlling interests and redeemable securities. IPL has issued and outstanding 500,000 shares of 5.65% preferred stock, which are now redeemable at par value, subject to certain restrictions, in whole or in part. Additionally, IPL has 91,353 shares of preferred stock which are redeemable solely at the option of IPL and can be redeemed in whole or in part at any time at specific call prices. At December 31, 2015 , 2014 and 2013 , preferred stock consisted of the following: December 31, 2015 December 31, Shares Call Price 2015 2014 2013 Par Value, plus premium, if applicable (In Thousands) Cumulative $100 par value, authorized 2,000,000 shares 4% Series 47,611 $ 118.00 $ 5,410 $ 5,410 $ 5,410 4.2% Series 19,331 103.00 1,933 1,933 1,933 4.6% Series 2,481 103.00 248 248 248 4.8% Series 21,930 101.00 2,193 2,193 2,193 5.65% Series 500,000 100.00 50,000 50,000 50,000 Total cumulative preferred stock 591,353 $ 59,784 $ 59,784 $ 59,784
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Equity	EQUITY Paid In Capital and Capital Stock On June 27, 2014, and July 31, 2013, IPALCO received equity capital contributions of $106.4 million and $49.1 million , respectively, from AES for funding needs related to IPL’s environmental and replacement generation projects. IPALCO then made the same equity capital contributions to IPL. On April 1, 2015, IPALCO issued and sold 11,818,828 shares of IPALCO's common stock to CDPQ for $214.4 million for funding needs primarily related to IPL's environmental construction program. IPALCO then made the same investment in IPL. All of the outstanding common stock of IPL is owned by IPALCO. IPL’s common stock is pledged under the 2018 IPALCO Notes and 2020 IPALCO Notes. There have been no changes in the capital stock of IPL during the three years ended December 31, 2015 . Dividend Restrictions IPL’s mortgage and deed of trust and its amended articles of incorporation contain restrictions on IPL’s ability to issue certain securities or pay cash dividends. So long as any of the several series of bonds of IPL issued under its mortgage remains outstanding, and subject to certain exceptions, IPL is restricted in the declaration and payment of dividends, or other distribution on shares of its capital stock of any class, or in the purchase or redemption of such shares, to the aggregate of its net income, as defined in the mortgage, after December 31, 1939. The amount which these mortgage provisions would have permitted IPL to declare and pay as dividends at December 31, 2015 , exceeded IPL’s retained earnings at that date. In addition, pursuant to IPL’s articles, no dividends may be paid or accrued and no other distribution may be made on IPL’s common stock unless dividends on all outstanding shares of IPL preferred stock have been paid or declared and set apart for payment. IPL is also restricted in its ability to pay dividends if it is in default under the terms of its Credit Agreement and its unsecured notes, which could happen if IPL fails to comply with certain covenants. These covenants, among other things, require IPL to maintain a ratio of total debt to total capitalization not in excess of 0.65 to 1 , in order to pay dividends. As of December 31, 2015 and as of the filing of this report, IPL was in compliance with all covenants and no event of default existed. Cumulative Preferred Stock IPL has five separate series of cumulative preferred stock. Holders of preferred stock are entitled to receive dividends at rates per annum ranging from 4.0% to 5.65% . During each year ended December 31, 2015 , 2014 and 2013 , total preferred stock dividends declared were $3.2 million . Holders of preferred stock are entitled to two votes per share for IPL matters, and if four full quarterly dividends are in default on all shares of the preferred stock then outstanding, they are entitled to elect the smallest number of IPL directors to constitute a majority of IPL’s board of directors. Based on the preferred stockholders’ ability to elect a majority of IPL’s board of directors in this circumstance, the redemption of the preferred shares is considered to be not solely within the control of the issuer and the preferred stock was considered temporary equity and presented in the mezzanine level of the audited consolidated balance sheets in accordance with the relevant accounting guidance for non-controlling interests and redeemable securities. IPL has issued and outstanding 500,000 shares of 5.65% preferred stock, which are now redeemable at par value, subject to certain restrictions, in whole or in part. Additionally, IPL has 91,353 shares of preferred stock which are redeemable solely at the option of IPL and can be redeemed in whole or in part at any time at specific call prices. At December 31, 2015 , 2014 and 2013 , preferred stock consisted of the following: December 31, 2015 December 31, Shares Call Price 2015 2014 2013 Par Value, plus premium, if applicable (In Thousands) Cumulative $100 par value, authorized 2,000,000 shares 4% Series 47,611 $ 118.00 $ 5,410 $ 5,410 $ 5,410 4.2% Series 19,331 103.00 1,933 1,933 1,933 4.6% Series 2,481 103.00 248 248 248 4.8% Series 21,930 101.00 2,193 2,193 2,193 5.65% Series 500,000 100.00 50,000 50,000 50,000 Total cumulative preferred stock 591,353 $ 59,784 $ 59,784 $ 59,784

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Debt	DEBT Long-Term Debt The following table presents our long-term debt: December 31, Series Due 2015 2014 (In Thousands) IPL first mortgage bonds (see below): 4.90% (1) January 2016 $ — $ 30,000 4.90% (1) January 2016 — 41,850 4.90% (1) January 2016 — 60,000 5.40% (2) August 2017 24,650 24,650 3.875% (1) August 2021 55,000 55,000 3.875% (1) August 2021 40,000 40,000 4.55% (1) December 2024 40,000 40,000 6.60% January 2034 100,000 100,000 6.05% October 2036 158,800 158,800 6.60% June 2037 165,000 165,000 4.875% November 2041 140,000 140,000 4.65% June 2043 170,000 170,000 4.50% June 2044 130,000 130,000 4.70% September 2045 260,000 — Unamortized discount – net (4,242 ) (2,940 ) Total IPL first mortgage bonds 1,279,208 1,152,360 IPL unsecured debt: Variable (3) December 2020 30,000 — Variable (3) December 2020 60,000 — Total IPL unsecured debt 90,000 — Total Long-term Debt – IPL 1,369,208 1,152,360 Long-term Debt – IPALCO: 7.25% Senior Secured Notes April 2016 — 400,000 5.00% Senior Secured Notes May 2018 400,000 400,000 3.45% Senior Secured Notes July 2020 405,000 — Unamortized discount – net (371 ) (1,347 ) Total Long-term Debt – IPALCO 804,629 798,653 Total Consolidated IPALCO Long-term Debt 2,173,837 1,951,013 Less: Current Portion of Long-term Debt — — Net Consolidated IPALCO Long-term Debt $ 2,173,837 $ 1,951,013 (1) First mortgage bonds are issued to the Indiana Finance Authority, to secure the loan of proceeds from the tax-exempt bonds issued by the Indiana Finance Authority. (2) First mortgage bonds are issued to the city of Petersburg, Indiana, to secure the loan proceeds from various tax-exempt instruments issued by the city. (3) Unsecured notes are issued to the Indiana Finance Authority by IPL to facilitate the loan of proceeds from various tax-exempt notes issued by the Indiana Finance Authority. The notes have a final maturity date of December 2038, but are subject to a mandatory put in December 2020. Debt Maturities Maturities on long-term indebtedness subsequent to December 31, 2015 , are as follows: Year Amount (In Thousands) 2016 $ — 2017 24,650 2018 400,000 2019 — 2020 495,000 Thereafter 1,258,800 Total $ 2,178,450 Significant Transactions IPL First Mortgage Bonds The mortgage and deed of trust of IPL, together with the supplemental indentures thereto, secure the first mortgage bonds issued by IPL. Pursuant to the terms of the mortgage, substantially all property owned by IPL is subject to a first mortgage lien securing indebtedness of $1,283.5 million as of December 31, 2015 . The IPL first mortgage bonds require net earnings as calculated thereunder be at least two and one-half times the annual interest requirements before additional bonds can be authenticated on the basis of property additions. IPL was in compliance with such requirements as of December 31, 2015 . In June 2013, IPL issued $170 million aggregate principal amount of first mortgage bonds, 4.65% Series, due June 2043. Net proceeds from this offering were approximately $167.9 million , after deducting the initial purchasers’ discounts, fees and expenses for the offering payable by IPL. The net proceeds from the offering were used in June 2013 to finance the redemption of $110 million aggregate principal amount of IPL first mortgage bonds, 6.30% Series, due July 2013, and to pay related fees, expenses and applicable redemption prices. We used all remaining proceeds to finance a portion of our environmental construction program and for other general corporate purposes. In June 2014, IPL issued $130 million aggregate principal amount of first mortgage bonds, 4.50% Series, due June 2044. Net proceeds from this offering were approximately $126.8 million , after deducting the initial purchasers’ discounts, fees and expenses for the offering payable by IPL. The net proceeds from the offering were used: (i) to finance a portion of IPL’s construction program; (ii) to finance a portion of IPL’s capital costs related to environmental and replacement generation projects; and (iii) for other general corporate purposes. In September 2015, IPL issued $260 million aggregate principal amount of first mortgage bonds, 4.70% Series, due September 2045, pursuant to Rule 144A and Regulation S under the Securities Act. Net proceeds from this offering were approximately $255.6 million , after deducting the initial purchasers’ discounts and fees and expenses for the offering payable by IPL. The net proceeds from the offering were used to finance a portion of IPL's construction program and capital costs related to environmental and replacement generation projects and for other general corporate purposes. In December 2015, IPL refunded $131.9 million aggregate principal amount of first mortgage bonds, 4.90% Series, due January 2016 from the proceeds of unsecured notes with a syndication of banks. For further discussion, please see “ – IPL Unsecured Notes” below. IPL Unsecured Notes In October 2015, IPL entered into an unsecured $91.9 million 364 -day committed credit facility with a delayed draw feature at variable rates with a syndication of banks. It was drawn on in October and December 2015 to fund the October 2015 termination of IPL’s $50 million accounts receivable securitization program and to assist in the December 2015 refunding of $41.9 million of IPL's outstanding aggregate principal amount of 4.90% Environmental Facilities Refunding Revenue Bonds (Indianapolis Power & Light Company Project) Series 2009A due in January 2016. This agreement matures on October 14, 2016, and bears interest at variable rates as described in the credit agreement. This credit facility contain customary representations, warranties and covenants, including a leverage covenant consistent with the leverage covenant contained in IPL's Credit Agreement. In December 2015, the Indiana Finance Authority issued on behalf of IPL an aggregate principal amount of $90 million of Environmental Facilities Refunding Revenue Notes due December 2038 (Indianapolis Power & Light Company Project). These unsecured notes were issued in two series: $30 million Series 2015A notes and $60 million 2015B notes. These notes were initially purchased by a syndication of banks who will hold the notes until the mandatory put date of December 22, 2020. The proceeds of the 2015A notes and the 2015B notes were loaned to IPL to assist it in refunding the $30 million Indiana Finance Authority Environmental Facilities Refunding Revenue Bonds (Indianapolis Power & Light Company Project) Series 2009B and $60 million Indiana Finance Authority Environmental Facilities Refunding Revenue Bonds (Indianapolis Power & Light Company Project) Series 2009C each series due January 1, 2016. These notes bear interest at a variable rate as described in the notes purchase and covenants agreement. The agreement contains customary representations, warranties and covenants, including a leverage covenant consistent with the leverage covenant contained in IPL's Credit Agreement. IPALCO’s Senior Secured Notes In June 2015, IPALCO completed the sale of the 2020 IPALCO Notes pursuant to Rule 144A and Regulation S under the Securities Act. The 2020 IPALCO Notes were issued pursuant to an Indenture dated June 25, 2015, by and between IPALCO and U.S. Bank, National Association, as trustee. The 2020 IPALCO Notes were priced to the public at 99.929% of the principal amount. Net proceeds to IPALCO were approximately $399.5 million after deducting underwriting costs and estimated offering expenses. These costs are being amortized to the maturity date using the effective interest method. We used the net proceeds from this offering to fund the purchase of the 2016 IPALCO Notes validly tendered and to pay for a related consent solicitation, to redeem any 2016 IPALCO Notes that remained outstanding after the completion of the tender, and to pay certain related fees, expenses and make-whole premiums. Of the 2016 IPALCO Notes outstanding, $366.5 million were tendered in June 2015. The remainder, $33.5 million , was redeemed in July 2015. An early tender premium was paid related to the tender offer and a redemption premium was paid related to the redemption of the 2016 IPALCO Notes. A loss on early extinguishment of debt of $22.1 million for the 2016 IPALCO Notes is included as a separate line item within “ Other Income and (Deductions) ” in the accompanying Consolidated Statements of Operations. The 2020 IPALCO Notes are secured by IPALCO's pledge of all of the outstanding common stock of IPL. The lien on the pledged shares is shared equally and ratably with IPALCO's existing senior secured notes. IPALCO has entered into a Pledge Agreement Supplement with the Bank of New York Mellon Trust Company, N.A., as Collateral Agent, dated June 25, 2015, to the Pledge Agreement between IPALCO and The Bank of New York Mellon Trust Company, N.A., dated November 14, 2001, as supplemented by a Pledge Agreement Supplement dated April 15, 2008 and a Pledge Agreement Supplement dated May 18, 2011, each by IPALCO in favor of the Collateral Agent. IPALCO also agreed to register the 2020 IPALCO Notes under the Securities Act by filing an exchange offer registration statement or, under specified circumstances, a shelf registration statement with the SEC pursuant to a Registration Rights Agreement that IPALCO entered into with J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC, as representatives of the initial purchasers of the 2020 IPALCO Notes. IPALCO filed its registration statement on Form S-4 with respect to the 2020 IPALCO Notes with the SEC on September 28, 2015, and this registration statement was declared effective on October 15, 2015. The exchange offer was completed on November 16, 2015. The 2018 IPALCO Notes and 2020 IPALCO Notes are secured by IPALCO’s pledge of all of the outstanding common stock of IPL. Line of Credit IPL entered into an amendment and restatement of its 5 -year $250 million revolving credit facility in May 2014, and a further amendment and extension of the credit facility on October 16, 2015 (the “Credit Agreement”) with a syndication of banks. This Credit Agreement is an unsecured committed line of credit to be used: (i) to finance capital expenditures; (ii) to refinance indebtedness under the existing credit agreement; (iii) to support working capital; and (iv) for general corporate purposes. This agreement matures on October 16, 2020, and bears interest at variable rates as described in the Credit Agreement. It includes an uncommitted $150 million accordion feature to provide IPL with an option to request an increase in the size of the facility at any time prior to October 16, 2019, subject to approval by the lenders. Prior to execution, IPL and IPALCO had existing general banking relationships with the parties in this agreement. As of December 31, 2015 and 2014 , IPL had $75.0 million and $0 million in outstanding borrowings on the committed line of credit, respectively. Restrictions on Issuance of Debt All of IPL’s long-term borrowings must first be approved by the IURC and the aggregate amount of IPL’s short-term indebtedness must be approved by the FERC. IPL has approval from FERC to borrow up to $500 million of short-term indebtedness outstanding at any time through July 28, 2016. In December 2015, IPL received an order from the IURC granting IPL authority through December 31, 2018 to, among other things, issue up to $650 million in aggregate principal amount of long-term debt (inclusive of $260 million of first mortgage bonds issued in September 2015), refinance up to $196.5 million in existing indebtedness (inclusive of $90 million of unsecured notes issued in December 2015), have up to $500 million of long-term credit agreements and liquidity facilities outstanding at any one time, and, as an alternative to the sale of all or a portion of $65 million in principal amount of the long-term debt mentioned above, issue up to $65 million of new preferred stock. IPL also has restrictions on the amount of new debt that may be issued due to contractual obligations of AES and by financial covenant restrictions under our existing debt obligations. Under such restrictions, IPL is generally allowed to fully draw the amounts available on its credit facility, refinance existing debt and issue new debt approved by the IURC and issue certain other indebtedness. Credit Ratings Our ability to borrow money or to refinance existing indebtedness and the interest rates at which we can borrow money or refinance existing indebtedness are affected by our credit ratings. In addition, the applicable interest rates on IPL’s Credit Agreement and other unsecured notes (as well as the amount of certain other fees on the Credit Agreement and the 364-day unsecured notes) are dependent upon the credit ratings of IPL. Downgrades in the credit ratings of AES could result in IPL’s and/or IPALCO’s credit ratings being downgraded. Accounts Receivable Securitization IPL formed IPL Funding in 1996 as a special-purpose entity to purchase receivables originated by IPL pursuant to a receivables purchase agreement between IPL and IPL Funding. IPL Funding also entered into a sale facility as defined in the Receivables Sale Agreement, which matured as extended on October 24, 2012. At that time, the Purchasers replaced The Royal Bank of Scotland plc and Windmill Funding Corporation as Agent and Investor, respectively. On October 20, 2014, Citibank, as the sole Liquidity Provider, and CRC Funding entered into a Transfer Supplement pursuant to which Citibank assigned to CRC Funding, and CRC Funding assumed, all of Citibank’s Commitment and Purchase Interest, and accordingly, CRC Funding was both the Investor and a Liquidity Provider, referred to as the “Purchaser.” Pursuant to the terms of the Receivables Sale Agreement, the Purchasers agree to purchase from IPL Funding, on a revolving basis, interests in the pool of receivables purchased from IPL up to the lesser of (1) an amount determined pursuant to the sale facility that took into account certain eligibility requirements and reserves relating to the receivables, or (2) $50 million . That amount was $0 million and $50 million as of December 31, 2015 and 2014, respectively. As collections reduce accounts receivable included in the pool, IPL Funding sells ownership interests in additional receivables acquired from IPL to return the ownership interests sold to the maximum amount permitted by the sale facility. IPL Funding is included in the Consolidated Financial Statements of IPALCO. On October 16, 2015, IPL closed on a new unsecured $91.9 million 364 -day committed credit facility with a syndication of banks. The first $50 million of the term loan was drawn at closing to fund the October 19, 2015 termination of IPL's $50 million accounts receivable securitization program. Please see “ – IPL Unsecured Notes ” above for details.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Debt	. DEBT Long-Term Debt The following table presents our long-term debt: December 31, Series Due 2015 2014 (In Thousands) IPL first mortgage bonds (see below): 4.90% (1) January 2016 $ — $ 30,000 4.90% (1) January 2016 — 41,850 4.90% (1) January 2016 — 60,000 5.40% (2) August 2017 24,650 24,650 3.875% (1) August 2021 55,000 55,000 3.875% (1) August 2021 40,000 40,000 4.55% (1) December 2024 40,000 40,000 6.60% January 2034 100,000 100,000 6.05% October 2036 158,800 158,800 6.60% June 2037 165,000 165,000 4.875% November 2041 140,000 140,000 4.65% June 2043 170,000 170,000 4.50% June 2044 130,000 130,000 4.70% September 2045 260,000 — Unamortized discount – net (4,242 ) (2,940 ) Total IPL first mortgage bonds 1,279,208 1,152,360 IPL unsecured debt: Variable (3) December 2020 30,000 — Variable (3) December 2020 60,000 — Total IPL unsecured debt 90,000 — Total Consolidated IPL Long-term Debt 1,369,208 1,152,360 Less: Current Portion of Long-term Debt — — Net Consolidated IPL Long-term Debt $ 1,369,208 $ 1,152,360 (1) First mortgage bonds are issued to the Indiana Finance Authority, to secure the loan of proceeds from the tax-exempt bonds issued by the Indiana Finance Authority. (2) First mortgage bonds are issued to the city of Petersburg, Indiana, to secure the loan proceeds from various tax-exempt instruments issued by the city. (3) Unsecured notes are issued to the Indiana Finance Authority by IPL to facilitate the loan of proceeds from various tax-exempt notes issued by the Indiana Finance Authority. The notes have a final maturity date of December 2038, but are subject to a mandatory put in December 2020. Debt Maturities Maturities on long-term indebtedness subsequent to December 31, 2015 , are as follows: Year Amount (In Thousands) 2016 $ — 2017 24,650 2018 — 2019 — 2020 90,000 Thereafter 1,258,800 Total $ 1,373,450 Significant Transactions IPL First Mortgage Bonds The mortgage and deed of trust of IPL, together with the supplemental indentures thereto, secure the first mortgage bonds issued by IPL. Pursuant to the terms of the mortgage, substantially all property owned by IPL is subject to a first mortgage lien securing indebtedness of $1,283.5 million as of December 31, 2015 . The IPL first mortgage bonds require net earnings as calculated thereunder be at least two and one-half times the annual interest requirements before additional bonds can be authenticated on the basis of property additions. IPL was in compliance with such requirements as of December 31, 2015 . In June 2013, IPL issued $170 million aggregate principal amount of first mortgage bonds, 4.65% Series, due June 2043. Net proceeds from this offering were approximately $167.9 million , after deducting the initial purchasers’ discounts, fees and expenses for the offering payable by IPL. The net proceeds from the offering were used in June 2013 to finance the redemption of $110 million aggregate principal amount of IPL first mortgage bonds, 6.30% Series, due July 2013, and to pay related fees, expenses and applicable redemption prices. We used all remaining proceeds to finance a portion of our environmental construction program and for other general corporate purposes. In June 2014, IPL issued $130 million aggregate principal amount of first mortgage bonds, 4.50% Series, due June 2044. Net proceeds from this offering were approximately $126.8 million , after deducting the initial purchasers’ discounts, fees and expenses for the offering payable by IPL. The net proceeds from the offering were used: (i) to finance a portion of IPL’s construction program; (ii) to finance a portion of IPL’s capital costs related to environmental and replacement generation projects; and (iii) for other general corporate purposes. In September 2015, IPL issued $260 million aggregate principal amount of first mortgage bonds, 4.70% Series, due September 2045, pursuant to Rule 144A and Regulation S under the Securities Act. Net proceeds from this offering were approximately $255.6 million , after deducting the initial purchasers’ discounts and fees and expenses for the offering payable by IPL. The net proceeds from the offering were used to finance a portion of IPL's construction program and capital costs related to environmental and replacement generation projects and for other general corporate purposes. In December 2015, IPL refunded $131.9 million aggregate principal amount of first mortgage bonds, 4.90% Series, due January 2016 from the proceeds of unsecured notes with a syndication of banks. For further discussion, please see “ – IPL Unsecured Notes” below. IPL Unsecured Notes In October 2015, IPL entered into an unsecured $91.9 million 364 -day committed credit facility with a delayed draw feature at variable rates with a syndication of banks. It was drawn on in October and December 2015 to fund the October 2015 termination of IPL’s $50 million accounts receivable securitization program and to assist in the December 2015 refunding of $41.9 million of IPL's outstanding aggregate principal amount of 4.90% Environmental Facilities Refunding Revenue Bonds (Indianapolis Power & Light Company Project) Series 2009A due in January 2016. This agreement matures on October 14, 2016, and bears interest at variable rates as described in the credit agreement. This credit facility contain customary representations, warranties and covenants, including a leverage covenant consistent with the leverage covenant contained in IPL's Credit Agreement. In December 2015, the Indiana Finance Authority issued on behalf of IPL an aggregate principal amount of $90 million of Environmental Facilities Refunding Revenue Notes due December 2038 (Indianapolis Power & Light Company Project). These unsecured notes were issued in two series: $30 million Series 2015A notes and $60 million 2015B notes. These notes were initially purchased by a syndication of banks who will hold the notes until the mandatory put date of December 22, 2020. The proceeds of the 2015A notes and the 2015B notes were loaned to IPL to assist it in refunding the $30 million Indiana Finance Authority Environmental Facilities Refunding Revenue Bonds (Indianapolis Power & Light Company Project) Series 2009B and $60 million Indiana Finance Authority environmental Facilities Refunding Revenue Bonds (Indianapolis Power & Light Company Project) Series 2009C each series due January 1, 2016. These notes bear interest at a variable rate as described in the notes purchase and covenants agreement. The agreement contains customary representations, warranties and covenants, including a leverage covenant consistent with the leverage covenant contained in IPL's Credit Agreement. Line of Credit IPL entered into an amendment and restatement of its 5 -year $250 million revolving credit facility in May 2014, and a further amendment and extension of the credit facility on October 16, 2015 (the “Credit Agreement”) with a syndication of banks. This Credit Agreement is an unsecured committed line of credit to be used: (i) to finance capital expenditures; (ii) to refinance indebtedness under the existing credit agreement; (iii) to support working capital; and (iv) for general corporate purposes. This agreement matures on October 16, 2020, and bears interest at variable rates as described in the Credit Agreement. It includes an uncommitted $150 million accordion feature to provide IPL with an option to request an increase in the size of the facility at any time prior to October 16, 2019, subject to approval by the lenders. Prior to execution, IPL had existing general banking relationships with the parties in this agreement. As of December 31, 2015 and 2014, IPL had $75.0 million and $0 million in outstanding borrowings on the committed line of credit, respectively. Restrictions on Issuance of Debt All of IPL’s long-term borrowings must first be approved by the IURC and the aggregate amount of IPL’s short-term indebtedness must be approved by the FERC. IPL has approval from FERC to borrow up to $500 million of short-term indebtedness outstanding at any time through July 28, 2016. In December 2015, IPL received an order from the IURC granting IPL, authority through December 31, 2018 to, among other things, issue up to $650 million in aggregate principal amount of long-term debt (inclusive of $260 million of first mortgage bonds issued in September 2015), refinance up to $196.5 million in existing indebtedness (inclusive of $90 million of unsecured notes issued in December 2015), have up to $500 million of long-term credit agreements and liquidity facilities outstanding at any one time, and, as an alternative to the sale of all or a portion of $65 million in principal amount of the long-term debt mentioned above, issue up to $65 million of new preferred stock. IPL also has restrictions on the amount of new debt that may be issued due to contractual obligations of AES and by financial covenant restrictions under our existing debt obligations. Under such restrictions, IPL is generally allowed to fully draw the amounts available on its credit facility, refinance existing debt and issue new debt approved by the IURC and issue certain other indebtedness. Credit Ratings Our ability to borrow money or to refinance existing indebtedness and the interest rates at which we can borrow money or refinance existing indebtedness are affected by our credit ratings. In addition, the applicable interest rates on IPL’s Credit Agreement and other unsecured notes (as well as the amount of certain other fees on the Credit Agreement and the 364-day unsecured notes) are dependent upon the credit ratings of IPL. Downgrades in the credit ratings of AES and/or IPALCO could result in IPL’s credit ratings being downgraded. Accounts Receivable Securitization IPL formed IPL Funding in 1996 as a special-purpose entity to purchase receivables originated by IPL pursuant to a receivables purchase agreement between IPL and IPL Funding. IPL Funding also entered into a sale facility as defined in the Receivables Sale Agreement, which matured as extended on October 24, 2012. At that time, the Purchasers replaced The Royal Bank of Scotland plc and Windmill Funding Corporation as Agent and Investor, respectively. On October 20, 2014, Citibank, as the sole Liquidity Provider, and CRC Funding entered into a Transfer Supplement pursuant to which Citibank assigned to CRC Funding, and CRC Funding assumed, all of Citibank’s Commitment and Purchase Interest, and accordingly, CRC Funding was both the Investor and a Liquidity Provider, referred to as the “Purchaser.” Pursuant to the terms of the Receivables Sale Agreement, the Purchasers agree to purchase from IPL Funding, on a revolving basis, interests in the pool of receivables purchased from IPL up to the lesser of (1) an amount determined pursuant to the sale facility that took into account certain eligibility requirements and reserves relating to the receivables, or (2) $50 million . That amount was $0 million and $50 million as of December 31, 2015 and 2014, respectively. As collections reduce accounts receivable included in the pool, IPL Funding sells ownership interests in additional receivables acquired from IPL to return the ownership interests sold to the maximum amount permitted by the sale facility. IPL Funding is included in the Consolidated Financial Statements of IPL. On October 16, 2015, IPL closed on a new unsecured $91.9 million 364 -day committed credit facility with a syndication of banks. The first $50 million of the term loan was drawn at closing to fund the October 19, 2015 termination of IPL's $50 million accounts receivable securitization program. Please see “ – IPL Unsecured Notes ” above for details.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Income Taxes	INCOME TAXES IPALCO follows a policy of comprehensive interperiod income tax allocation. Investment tax credits related to utility property have been deferred and are being amortized over the estimated useful lives of the related property. AES files federal and state income tax returns which consolidate IPALCO and its subsidiaries. Under a tax sharing agreement with AES, IPALCO is responsible for the income taxes associated with its own taxable income and records the provision for income taxes as if IPALCO and its subsidiaries each filed separate income tax returns. IPALCO is no longer subject to U.S. or state income tax examinations for tax years through March 27, 2001, but is open for all subsequent periods. On March 25, 2014, the State of Indiana amended Indiana Code 6-3-2-1 through Senate Bill 001, which phases in an additional 1.6% reduction to the state corporate income tax rate that was initially being reduced by 2% . While the statutory state income tax rate remained at 6.75% for the calendar year 2015, the deferred tax balances were adjusted according to the anticipated reversal of temporary differences. The change in required deferred taxes on plant and plant-related temporary differences resulted in a reduction to the associated regulatory asset of $1.0 million . The change in required deferred taxes on non-property related temporary differences which are not probable to cause a reduction in future base customer rates resulted in a tax benefit of $0.4 million . On September 13, 2013, the Internal Revenue Service released final regulations addressing the acquisition, production and improvement of tangible property and proposed regulations addressing the disposition of property. These regulations replace previously issued temporary regulations and are effective for tax years beginning on or after January 1, 2014. IPL management has opted to fully implement the new regulations effective with its 2014 income tax return. IPL has recorded the tax effect of a $245.9 million favorable Internal Revenue Code Section 481(a) adjustment to its balance sheet as a result of the regulations. This amount represents the cumulative effective of accelerated deductions related to repairs of tangible property through December 31, 2013. The adjustment does not impact the income statement. Internal Revenue Code Section 199 permits taxpayers to claim a deduction from taxable income attributable to certain domestic production activities. IPL’s electric production activities qualify for this deduction. Beginning in 2010 and thereafter, the deduction is equal to 9% of the taxable income attributable to qualifying production activity. There was no tax benefit associated with the Internal Revenue Code Section 199 domestic production deduction for tax years 2015 and 2014 , primarily due to the election of the final tangible property regulations. The tax benefit associated with tax year 2013 was $3.7 million . In 2015, IPALCO elected to early adopt ASU No. 2015-17, “ Balance Sheet Classification of Deferred Taxes ,” under the prospective method. To simplify presentation of deferred income taxes, ASU 2015-17 requires that deferred tax liabilities and assets be classified as non-current in a statement of financial position, removing the previous requirement to report both current and non-current deferred tax liabilities and assets separately. By early adopting under the prospective method, previous reporting periods have not been retrospectively adjusted. Income Tax Provision Federal and state income taxes charged to income are as follows: 2015 2014 2013 (In Thousands) Charged to utility operating expenses: Current income taxes: Federal $ 18,661 $ 944 $ 53,937 State 5,758 110 15,191 Total current income taxes 24,419 1,054 69,128 Deferred income taxes: Federal 29,165 58,114 (8,048 ) State 5,019 12,498 (1,031 ) Total deferred income taxes 34,184 70,612 (9,079 ) Net amortization of investment credit (1,319 ) (1,431 ) (1,501 ) Total charge to utility operating expenses 57,284 70,235 58,548 Charged to other income and deductions: Current income taxes: Federal (18,661 ) (459 ) (16,909 ) State (5,758 ) (5 ) (4,193 ) Total current income taxes (24,419 ) (464 ) (21,102 ) Deferred income taxes: Federal (2,573 ) (18,082 ) 246 State 1,274 (3,645 ) 50 Total deferred income taxes (1,299 ) (21,727 ) 296 Net provision to other income and deductions (25,718 ) (22,191 ) (20,806 ) Total federal and state income tax provisions $ 31,566 $ 48,044 $ 37,742 Effective and Statutory Rate Reconciliation The provision for income taxes (including net investment tax credit adjustments) is different than the amount computed by applying the statutory tax rate to pretax income. The reasons for the difference, stated as a percentage of pretax income, are as follows: 2015 2014 2013 Federal statutory tax rate 35.0 % 35.0 % 35.0 % State income tax, net of federal tax benefit 4.7 % 4.8 % 6.7 % Amortization of investment tax credits (1.5 )% (1.2 )% (1.5 )% Preferred dividends of subsidiary 1.3 % 0.9 % 1.1 % Depreciation flow through and amortization (0.3 )% (0.3 )% (0.3 )% Additional funds used during construction - equity (3.5 )% (0.3 )% 0.6 % Manufacturers’ Production Deduction (Sec. 199) — % — % (3.8 )% Other – net 0.2 % 0.2 % 0.5 % Effective tax rate 35.9 % 39.1 % 38.3 % Deferred Income Taxes The significant items comprising IPALCO’s net accumulated deferred tax liability recognized on the audited Consolidated Balance Sheets as of December 31, 2015 and 2014 , are as follows: 2015 2014 (In Thousands) Deferred tax liabilities: Relating to utility property, net $ 541,369 $ 539,318 Regulatory assets recoverable through future rates 178,187 161,697 Other 11,768 14,211 Total deferred tax liabilities 731,324 715,226 Deferred tax assets: Investment tax credit 1,507 2,019 Regulatory liabilities including ARO 260,555 247,118 Employee benefit plans 38,159 45,091 Net operating loss 23,161 51,364 Other 10,548 10,289 Total deferred tax assets 333,930 355,881 Net deferred tax liability 397,394 359,345 Less: deferred tax asset - current — (61,782 ) Deferred income taxes – net $ 397,394 $ 421,127 Uncertain Tax Positions The following is a reconciliation of the beginning and ending amounts of unrecognized tax benefits for the years ended December 31, 2015 , 2014 and 2013 : 2015 2014 2013 (In Thousands) Unrecognized tax benefits at January 1 $ 7,042 $ 6,734 $ 6,138 Gross increases – current period tax positions 962 975 986 Gross decreases – prior period tax positions (857 ) (667 ) (390 ) Unrecognized tax benefits at December 31 $ 7,147 $ 7,042 $ 6,734 The unrecognized tax benefits at December 31, 2015 represent tax positions for which the ultimate deductibility is highly certain but for which there is uncertainty about the timing of such deductibility. Because of the impact of deferred tax accounting, other than interest and penalties, the timing of the deductions will not affect the annual effective tax rate but would accelerate the tax payments to an earlier period. Tax-related interest expense and income is reported as part of the provision for federal and state income taxes. Penalties, if incurred, would also be recognized as a component of tax expense. There are no interest or penalties applicable to the periods contained in this report.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Income Taxes	INCOME TAXES IPL follows a policy of comprehensive interperiod income tax allocation. Investment tax credits related to utility property have been deferred and are being amortized over the estimated useful lives of the related property. AES files federal and state income tax returns which consolidate IPALCO and IPL. Under a tax sharing agreement with IPALCO, IPL is responsible for the income taxes associated with its own taxable income and records the provision for income taxes as if IPL filed separate income tax returns. IPL is no longer subject to U.S. or state income tax examinations for tax years through March 27, 2001, but is open for all subsequent periods. On March 25, 2014, the State of Indiana amended Indiana Code 6-3-2-1 through Senate Bill 001, which phases in an additional 1.6% reduction to the state corporate income tax rate that was initially being reduced by 2% . While the statutory state income tax rate remained at 6.75% for the calendar year 2015, the deferred tax balances were adjusted according to the anticipated reversal of temporary differences. The change in required deferred taxes on plant and plant-related temporary differences resulted in a reduction to the associated regulatory asset of $1.0 million . The change in required deferred taxes on non-property related temporary differences which are not probable to cause a reduction in future base customer rates resulted in a tax benefit of $0.4 million . On September 13, 2013, the Internal Revenue Service released final regulations addressing the acquisition, production and improvement of tangible property and proposed regulations addressing the disposition of property. These regulations replace previously issued temporary regulations and are effective for tax years beginning on or after January 1, 2014. IPL management has opted to fully implement the new regulations effective with its 2014 income tax return. IPL has recorded the tax effect of a $245.9 million favorable Internal Revenue Code Section 481(a) adjustment to its balance sheet as a result of the regulations. This amount represents the cumulative effective of accelerated deductions related to repairs of tangible property through December 31, 2013. The adjustment does not impact the income statement. Internal Revenue Code Section 199 permits taxpayers to claim a deduction from taxable income attributable to certain domestic production activities. IPL’s electric production activities qualify for this deduction. Beginning in 2010 and thereafter, the deduction is equal to 9% of the taxable income attributable to qualifying production activity. The tax benefit associated with the Internal Revenue Code Section 199 domestic production deduction for 2015 , 2014 and 2013 was $1.7 million , $0.0 million , and $4.4 million , respectively. There was no tax benefit for 2014 primarily due to the election of the final tangible property regulations. In 2015, IPL elected to early adopt ASU No. 2015-17, “ Balance Sheet Classification of Deferred Taxes ,” under the prospective method. To simplify presentation of deferred income taxes, ASU 2015-17 requires that deferred tax liabilities and assets be classified as non-current in a statement of financial position, removing the previous requirement to report both current and non-current deferred tax liabilities and assets separately. By early adopting under the prospective method, previous reporting periods have not been retrospectively adjusted. Income Tax Provision Federal and state income taxes charged to income are as follows: 2015 2014 2013 (In Thousands) Charged to utility operating expenses: Current income taxes: Federal $ 18,661 $ 944 $ 53,937 State 5,758 110 15,191 Total current income taxes 24,419 1,054 69,128 Deferred income taxes: Federal 29,165 58,114 (8,048 ) State 5,019 12,498 (1,031 ) Total deferred income taxes 34,184 70,612 (9,079 ) Net amortization of investment credit (1,319 ) (1,431 ) (1,501 ) Total charge to utility operating expenses 57,284 70,235 58,548 Charged to other income and deductions: Current income taxes: Federal (1,715 ) 329 (752 ) State (240 ) 69 (62 ) Total current income taxes (1,955 ) 398 (814 ) Deferred income taxes: Federal 740 (1,202 ) (13 ) State 150 (148 ) (1 ) Total deferred income taxes 890 (1,350 ) (14 ) Net provision to other income and deductions (1,065 ) (952 ) (828 ) Total federal and state income tax provisions $ 56,219 $ 69,283 $ 57,720 Effective and Statutory Rate Reconciliation The provision for income taxes (including net investment tax credit adjustments) is different than the amount computed by applying the statutory tax rate to pretax income. The reasons for the difference, stated as a percentage of pretax income, are as follows: 2015 2014 2013 Federal statutory tax rate 35.0 % 35.0 % 35.0 % State income tax, net of federal tax benefit 4.4 % 4.6 % 6.0 % Amortization of investment tax credits (0.8 )% (0.8 )% (1.0 )% Depreciation flow through and amortization (0.2 )% (0.2 )% (0.2 )% Additional funds used during construction - equity (1.9 )% (0.2 )% 0.4 % Manufacturers’ Production Deduction (Sec. 199) (1.0 )% — % (3.2 )% Other – net 0.1 % 0.4 % 0.4 % Effective tax rate 35.6 % 38.8 % 37.4 % Deferred Income Taxes The significant items comprising IPL’s net accumulated deferred tax liability recognized on the audited Consolidated Balance Sheets as of December 31, 2015 and 2014 , are as follows: 2015 2014 (In Thousands) Deferred tax liabilities: Relating to utility property, net $ 541,369 $ 539,318 Regulatory assets recoverable through future rates 178,187 161,697 Other 11,349 13,885 Total deferred tax liabilities 730,905 714,900 Deferred tax assets: Investment tax credit 1,507 2,019 Regulatory liabilities including ARO 260,555 247,118 Employee benefit plans 38,159 45,090 Net operating loss — 31,172 Other 10,953 10,008 Total deferred tax assets 311,174 335,407 Net deferred tax liability 419,731 379,493 Less: deferred tax asset - current — (41,551 ) Deferred income taxes – net $ 419,731 $ 421,044 Uncertain Tax Positions The following is a reconciliation of the beginning and ending amounts of unrecognized tax benefits for the years ended December 31, 2015 , 2014 and 2013 : 2015 2014 2013 (In Thousands) Unrecognized tax benefits at January 1 $ 7,042 $ 6,734 $ 6,138 Gross increases – current period tax positions 962 975 986 Gross decreases – prior period tax positions (857 ) (667 ) (390 ) Unrecognized tax benefits at December 31 $ 7,147 $ 7,042 $ 6,734 The unrecognized tax benefits at December 31, 2015 represent tax positions for which the ultimate deductibility is highly certain but for which there is uncertainty about the timing of such deductibility. Because of the impact of deferred tax accounting, other than interest and penalties, the timing of the deductions will not affect the annual effective tax rate but would accelerate the tax payments to an earlier period. Tax-related interest expense and income is reported as part of the provision for federal and state income taxes. Penalties, if incurred, would also be recognized as a component of tax expense. There are no interest or penalties applicable to the periods contained in this report.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Benefit Plans	BENEFIT PLANS Defined Contribution Plans All of IPL’s employees are covered by one of two defined contribution plans, the Thrift Plan or the RSP: The Thrift Plan Approximately 84% of IPL’s active employees are covered by the Thrift Plan, a qualified defined contribution plan. All union new hires are covered under the Thrift Plan. Participants elect to make contributions to the Thrift Plan based on a percentage of their base compensation. Each participant’s contribution is matched up to certain thresholds of base compensation. The IBEW clerical-technical union new hires receive an annual lump sum company contribution into the Thrift Plan in addition to the company match. Employer contributions to the Thrift Plan were $3.1 million , $3.0 million and $3.0 million for 2015 , 2014 and 2013 , respectively. The RSP Approximately 16% of IPL’s active employees are covered by the RSP, a qualified defined contribution plan containing a profit sharing component. All non-union new hires are covered under the RSP. Participants elect to make contributions to the RSP based on a percentage of their taxable compensation. Each participant’s contribution is matched in amounts up to, but not exceeding, 5% of the participant’s taxable compensation. In addition, the RSP has a profit sharing component whereby IPL contributes a percentage of each employee’s annual salary into the plan on a pre-tax basis. The profit sharing percentage is determined by the AES board of directors on an annual basis. Employer payroll-matching and profit sharing contributions (by IPL) relating to the RSP were $0.3 million , $1.5 million and $1.8 million for 2015 , 2014 and 2013 , respectively. The decrease in the 2015 net contributions is a result of truing up prior year estimated profit sharing contributions. Defined Benefit Plans Approximately 77% of IPL’s active employees are covered by the qualified Defined Benefit Pension Plan; while approximately 7% of active employees are IBEW clerical-technical unit employees who are only eligible for the Thrift Plan, which is a defined contribution plan. The remaining 16% of active employees are covered by the RSP. The RSP is a qualified defined contribution plan containing a profit sharing component. All non-union new hires are covered under the RSP, while IBEW physical unit union new hires are covered under the Defined Benefit Pension Plan and Thrift Plan. The IBEW clerical-technical unit new hires are no longer covered under the Defined Benefit Pension Plan but do receive an annual lump sum company contribution into the Thrift Plan, in addition to the company match. The Defined Benefit Pension Plan is noncontributory and is funded by IPL through a trust. Effective April 1, 2015, benefits for non-union participants in the Defined Benefit Pension Plan are based on salary and years of service. Benefits for eligible union participants are based on each individual employee's pension band and years of service as opposed to their compensation. Pension bands are based primarily on job duties and responsibilities. Additionally, a small group of former officers and their surviving spouses are covered under a funded non-qualified Supplemental Retirement Plan. The total number of participants in the plan as of December 31, 2015 was 24 . The plan is closed to new participants. IPL also provides postretirement health care benefits to certain active or retired employees and the spouses of certain active or retired employees. Approximately 171 active employees and 27 retirees (including spouses) were receiving such benefits or entitled to future benefits as of January 1, 2015. The plan is unfunded. These postretirement health care benefits and the related obligation were not material to the consolidated financial statements in the periods covered by this report. The following table presents information relating to the Pension Plans: Pension benefits 2015 2014 (In Thousands) Change in benefit obligation: Projected benefit obligation at January 1 $ 748,421 $ 650,713 Service cost 8,314 7,231 Interest cost 29,638 31,154 Actuarial (gain) loss (31,989 ) 90,693 Amendments (primarily increases in pension bands) 5,409 1,233 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Projected benefit obligation at December 31 723,887 748,421 Change in plan assets: Fair value of plan assets at January 1 657,239 561,586 Actual return on plan assets 1,074 74,147 Employer contributions 25,166 54,109 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Fair value of plan assets at December 31 647,573 657,239 Unfunded status $ (76,314 ) $ (91,182 ) Amounts recognized in the statement of financial position: Noncurrent liabilities $ (76,314 ) $ (91,182 ) Net amount recognized at end of year $ (76,314 ) $ (91,182 ) Sources of change in regulatory assets (1) : Prior service cost arising during period $ 5,409 $ 1,233 Net loss arising during period 11,757 58,439 Amortization of prior service cost (4,867 ) (4,853 ) Amortization of loss (14,096 ) (9,710 ) Total recognized in regulatory assets (1) $ (1,797 ) $ 45,109 Amounts included in regulatory assets (1) : Net loss $ 209,252 $ 211,592 Prior service cost 25,842 25,299 Total amounts included in regulatory assets $ 235,094 $ 236,891 (1) Represents amounts included in regulatory assets yet to be recognized as components of net prepaid (accrued) benefit costs. Information for Pension Plans with a projected benefit obligation in excess of plan assets Pension benefits 2015 2014 (In Thousands) Benefit obligation $ 723,887 $ 748,421 Plan assets 647,573 657,239 Benefit obligation in excess of plan assets $ 76,314 $ 91,182 IPL’s total benefit obligation in excess of plan assets was $ 76.3 million as of December 31, 2015 ($ 75.3 million Defined Benefit Pension Plan and $1.0 million Supplemental Retirement Plan). Information for Pension Plans with an accumulated benefit obligation in excess of plan assets Pension benefits 2015 2014 (In Thousands) Accumulated benefit obligation $ 712,297 $ 734,328 Plan assets 647,573 657,239 Accumulated benefit obligation in excess of plan assets $ 64,724 $ 77,089 IPL’s total accumulated benefit obligation in excess of plan assets was $64.7 million as of December 31, 2015 ( $63.7 million Defined Benefit Pension Plan and $1.0 million Supplemental Retirement Plan). Pension Benefits and Expense Reported expenses relevant to the Defined Benefit Pension Plan are dependent upon numerous factors resulting from actual plan experience and assumptions of future experience, including the performance of plan assets and actual benefits paid out in future years. Pension costs associated with the Defined Benefit Pension Plan are impacted by the level of contributions made to the plan, earnings on plan assets, the adoption of new mortality tables, and employee demographics, including age, job responsibilities, salary and employment periods. Changes made to the provisions of the Defined Benefit Pension Plan may impact current and future pension costs. Pension costs may also be significantly affected by changes in key actuarial assumptions, including anticipated rates of return on plan assets and the corporate bond discount rates, as well as, the adoption of a new mortality table used in determining the projected benefit obligation and pension costs. Effective January 1, 2016 the Company will apply a disaggregated discount rate approach for determining service cost and interest cost for its defined benefit pension plans and postretirement plans. Refer to Note 1, “ Overview and Summary of Significant Accounting Policies ” for further information relating to this change in estimate. The impact of the change in approach is a reduction in: (1) expected service costs of $0.4 million for pension plans in 2016 ( $0.4 million Defined Benefit Pension Plan and $0.0 million Supplemental Retirement Plan), and (2) expected interest costs of $5.3 million for pension plans in 2016 ( $5.3 million Defined Benefit Pension Plan and $0.0 million Supplemental Retirement Plan). The 2015 net actuarial loss of $11.8 million is comprised of two parts: (1) a $43.8 million pension asset actuarial loss primarily due to lower than expected return on assets; partially offset by (2) a $32.0 million pension liability actuarial gain primarily due to an increase in the discount rate used to value pension liabilities. The unrecognized net loss of $209.3 million in the Pension Plans has accumulated over time primarily due to the long-term declining trend in corporate bond rates, the lower than expected return on assets during the year 2008, and the adoption of new mortality tables which increased the expected benefit obligation due to the longer expected lives of plan participants, since ASC 715 was adopted. During 2015, the accumulated net loss was decreased due to a combination of higher discount rates used to value pension liabilities; as well as, the year 2015 amortization of accumulated loss, which was partially offset by a lower than expected return on pension assets. The unrecognized net loss, to the extent that it exceeds 10% of the greater of the benefit obligation or the assets, will be amortized and included as a component of net periodic benefit cost in future years. The amortization period is approximately 9.77 years based on estimated demographic data as of December 31, 2015 . The projected benefit obligation of $723.9 million , less the fair value of assets of $647.6 million results in an unfunded status of $(76.3) million at December 31, 2015 . Pension benefits for 2015 2014 2013 (In Thousands) Components of net periodic benefit cost: Service cost $ 8,314 $ 7,231 $ 9,195 Interest cost 29,638 31,154 28,363 Expected return on plan assets (1) (44,819 ) (41,893 ) (38,287 ) Amortization of prior service cost 4,867 4,853 4,916 Recognized actuarial loss 13,890 9,710 22,735 Recognized settlement loss 206 — — — Total pension cost 12,096 11,055 26,922 Less: amounts capitalized 1,403 1,426 2,881 Amount charged to expense $ 10,693 $ 9,629 $ 24,041 Rates relevant to each year’s expense calculations: Discount rate – defined benefit pension plan 4.06 % 4.92 % 3.80 % Discount rate – supplemental retirement plan 3.82 % 4.64 % 3.41 % Expected return on defined benefit pension plan assets 6.75 % 7.00 % 7.25 % Expected return on supplemental retirement plan assets 6.75 % 7.00 % 7.25 % (1) For purposes of calculating the expected return on pension plan assets under GAAP, the market-related value of assets (MRVA) is used. GAAP requires that the difference between actual plan asset returns and estimated plan asset returns be amortized into the MRVA equally over a period not to exceed five years. We use a methodology under which we include the difference between actual and estimated asset returns in the MRVA equally over a three year period. The MRVA used in the calculation of expected return on pension plan assets was approximately $643.0 million in 2015, $652.2 million in 2014, and $556.4 million in 2013. Pension expense for the following year is determined as of the December 31 measurement date based on the fair value of the Pension Plans’ assets, the expected long-term rate of return on plan assets, a mortality table assumption that reflects the life expectancy of plan participants, and a discount rate used to determine the projected benefit obligation. In establishing our expected long-term rate of return assumption, we utilize a methodology developed by the plan’s investment consultant who maintains a capital market assumption model that takes into consideration risk, return, and correlation assumptions across asset classes. For 2015, pension expense was determined using an assumed long-term rate of return on plan assets of 6.75% . As of the December 31, 2015 measurement date, IPL increased the discount rate from 4.06% to 4.42% for the Defined Benefit Pension Plan and increased the discount rate from 3.82% to 4.19% for the Supplemental Retirement Plan. The discount rate assumption affects the pension expense determined for 2016. In addition, IPL kept the expected long-term rate of return on plan assets at 6.75% effective January 1, 2016. The expected long-term rate of return assumption affects the pension expense determined for 2016. The effect on 2016 total pension expense of a 25 basis point increase and decrease in the assumed discount rate is $(1.3) million and $1.4 million , respectively. In determining the discount rate to use for valuing liabilities we use the market yield curve on high-quality fixed income investments as of December 31, 2015. We project the expected benefit payments under the plan based on participant data and based on certain assumptions concerning mortality, retirement rates, termination rates, etc. The expected benefit payments for each year are discounted back to the measurement date using the appropriate spot rate for each half-year from the yield curve, thereby obtaining a present value of all expected future benefit payments using the yield curve. Finally, an equivalent single discount rate is determined which produces a present value equal to the present value determined using the full yield curve. Expected amortization The estimated net loss and prior service cost for the Pension Plans that will be amortized from the regulatory asset into net periodic benefit cost over the 2016 plan year are $13.9 million and $5.2 million , respectively (Defined Benefit Pension Plan of $13.7 million and $5.2 million , respectively; and the Supplemental Retirement Plan of $0.2 million and $0.0 million , respectively). Pension Plan Assets and Fair Value Measurements Pension plan assets consist of investments in equities (domestic and international), fixed income securities, and short-term securities. Differences between actual portfolio returns and expected returns may result in increased or decreased pension costs in future periods. Pension costs are determined as of the plan’s measurement date of December 31, 2015. Pension costs are determined for the following year based on the market value of pension plan assets, expected level of employer contributions, a discount rate used to determine the projected benefit obligation and the expected long-term rate of return on plan assets. Fair value is defined under ASC 820 as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., an exit price). The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3) as discussed in Note 1. Purchases and sales of securities are recorded on a trade-date basis. Interest income is recorded as earned. Dividends are recorded on the ex-dividend date. Net appreciation includes the Plan’s gains and losses on investments bought and sold, as well as held, during the year. A description of the valuation methodologies used for each major class of assets and liabilities measured at fair value follows: • Other than common/collective trust funds, hedge funds and non U.S. treasury debt securities, all the Plan’s investments have quoted market prices and are categorized as Level 1 in the fair value hierarchy. • The Plan’s hedge fund investment is valued at net asset value of units held by the Plan. Unit value is determined primarily by references to the fund’s underlying assets, which are principally investments in another hedge fund which invests in U.S. and international equities. The Plan may redeem its ownership interest in the hedge fund at net asset value, with 60 days’ notice, on quarterly terms. • The Plan’s investments in common/collective trust funds are valued at the net asset value of the units of the common/collective trust funds held by the Plan at year-end. The Plan may redeem its units of the common/collective trust funds at net asset value daily. The objective of the common/collective trust funds the Plan is invested in is to track the performance of the Russell 1000 Growth or Russell 1000 Value index. These net asset values have been determined based on the market value of the underlying equity securities held by the common/collective trust funds. • The Plan’s investments in corporate bonds, municipal bonds, and U.S. Government agency fixed income securities are valued from third-party pricing sources, but they generally do not represent transaction prices for the identical security in an active market nor does it represent data obtained from an exchange. • The Plan’s investments in hedge funds, common/collective trust funds, and non U.S. treasury debt securities have been recorded at fair value and are all categorized as Level 2 investments in the fair value hierarchy. The primary objective of the Plan is to provide a source of retirement income for its participants and beneficiaries, while the primary financial objective is to improve the unfunded status of the Plan. A secondary financial objective is, where possible, to minimize pension expense volatility. The objective is based on a long-term investment horizon, so that interim fluctuations should be viewed with appropriate perspective. There can be no assurance that these objectives will be met. In establishing our expected long-term rate of return assumption, we utilize a methodology developed by the plan’s investment consultant who maintains a capital market assumption model that takes into consideration risk, return and correlation assumptions across asset classes. A combination of quantitative analysis of historical data and qualitative judgment is used to capture trends, structural changes and potential scenarios not reflected in historical data. The result of the analyses is a series of inputs that produce a picture of how the plan consultant believes portfolios are likely to behave through time. Capital market assumptions are intended to reflect the behavior of asset classes observed over several market cycles. Stress assumptions are also examined, since the characteristics of asset classes are constantly changing. A dynamic model is employed to manage the numerous assumptions required to estimate portfolio characteristics under different base currencies, time horizons and inflation expectations. The Plan consultant develops forward-looking, long-term capital market assumptions for risk, return and correlations for a variety of global asset classes, interest rates and inflation. These assumptions are created using a combination of historical analysis, current market environment assessment and by applying the consultant’s own judgment. The consultant then determines an equilibrium long-term rate of return. We then take into consideration the investment manager/consultant expenses, as well as any other expenses expected to be paid out of the Plan’s trust. Finally, we have the plan’s actuary perform a tolerance test of the consultant’s equilibrium expected long-term rate of return. We use an expected long-term rate of return compatible with the actuary’s tolerance level. The following table summarizes the Company’s target pension plan allocation for 2015 : Asset Category: Target Allocations Equity Securities 60% Debt Securities 40% Fair Value Measurements at December 31, 2015 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 176 $ 176 $ — — % Mutual funds: U.S. equities 318,368 318,368 — 49 % International equities 60,751 60,751 — 10 % Fixed income 215,325 215,325 — 33 % Fixed income securities: U.S. Treasury securities 52,953 52,953 — 8 % Total $ 647,573 $ 647,573 $ — 100 % Fair Value Measurements at December 31, 2014 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 2,575 $ 2,575 $ — — % Mutual funds: U.S. equities 325,370 325,370 — 50 % International equities 56,662 56,662 — 9 % Fixed income 205,409 205,409 — 31 % Fixed income securities: U.S. Treasury securities 66,913 66,913 — 10 % Hedge funds 310 — 310 — % Total $ 657,239 $ 656,929 $ 310 100 % Pension Funding We contributed $25.2 million , $54.1 million , and $49.7 million to the Pension Plans in 2015 , 2014 and 2013 , respectively. Funding for the qualified Defined Benefit Pension Plan is based upon actuarially determined contributions that take into account the amount deductible for income tax purposes and the minimum contribution required under ERISA, as amended by the Pension Protection Act of 2006, as well as targeted funding levels necessary to meet certain thresholds. From an ERISA funding perspective, IPL’s funded target liability percentage was estimated to be 112%. In addition to the surplus, IPL must also contribute the normal service cost earned by active participants during the plan year. The funding of normal cost is expected to be about $7.1 million in 2016 , which includes $2.3 million for plan expenses. Each year thereafter, if the plan’s underfunding increases to more than the present value of the remaining annual installments, the excess is separately amortized over a seven-year period. IPL elected to fund $15.9 million in January 2016, which satisfies all funding requirements for the calendar year 2016. IPL’s funding policy for the Pension Plans is to contribute annually no less than the minimum required by applicable law, and no more than the maximum amount that can be deducted for federal income tax purposes. Benefit payments made from the Pension Plans for the years ended December 31, 2015 and 2014 were $35.7 million and $32.6 million , respectively. Expected benefit payments are expected to be paid out of the Pension Plans as follows: Year Pension Benefits (In Thousands) 2016 $ 38,289 2017 39,909 2018 41,213 2019 42,638 2020 43,920 2021 through 2025 233,449
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Benefit Plans	BENEFIT PLANS Defined Contribution Plans All of IPL’s employees are covered by one of two defined contribution plans, the Thrift Plan or the RSP: The Thrift Plan Approximately 84% of IPL’s active employees are covered by the Thrift Plan, a qualified defined contribution plan. All union new hires are covered under the Thrift Plan. Participants elect to make contributions to the Thrift Plan based on a percentage of their base compensation. Each participant’s contribution is matched up to certain thresholds of base compensation. The IBEW clerical-technical union new hires receive an annual lump sum company contribution into the Thrift Plan in addition to the company match. Employer contributions to the Thrift Plan were $3.1 million , $3.0 million and $3.0 million for 2015 , 2014 and 2013 , respectively. The RSP Approximately 16% of IPL’s active employees are covered by the RSP, a qualified defined contribution plan containing a profit sharing component. All non-union new hires are covered under the RSP. Participants elect to make contributions to the RSP based on a percentage of their taxable compensation. Each participant’s contribution is matched in amounts up to, but not exceeding, 5% of the participant’s taxable compensation. In addition, the RSP has a profit sharing component whereby IPL contributes a percentage of each employee’s annual salary into the plan on a pre-tax basis. The profit sharing percentage is determined by the AES board of directors on an annual basis. Employer payroll-matching and profit sharing contributions (by IPL) relating to the RSP were $0.3 million , $1.5 million and $1.8 million for 2015 , 2014 and 2013 , respectively. The decrease in the 2015 net contributions is a result of truing up prior year estimated profit sharing contributions. Defined Benefit Plans Approximately 77% of IPL’s active employees are covered by the qualified Defined Benefit Pension Plan; while approximately 7% of active employees are IBEW clerical-technical unit employees who are only eligible for the Thrift Plan, which is a defined contribution plan. The remaining 16% of active employees are covered by the RSP. The RSP is a qualified defined contribution plan containing a profit sharing component. All non-union new hires are covered under the RSP, while IBEW physical unit union new hires are covered under the Defined Benefit Pension Plan and Thrift Plan. The IBEW clerical-technical unit new hires are no longer covered under the Defined Benefit Pension Plan but do receive an annual lump sum company contribution into the Thrift Plan, in addition to the company match. The Defined Benefit Pension Plan is noncontributory and is funded by IPL through a trust. Effective April 1, 2015, benefits for non-union participants in the Defined Benefit Pension Plan are based on salary and years of service. Benefits for eligible union participants are based on each individual employee's pension band and years of service as opposed to their compensation. Pension bands are based primarily on job duties and responsibilities. Additionally, a small group of former officers and their surviving spouses are covered under a funded non-qualified Supplemental Retirement Plan. The total number of participants in the plan as of December 31, 2015 was 24 . The plan is closed to new participants. IPL also provides postretirement health care benefits to certain active or retired employees and the spouses of certain active or retired employees. Approximately 171 active employees and 27 retirees (including spouses) were receiving such benefits or entitled to future benefits as of January 1, 2015. The plan is unfunded. These postretirement health care benefits and the related obligation were not material to the consolidated financial statements in the periods covered by this report. The following table presents information relating to the Pension Plans: Pension benefits 2015 2014 (In Thousands) Change in benefit obligation: Projected benefit obligation at January 1 $ 748,421 $ 650,713 Service cost 8,314 7,231 Interest cost 29,638 31,154 Actuarial (gain) loss (31,989 ) 90,693 Amendments (primarily increases in pension bands) 5,409 1,233 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Projected benefit obligation at December 31 723,887 748,421 Change in plan assets: Fair value of plan assets at January 1 657,239 561,586 Actual return on plan assets 1,074 74,147 Employer contributions 25,166 54,109 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Fair value of plan assets at December 31 647,573 657,239 Unfunded status $ (76,314 ) $ (91,182 ) Amounts recognized in the statement of financial position: Noncurrent liabilities $ (76,314 ) $ (91,182 ) Net amount recognized at end of year $ (76,314 ) $ (91,182 ) Sources of change in regulatory assets (1) : Prior service cost arising during period $ 5,409 $ 1,233 Net loss arising during period 11,757 58,439 Amortization of prior service cost (4,867 ) (4,853 ) Amortization of loss (14,096 ) (9,710 ) Total recognized in regulatory assets (1) $ (1,797 ) $ 45,109 Amounts included in regulatory assets (1) : Net loss $ 209,252 $ 211,592 Prior service cost 25,842 25,299 Total amounts included in regulatory assets $ 235,094 $ 236,891 (1) Represents amounts included in regulatory assets yet to be recognized as components of net prepaid (accrued) benefit costs. Information for Pension Plans with a projected benefit obligation in excess of plan assets Pension benefits 2015 2014 (In Thousands) Benefit obligation $ 723,887 $ 748,421 Plan assets 647,573 657,239 Benefit obligation in excess of plan assets $ 76,314 $ 91,182 IPL’s total benefit obligation in excess of plan assets was $76.3 million as of December 31, 2015 ( $75.3 million Defined Benefit Pension Plan and $1.0 million Supplemental Retirement Plan). Information for Pension Plans with an accumulated benefit obligation in excess of plan assets Pension benefits 2015 2014 (In Thousands) Accumulated benefit obligation $ 712,297 $ 734,328 Plan assets 647,573 657,239 Accumulated benefit obligation in excess of plan assets $ 64,724 $ 77,089 IPL’s total accumulated benefit obligation in excess of plan assets was $64.7 million as of December 31, 2015 ( $63.7 million Defined Benefit Pension Plan and $1.0 million Supplemental Retirement Plan). Pension Benefits and Expense Reported expenses relevant to the Defined Benefit Pension Plan are dependent upon numerous factors resulting from actual plan experience and assumptions of future experience, including the performance of plan assets and actual benefits paid out in future years. Pension costs associated with the Defined Benefit Pension Plan are impacted by the level of contributions made to the plan, earnings on plan assets, the adoption of new mortality tables, and employee demographics, including age, job responsibilities, salary and employment periods. Changes made to the provisions of the Defined Benefit Pension Plan may impact current and future pension costs. Pension costs may also be significantly affected by changes in key actuarial assumptions, including anticipated rates of return on plan assets and the corporate bond discount rates, as well as, the adoption of a new mortality table used in determining the projected benefit obligation and pension costs. Effective January 1, 2016 the Company will apply a disaggregated discount rate approach for determining service cost and interest cost for its defined benefit pension plans and postretirement plans. Refer to Note 1, “ Overview and Summary of Significant Accounting Policies ” for further information relating to this change in estimate. The impact of the change in approach is a reduction in: (1) expected service costs of $0.4 million for pension plans in 2016 ( $0.4 million Defined Benefit Pension Plan and $0.0 million Supplemental Retirement Plan), and (2) expected interest costs of $5.3 million for pension plans in 2016 ( $5.3 million Defined Benefit Pension Plan and $0.0 million Supplemental Retirement Plan). The 2015 net actuarial loss of $11.8 million is comprised of two parts: (1) a $43.8 million pension asset actuarial loss primarily due to lower than expected return on assets; partially offset by (2) a $32 million pension liability actuarial gain primarily due to an increase in the discount rate used to value pension liabilities. The unrecognized net loss of $209.3 million in the Pension Plans has accumulated over time primarily due to the long-term declining trend in corporate bond rates, the lower than expected return on assets during the year 2008, and the adoption of new mortality tables which increased the expected benefit obligation due to the longer expected lives of plan participants, since ASC 715 was adopted. During 2015, the accumulated net loss was decreased due to a combination of higher discount rates used to value pension liabilities; as well as, the year 2015 amortization of accumulated loss, which was partially offset by a lower than expected return on pension assets. The unrecognized net loss, to the extent that it exceeds 10% of the greater of the benefit obligation or the assets, will be amortized and included as a component of net periodic benefit cost in future years. The amortization period is approximately 9.77 years based on estimated demographic data as of December 31, 2015 . The projected benefit obligation of $723.9 million , less the fair value of assets of $647.6 million results in an unfunded status of $(76.3) million at December 31, 2015 . Pension benefits for 2015 2014 2013 (In Thousands) Components of net periodic benefit cost: Service cost $ 8,314 $ 7,231 $ 9,195 Interest cost 29,638 31,154 28,363 Expected return on plan assets (1) (44,819 ) (41,893 ) (38,287 ) Amortization of prior service cost 4,867 4,853 4,916 Recognized actuarial loss 13,890 9,710 22,735 Recognized settlement loss 206 — — Total pension cost 12,096 11,055 26,922 Less: amounts capitalized 1,403 1,426 2,881 Amount charged to expense $ 10,693 $ 9,629 $ 24,041 Rates relevant to each year’s expense calculations: Discount rate – defined benefit pension plan 4.06 % 4.92 % 3.80 % Discount rate – supplemental retirement plan 3.82 % 4.64 % 3.41 % Expected return on defined benefit pension plan assets 6.75 % 7.00 % 7.25 % Expected return on supplemental retirement plan assets 6.75 % 7.00 % 7.25 % (1) For purposes of calculating the expected return on pension plan assets under GAAP, the market-related value of assets (MRVA) is used. GAAP requires that the difference between actual plan asset returns and estimated plan asset returns be amortized into the MRVA equally over a period not to exceed five years. We use a methodology under which we include the difference between actual and estimated asset returns in the MRVA equally over a three year period. The MRVA used in the calculation of expected return on pension plan assets was approximately $643.0 million in 2015, $652.2 million in 2014, and $556.4 million in 2013. Pension expense for the following year is determined as of the December 31 measurement date based on the fair value of the Pension Plans’ assets, the expected long-term rate of return on plan assets, a mortality table assumption that reflects the life expectancy of plan participants, and a discount rate used to determine the projected benefit obligation. In establishing our expected long-term rate of return assumption, we utilize a methodology developed by the plan’s investment consultant who maintains a capital market assumption model that takes into consideration risk, return, and correlation assumptions across asset classes. For 2015 , pension expense was determined using an assumed long-term rate of return on plan assets of 6.75% . As of the December 31, 2015 measurement date, IPL increased the discount rate from 4.06% to 4.42% for the Defined Benefit Pension Plan and increased the discount rate from 3.82% to 4.19% for the Supplemental Retirement Plan. The discount rate assumption affects the pension expense determined for 2016. In addition, IPL kept the expected long-term rate of return on plan assets at 6.75% effective January 1, 2016. The expected long-term rate of return assumption affects the pension expense determined for 2016 . The effect on 2016 total pension expense of a 25 basis point increase and decrease in the assumed discount rate is $(1.3) million and $1.4 million , respectively. In determining the discount rate to use for valuing liabilities we use the market yield curve on high-quality fixed income investments as of December 31, 2015. We project the expected benefit payments under the plan based on participant data and based on certain assumptions concerning mortality, retirement rates, termination rates, etc. The expected benefit payments for each year are discounted back to the measurement date using the appropriate spot rate for each half-year from the yield curve, thereby obtaining a present value of all expected future benefit payments using the yield curve. Finally, an equivalent single discount rate is determined which produces a present value equal to the present value determined using the full yield curve. Expected amortization The estimated net loss and prior service cost for the Pension Plans that will be amortized from the regulatory asset into net periodic benefit cost over the 2016 plan year are $13.9 million and $5.2 million , respectively (Defined Benefit Pension Plan of $13.7 million and $5.2 million , respectively; and the Supplemental Retirement Plan of $0.2 million and $0.0 million , respectively). Pension Plan Assets and Fair Value Measurements Pension plan assets consist of investments in equities (domestic and international), fixed income securities, and short-term securities. Differences between actual portfolio returns and expected returns may result in increased or decreased pension costs in future periods. Pension costs are determined as of the plan’s measurement date of December 31, 2015. Pension costs are determined for the following year based on the market value of pension plan assets, expected level of employer contributions, a discount rate used to determine the projected benefit obligation and the expected long-term rate of return on plan assets. Fair value is defined under ASC 820 as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., an exit price). The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3) as discussed in Note 1. Purchases and sales of securities are recorded on a trade-date basis. Interest income is recorded as earned. Dividends are recorded on the ex-dividend date. Net appreciation includes the Plan’s gains and losses on investments bought and sold, as well as held, during the year. A description of the valuation methodologies used for each major class of assets and liabilities measured at fair value follows: • Other than common/collective trust funds, hedge funds and non U.S. treasury debt securities, all the Plan’s investments have quoted market prices and are categorized as Level 1 in the fair value hierarchy. • The Plan’s hedge fund investment is valued at net asset value of units held by the Plan. Unit value is determined primarily by references to the fund’s underlying assets, which are principally investments in another hedge fund which invests in U.S. and international equities. The Plan may redeem its ownership interest in the hedge fund at net asset value, with 60 days’ notice, on quarterly terms. • The Plan’s investments in common/collective trust funds are valued at the net asset value of the units of the common/collective trust funds held by the Plan at year-end. The Plan may redeem its units of the common/collective trust funds at net asset value daily. The objective of the common/collective trust funds the Plan is invested in is to track the performance of the Russell 1000 Growth or Russell 1000 Value index. These net asset values have been determined based on the market value of the underlying equity securities held by the common/collective trust funds. • The Plan’s investments in corporate bonds, municipal bonds, and U.S. Government agency fixed income securities are valued from third-party pricing sources, but they generally do not represent transaction prices for the identical security in an active market nor does it represent data obtained from an exchange. • The Plan’s investments in hedge funds, common/collective trust funds, and non U.S. treasury debt securities have been recorded at fair value and are all categorized as Level 2 investments in the fair value hierarchy. The primary objective of the Plan is to provide a source of retirement income for its participants and beneficiaries, while the primary financial objective is to improve the unfunded status of the Plan. A secondary financial objective is, where possible, to minimize pension expense volatility. The objective is based on a long-term investment horizon, so that interim fluctuations should be viewed with appropriate perspective. There can be no assurance that these objectives will be met. In establishing our expected long-term rate of return assumption, we utilize a methodology developed by the plan’s investment consultant who maintains a capital market assumption model that takes into consideration risk, return and correlation assumptions across asset classes. A combination of quantitative analysis of historical data and qualitative judgment is used to capture trends, structural changes and potential scenarios not reflected in historical data. The result of the analyses is a series of inputs that produce a picture of how the plan consultant believes portfolios are likely to behave through time. Capital market assumptions are intended to reflect the behavior of asset classes observed over several market cycles. Stress assumptions are also examined, since the characteristics of asset classes are constantly changing. A dynamic model is employed to manage the numerous assumptions required to estimate portfolio characteristics under different base currencies, time horizons and inflation expectations. The Plan consultant develops forward-looking, long-term capital market assumptions for risk, return and correlations for a variety of global asset classes, interest rates and inflation. These assumptions are created using a combination of historical analysis, current market environment assessment and by applying the consultant’s own judgment. The consultant then determines an equilibrium long-term rate of return. We then take into consideration the investment manager/consultant expenses, as well as any other expenses expected to be paid out of the Plan’s trust. Finally, we have the plan’s actuary perform a tolerance test of the consultant’s equilibrium expected long-term rate of return. We use an expected long-term rate of return compatible with the actuary’s tolerance level. The following table summarizes the Company’s target pension plan allocation for 2015 : Asset Category: Target Allocations Equity Securities 60% Debt Securities 40% Fair Value Measurements at December 31, 2015 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 176 $ 176 $ — — % Mutual funds: U.S. equities 318,368 318,368 — 49 % International equities 60,751 60,751 — 10 % Fixed income 215,325 215,325 — 33 % Fixed income securities: U.S. Treasury securities 52,953 52,953 — 8 % Total $ 647,573 $ 647,573 $ — 100 % Fair Value Measurements at December 31, 2014 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 2,575 $ 2,575 $ — — % Mutual funds: U.S. equities 325,370 325,370 — 50 % International equities 56,662 56,662 — 9 % Fixed income 205,409 205,409 — 31 % Fixed income securities: U.S. Treasury securities 66,913 66,913 — 10 % Hedge funds 310 — 310 — % Total $ 657,239 $ 656,929 $ 310 100 % Pension Funding We contributed $25.2 million , $54.1 million , and $49.7 million to the Pension Plans in 2015 , 2014 and 2013 , respectively. Funding for the qualified Defined Benefit Pension Plan is based upon actuarially determined contributions that take into account the amount deductible for income tax purposes and the minimum contribution required under ERISA, as amended by the Pension Protection Act of 2006, as well as targeted funding levels necessary to meet certain thresholds. From an ERISA funding perspective, IPL’s funded target liability percentage was estimated to be 112% . In addition to the surplus, IPL must also contribute the normal service cost earned by active participants during the plan year. The funding of normal cost is expected to be about $7.1 million in 2016 , which includes $2.3 million for plan expenses. Each year thereafter, if the plan’s underfunding increases to more than the present value of the remaining annual installments, the excess is separately amortized over a seven-year period. IPL elected to fund $15.9 million in January 2016, which satisfies all funding requirements for the calendar year 2016. IPL’s funding policy for the Pension Plans is to contribute annually no less than the minimum required by applicable law, and no more than the maximum amount that can be deducted for federal income tax purposes. Benefit payments made from the Pension Plans for the years ended December 31, 2015 and 2014 were $35.7 million and $32.6 million , respectively. Expected benefit payments are expected to be paid out of the Pension Plans as follows: Year Pension Benefits (In Thousands) 2016 $ 38,289 2017 39,909 2018 41,213 2019 42,638 2020 43,920 2021 through 2025 233,449

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Legal Loss Contingencies IPALCO and IPL are involved in litigation arising in the normal course of business. While the results of such litigation cannot be predicted with certainty, management believes that the final outcome will not have a material adverse effect on IPALCO’s results of operations, financial condition and cash flows. Amounts accrued or expensed for legal or environmental contingencies collectively during the periods covered by this report have not been material to IPALCO’s audited Consolidated Financial Statements. Environmental Loss Contingencies We are subject to various federal, state, regional and local environmental protection and health and safety laws and regulations governing, among other things, the generation, storage, handling, use, disposal and transportation of hazardous materials; the emission and discharge of hazardous and other materials into the environment; and the health and safety of our employees. These laws and regulations often require a lengthy and complex process of obtaining and renewing permits and other governmental authorizations from federal, state and local agencies. Violation of these laws, regulations or permits can result in substantial fines, other sanctions, permit revocation and/or facility shutdowns. We cannot assure that we have been or will be at all times in full compliance with such laws, regulations and permits. New Source Review In October 2009, IPL received a NOV and Finding of Violation from the EPA pursuant to the Federal Clean Air Act Section 113(a). The NOV alleges violations of the Federal Clean Air Act at IPL’s three primarily coal-fired electric generating facilities dating back to 1986. The alleged violations primarily pertain to the PSD and nonattainment New Source Review requirements under the Federal Clean Air Act. Since receiving the letter, IPL management has met with the EPA staff regarding possible resolutions of the NOV. At this time, we cannot predict the ultimate resolution of this matter. However, settlements and litigated outcomes of similar cases have required companies to pay civil penalties, install additional pollution control technology on coal-fired electric generating units, retire existing generating units, and invest in additional environmental projects. A similar outcome in this case could have a material impact on our business. We would seek recovery of any operating or capital expenditures, but not fines or penalties, related to air pollution control technology to reduce regulated air emissions; however, there can be no assurances that we would be successful in this regard. IPL has recorded a contingent liability related to this matter.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Legal Loss Contingencies IPL is involved in litigation arising in the normal course of business. While the results of such litigation cannot be predicted with certainty, management believes that the final outcome will not have a material adverse effect on IPL’s results of operations, financial condition and cash flows. Amounts accrued or expensed for legal or environmental contingencies collectively during the periods covered by this report have not been material to IPL’s audited Consolidated Financial Statements. Environmental Loss Contingencies We are subject to various federal, state, regional and local environmental protection and health and safety laws and regulations governing, among other things, the generation, storage, handling, use, disposal and transportation of hazardous materials; the emission and discharge of hazardous and other materials into the environment; and the health and safety of our employees. These laws and regulations often require a lengthy and complex process of obtaining and renewing permits and other governmental authorizations from federal, state and local agencies. Violation of these laws, regulations or permits can result in substantial fines, other sanctions, permit revocation and/or facility shutdowns. We cannot assure that we have been or will be at all times in full compliance with such laws, regulations and permits. New Source Review In October 2009, IPL received a NOV and Finding of Violation from the EPA pursuant to the Federal Clean Air Act Section 113(a). The NOV alleges violations of the Federal Clean Air Act at IPL’s three primarily coal-fired electric generating facilities dating back to 1986. The alleged violations primarily pertain to the PSD and nonattainment New Source Review requirements under the Federal Clean Air Act. Since receiving the letter, IPL management has met with the EPA staff regarding possible resolutions of the NOV. At this time, we cannot predict the ultimate resolution of this matter. However, settlements and litigated outcomes of similar cases have required companies to pay civil penalties, install additional pollution control technology on coal-fired electric generating units, retire existing generating units, and invest in additional environmental projects. A similar outcome in this case could have a material impact on our business. We would seek recovery of any operating or capital expenditures, but not fines or penalties, related to air pollution control technology to reduce regulated air emissions; however, there can be no assurances that we would be successful in this regard. IPL has recorded a contingent liability related to this matter.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Related Party Transactions	RELATED PARTY TRANSACTIONS IPL participates in a property insurance program in which IPL buys insurance from AES Global Insurance Company, a wholly‑owned subsidiary of AES. IPL is not self-insured on property insurance with the exception of a $5 million self-insured retention per occurrence. Except for IPL’s large substations, IPL does not carry insurance on transmission and distribution assets, which are considered to be outside the scope of property insurance. AES and other AES subsidiaries, including IPALCO, also participate in the AES global insurance program. IPL pays premiums for a policy that is written and administered by a third-party insurance company. The premiums paid to this third-party administrator by the participants are deposited into a trust fund owned by AES Global Insurance Company, but controlled by the third-party administrator. The cost to IPL of coverage under this program was approximately $2.7 million , $3.2 million , and $3.1 million in 2015 , 2014 and 2013 , respectively, and is recorded in “ Other operating expenses” on the accompanying Consolidated Statements of Income. As of December 31, 2015 and 2014 , we had prepaid approximately $2.2 million and $3.1 million , respectively, which is recorded in “ Prepayments and other current assets” on the accompanying Consolidated Balance Sheets. IPL participates in an agreement with Health and Welfare Benefit Plans LLC, an affiliate of AES, to participate in a group benefits program, including but not limited to, health, dental, vision and life benefits. Health and Welfare Benefit Plans LLC administers the financial aspects of the group insurance program, receives all premium payments from the participating affiliates, and makes all vendor payments. The cost of coverage under this program was approximately $24.5 million , $20.1 million , and $22.3 million in 2015 , 2014 and 2013 , respectively, and is recorded in “ Other operating expenses” on the accompanying Consolidated Statements of Income. As of December 31, 2015 and 2014 we had prepaid approximately $0 million and $0.1 million for coverage under this plan, which is recorded in “ Prepayments and other current assets” on the accompanying Consolidated Balance Sheets. AES files federal and state income tax returns which consolidate IPALCO and its subsidiaries. Under a tax sharing agreement with AES, IPALCO is responsible for the income taxes associated with its own taxable income and records the provision for income taxes using a separate return method. IPALCO had a receivable balance under this agreement of $0.7 million as of December 31, 2015 and 2014 , respectively, which is recorded in “ Prepayments and other current assets” on the accompanying Consolidated Balance Sheets. Long-term Compensation Plan During 2015 , 2014 and 2013 , many of IPL’s non-union employees received benefits under the AES Long-term Compensation Plan, a deferred compensation program. This type of plan is a common employee retention tool used in our industry. Benefits under this plan are granted in the form of performance units payable in cash and AES restricted stock units and options to purchase shares of AES common stock. All such components vest over a three -year period and the terms of the AES restricted stock unit issued prior to 2011 also include a two year minimum holding period after the awards vest. Awards made in 2011 and for subsequent years will not be subject to a two year holding period. In addition, the performance units payable in cash are subject to certain AES performance criteria. Total deferred compensation expense recorded during 2015 , 2014 and 2013 was $0.7 million , $0.7 million and $1.1 million , respectively, and was included in “ Other Operating Expenses” on IPALCO’s Consolidated Statements of Income. The value of these benefits is being recognized over the 36 month vesting period and a portion is recorded as miscellaneous deferred credits with the remainder recorded as “ Paid in capital” on IPALCO’s Consolidated Balance Sheets in accordance with ASC 718 “Compensation – Stock Compensation.” See also Note 9, “ Benefit Plans” to the audited Consolidated Financial Statements of IPALCO for a description of benefits awarded to IPL employees by AES under the RSP. Service Company Effective January 1, 2014, the Service Company began providing services including operations, accounting, legal, human resources, information technology and other corporate services on behalf of companies that are part of the U.S. SBU, including among other companies, IPALCO and IPL. The Service Company allocates the costs for these services based on cost drivers designed to result in fair and equitable allocations. This includes ensuring that the regulated utilities served, including IPL, are not subsidizing costs incurred for the benefit of non-regulated businesses. Total costs incurred by the Service Company on behalf of IPALCO were $23.2 million and $22.0 million during 2015 and 2014, respectively. Total costs incurred by IPALCO on behalf of the Service Company during 2015 and 2014 were $7.5 million and $5.6 million , respectively. IPALCO had a prepaid balance with the Service Company of $1.2 million and $0.4 million as of December 31, 2015 and 2014, respectively. CDPQ Please refer to Note 6, “ Equity – Equity Transactions” for further details. Other In 2014, IPL engaged a third party vendor as part of its replacement generation construction projects. A member of the AES Board of Directors is also currently a member of the Supervisory Board of this vendor. IPL had billings from this vendor of $232.0 million and $80.3 million during 2015 and 2014, respectively. IPL had a payable balance to this vendor of $34.0 million and $11.9 million as of December 31, 2015 and 2014, respectively.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Related Party Transactions	RELATED PARTY TRANSACTIONS IPL participates in a property insurance program in which IPL buys insurance from AES Global Insurance Company, a wholly‑owned subsidiary of AES. IPL is not self-insured on property insurance with the exception of a $5 million self-insured retention per occurrence. Except for IPL’s large substations, IPL does not carry insurance on transmission and distribution assets, which are considered to be outside the scope of property insurance. AES and other AES subsidiaries, including IPL, also participate in the AES global insurance program. IPL pays premiums for a policy that is written and administered by a third-party insurance company. The premiums paid to this third-party administrator by the participants are deposited into a trust fund owned by AES Global Insurance Company, but controlled by the third-party administrator. The cost to IPL of coverage under this program was approximately $2.7 million , $3.2 million , and $3.1 million in 2015 , 2014 and 2013 , respectively, and is recorded in “ Other operating expenses” on the accompanying Consolidated Statements of Income. As of December 31, 2015 and 2014 , we had prepaid approximately $2.2 million and $3.1 million , respectively, which is recorded in “ Prepayments and other current assets” on the accompanying Consolidated Balance Sheets. IPL participates in an agreement with Health and Welfare Benefit Plans LLC, an affiliate of AES, to participate in a group benefits program, including but not limited to, health, dental, vision and life benefits. Health and Welfare Benefit Plans LLC administers the financial aspects of the group insurance program, receives all premium payments from the participating affiliates, and makes all vendor payments. The cost of coverage under this program was approximately $24.5 million , $20.1 million , and $22.3 million in 2015 , 2014 and 2013 , respectively, and is recorded in “ Other operating expenses” on the accompanying Consolidated Statements of Income. As of December 31, 2015 and 2014 we had prepaid approximately $0 million and $0.1 million for coverage under this plan, which is recorded in “ Prepayments and other current assets” on the accompanying Consolidated Balance Sheets. AES files federal and state income tax returns which consolidate IPALCO and its subsidiaries, including IPL. Under a tax sharing agreement with IPALCO, IPL is responsible for the income taxes associated with its own taxable income and records the provision for income taxes using a separate return method. IPL had a receivable balance under this agreement of $2.8 million and $0.3 million as of December 31, 2015 and 2014 , respectively, which is recorded in “ Prepayments and other current assets” on the accompanying Consolidated Balance Sheets. Long-term Compensation Plan During 2015 , 2014 and 2013, many of IPL’s non-union employees received benefits under the AES Long-term Compensation Plan, a deferred compensation program. This type of plan is a common employee retention tool used in our industry. Benefits under this plan are granted in the form of performance units payable in cash and AES restricted stock units and options to purchase shares of AES common stock. All such components vest over a three -year period and the terms of the AES restricted stock unit issued prior to 2011 also include a two year minimum holding period after the awards vest. Awards made in 2011 and for subsequent years will not be subject to a two year holding period. In addition, the performance units payable in cash are subject to certain AES performance criteria. Total deferred compensation expense recorded during 2015 , 2014 and 2013 was $0.7 million , $0.7 million and $1.1 million , respectively, and was included in “ Other Operating Expenses” on IPL’s Consolidated Statements of Income. The value of these benefits is being recognized over the 36 month vesting period and a portion is recorded as miscellaneous deferred credits with the remainder recorded as “ Paid in capital” on IPL’s Consolidated Balance Sheets in accordance with ASC 718 “Compensation – Stock Compensation.” See also Note 9, “Benefit Plans” to the audited Consolidated Financial Statements of IPL for a description of benefits awarded to IPL employees by AES under the RSP. Service Company Effective January 1, 2014, the Service Company began providing services including operations, accounting, legal, human resources, information technology and other corporate services on behalf of companies that are part of the U.S. SBU, including among other companies, IPL. The Service Company allocates the costs for these services based on cost drivers designed to result in fair and equitable allocations. This includes ensuring that the regulated utilities served, including IPL, are not subsidizing costs incurred for the benefit of non-regulated businesses. Total costs incurred by the Service Company on behalf of IPL were $22.6 million and $22.0 million during 2015 and 2014, respectively. Total costs incurred by IPL on behalf of the Service Company during 2015 and 2014 were $7.5 million and $5.6 million , respectively. IPL had a prepaid balance with the Service Company of $1.2 million and $0.4 million as of December 31, 2015 and 2014, respectively. Other In 2014, IPL engaged a third party vendor as part of its replacement generation construction projects. A member of the AES Board of Directors is also currently a member of the Supervisory Board of this vendor. IPL had billings from this vendor of $232.0 million and $80.3 million during 2015 and 2014, respectively. IPL had a payable balance to this vendor of $34.0 million and $11.9 million as of December 31, 2015 and 2014, respectively.

Business Segment Information

Business Segment Information	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Business Segment Information	BUSINESS SEGMENT INFORMATION Operating segments are components of an enterprise that engage in business activities from which it may earn revenues and incur expenses, for which separate financial information is available, and is evaluated regularly by the chief operating decision maker in assessing performance and deciding how to allocate resources. Substantially all of our business consists of the generation, transmission, distribution and sale of electric energy conducted through IPL which is a vertically integrated electric utility. IPALCO’s reportable business segment is its utility segment, with all other non-utility business activities aggregated separately. The non-utility category primarily includes the 2018 IPALCO Notes and the 2020 IPALCO Notes; approximately $1.7 million and $5.9 million of cash and cash equivalents, as of December 31, 2015 and 2014 , respectively; long-term investments of $5.2 million and $5.1 million at December 31, 2015 and 2014 , respectively; and income taxes and interest related to those items. All other assets represented less than 1% of IPALCO’s total assets as of December 31, 2015 and 2014 . The accounting policies of the identified segment are consistent with those policies and procedures described in the summary of significant accounting policies. Intersegment sales, if any, are generally based on prices that reflect the current market conditions. The following table provides information about IPALCO’s business segments (in millions): 2015 2014 2013 Utility All Other Total Utility All Other Total Utility All Other Total Operating revenues $ 1,250 — $ 1,250 $ 1,322 — $ 1,322 $ 1,256 — $ 1,256 Depreciation and amortization 188 — 188 185 — 185 182 — 182 Income taxes 56 (25 ) 32 69 (21 ) 48 58 (20 ) 38 Net income 102 (42 ) 60 110 (32 ) 78 97 (33 ) 64 Utility plant - net of depreciation 3,451 — 3,451 2,857 — 2,857 2,553 — 2,553 Capital expenditures 686 — 686 382 — 382 242 — 242 \
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Business Segment Information	BUSINESS SEGMENT INFORMATION Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the chief operating decision maker in assessing performance and deciding how to allocate resources. All of IPL’s current business consists of the generation, transmission, distribution and sale of electric energy, and therefore IPL had only one reportable segment.

Retrospective Adoption of ASU 2

Retrospective Adoption of ASU 2015-03	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Retrospective Adoption of ASU 2015-03	RETROSPECTIVE ADOPTION OF ASU 2015-03 As discussed in Note 1, “ Overview and Summary of Significant Accounting Policies ,” ASU 2015-03 simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. As a result of the retrospective adoption of ASU 2015-03 effective January 1, 2016, deferred financing costs of approximately $20.8 million and $15.3 million previously classified within Deferred Debits were reclassified to reduce the related debt liabilities as of December 31, 2015 and 2014, respectively. Accordingly, the accompanying Consolidated Balance Sheets, Unconsolidated Balance Sheets (included in Schedule I) and Note 4 to the Condensed Financial Information of Registrant (included in Schedule I) have been updated. However, Note 7, “ Debt ,” remains unchanged from what was previously disclosed in IPALCO’s 2015 Form 10-K that was filed with the SEC on February 23, 2016. No other updates have been made to what was previously disclosed in IPALCO's 2015 Form 10-K that was filed with the SEC on February 23, 2016 other than the above mentioned balance sheet updates and updates to our Report of Independent Registered Accounting Firm to reflect a dual dated opinion as a result of these updates.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Retrospective Adoption of ASU 2015-03	RETROSPECTIVE ADOPTION OF ASU 2015-03 As discussed in Note 1, “ Overview and Summary of Significant Accounting Policies ,” ASU 2015-03 simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. As a result of the retrospective adoption of ASU 2015-03 effective January 1, 2016, deferred financing costs of approximately $13.9 million and $10.7 million previously classified within Deferred Debits were reclassified to reduce the related debt liabilities as of December 31, 2015 and 2014, respectively. Accordingly, the accompanying Consolidated Balance Sheets have been updated. However, Note 7, “ Debt ,” remains unchanged from what was previously disclosed in IPALCO’s 2015 Form 10-K that was filed with the SEC on February 23, 2016. No other updates have been made to what was previously disclosed in IPALCO's 2015 Form 10-K that was filed with the SEC on February 23, 2016 other than the above mentioned balance sheet updates and updates to our Report of Independent Registered Accounting Firm to reflect a dual dated opinion as a result of these updates.

Schedule I - Condensed Financia

Schedule I - Condensed Financial Information Of Registrant	12 Months Ended
	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Schedule I - Condensed Financial Information Of Registrant	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Accounting for Subsidiaries and Affiliates – IPALCO has accounted for the earnings of its subsidiaries on the equity method in the unconsolidated condensed financial information. EQUITY Equity Transactions On December 15, 2014, AES announced that it entered into an agreement with CDPQ, a long-term institutional investor headquartered in Quebec, Canada. Pursuant to the agreement, on February 11, 2015 CDPQ purchased from AES 15% of AES U.S. Investments and 100 shares of IPALCO’s common stock were issued to CDPQ. In addition, CDPQ agreed to invest approximately $349 million in IPALCO through 2016, in exchange for a 17.65% equity stake, funding existing growth and environmental projects at IPL. After completion of these transactions, CDPQ’s direct and indirect interests in IPALCO will total 30% , AES will own 85% of AES U.S. Investments, and AES U.S. Investments will own 82.35% of IPALCO. There will be no significant change in management or operational control of AES U.S. Investments, IPALCO or IPL as a result of these transactions. In connection with the initial closing under the agreement, CDPQ, AES U.S. Investments, and IPALCO entered into a Shareholders’ Agreement. The Shareholders’ Agreement established the general framework governing the relationship between and among CDPQ and AES U.S. Investments, and their respective successors and transferees, as shareholders of IPALCO. Pursuant to the Shareholders’ Agreement, the board of directors of IPALCO will initially consist of 11 directors, two nominated by CDPQ and 9 nominated by AES U.S. Investments. The Shareholders’ Agreement contains restrictions on IPALCO making certain major decisions without the prior affirmative vote of a majority of the board of directors of IPALCO. In addition, for so long as CDPQ holds at least 5% of IPALCO’s common shares, CDPQ will have review and consultation rights with respect to certain actions of IPALCO. Certain transfer restrictions and other transfer rights apply to CDPQ and AES U.S. Investments under the Shareholders’ Agreement, including certain rights of first offer, drag along rights, tag along rights, put rights and rights of first refusal. On February 11, 2015, in connection with the initial closing under the Subscription Agreement and the entry into the Shareholders’ Agreement, IPALCO submitted the Third Amended and Restated Articles of Incorporation for filing with the Indiana Secretary of State, as approved and adopted by the IPALCO Board. The purpose of the Third Amended and Restated Articles of Incorporation is to amend, among other things, Article VI of the Second Amended and Restated Articles of Incorporation of IPALCO in order to effectuate changes to the size and composition of the IPALCO Board in furtherance of the terms and conditions of the IPALCO Shareholder’s Agreement. Paid In Capital and Capital Stock On June 27, 2014, and July 31, 2013, IPALCO received equity capital contributions of $106.4 million and $49.1 million , respectively, from AES for funding needs related to IPL’s environmental and replacement generation projects. IPALCO then made the same equity capital contributions to IPL. On April 1, 2015, IPALCO issued and sold 11,818,828 shares of IPALCO's common stock to CDPQ for $214.4 million for funding needs primarily related to IPL's environmental construction program. IPALCO then made the same investment in IPL. As a result of this transaction, CDPQ's direct ownership interest in IPALCO is 11.6% and CDPQ's combined direct and indirect ownership interest in IPALCO is 24.9% . DEBT The following table presents IPALCO’s long-term indebtedness: December 31, Series Due 2015 2014 (In Thousands) Long-Term Debt 7.25% Senior Secured Notes April 2016 $ — $ 400,000 5.00% Senior Secured Notes May 2018 400,000 400,000 3.45% Senior Secured Notes July 2020 — 405,000 — Unamortized discount – net (371 ) (1,347 ) Total Long-term Debt 804,629 798,653 Less: Current Portion of Long-term Debt — — Net Long-term Debt $ 804,629 $ 798,653 Long-term Debt IPALCO’s Senior Secured Notes In June 2015, IPALCO completed the sale of the 2020 IPALCO Notes pursuant to Rule 144A and Regulation S under the Securities Act. The 2020 IPALCO Notes were issued pursuant to an Indenture dated June 25, 2015, by and between IPALCO and U.S. Bank, National Association, as trustee. The 2020 IPALCO Notes were priced to the public at 99.929% of the principal amount. Net proceeds to IPALCO were approximately $399.5 million after deducting underwriting costs and estimated offering expenses. These costs are being amortized to the maturity date using the effective interest method. We used the net proceeds from this offering to fund the purchase of the 2016 IPALCO Notes validly tendered and to pay for a related consent solicitation, to redeem any 2016 IPALCO Notes that remained outstanding after the completion of the tender, and to pay certain related fees, expenses and make-whole premiums. Of the 2016 IPALCO Notes outstanding, $366.5 million were tendered in June 2015. The remainder, $33.5 million , was redeemed in July 2015. An early tender premium was paid related to the tender offer and a redemption premium was paid related to the redemption of the 2016 IPALCO Notes. A loss on early extinguishment of debt of $22.1 million for the 2016 IPALCO Notes is included as a separate line item in the accompanying Unconsolidated Statements of Income. The 2020 IPALCO Notes are secured by IPALCO's pledge of all of the outstanding common stock of IPL. The lien on the pledged shares is shared equally and ratably with IPALCO's existing senior secured notes. IPALCO has entered into a Pledge Agreement Supplement with the Bank of New York Mellon Trust Company, N.A., as Collateral Agent, dated June 25, 2015, to the Pledge Agreement between IPALCO and The Bank of New York Mellon Trust Company, N.A., dated November 14, 2001, as supplemented by a Pledge Agreement Supplement dated April 15, 2008 and a Pledge Agreement Supplement dated May 18, 2011, each by IPALCO in favor of the Collateral Agent. IPALCO also agreed to register the 2020 IPALCO Notes under the Securities Act by filing an exchange offer registration statement or, under specified circumstances, a shelf registration statement with the SEC pursuant to a Registration Rights Agreement that IPALCO entered into with J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC, as representatives of the initial purchasers of the 2020 IPALCO Notes. IPALCO filed its registration statement on Form S-4 with respect to the 2020 IPALCO Notes with the SEC on September 28, 2015, and this registration statement was declared effective on October 15, 2015. The exchange offer was completed on November 16, 2015. The 2018 IPALCO Notes and 2020 IPALCO Notes are secured by IPALCO’s pledge of all of the outstanding common stock of IPL. RETROSPECTIVE ADOPTION OF ASU 2015-03 ASU 2015-03 simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. As a result of the retrospective adoption of ASU 2015-03 effective January 1, 2016, deferred financing costs of approximately $6.9 million and $4.6 million previously classified within Other Assets were reclassified to reduce the related debt liabilities as of December 31, 2015 and 2014, respectively. Accordingly, the accompanying Unconsolidated Balance Sheets have been updated. However, Note 3, “ Debt ,” remains unchanged from what was previously disclosed in IPALCO’s 2015 Form 10-K that was filed with the SEC on February 23, 2016. No other updates have been made to what was previously disclosed in IPALCO's 2015 Form 10-K that was filed with the SEC on February 23, 2016 other than the above mentioned balance sheet updates and updates to our Report of Independent Registered Accounting Firm to reflect a dual dated opinion as a result of these updates.

Schedule II - Valuation And Qua

Schedule II - Valuation And Qualifying Accounts And Reserves	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation And Qualifying Accounts And Reserves	IPALCO ENTERPRISES, INC. and SUBSIDIARIES Valuation and Qualifying Accounts and Reserves Years ended December 31, 2015, 2014 and 2013 (In Thousands) Column A – Description Column B Column C – Additions Column D – Deductions Column E Balance at Beginning Charged to Charged to Other Net Balance at Year ended December 31, 2015 Accumulated Provisions Deducted from Assets – Doubtful Accounts $ 2,076 $ 4,273 $ — $ 3,851 $ 2,498 Year ended December 31, 2014 Accumulated Provisions Deducted from Assets – Doubtful Accounts $ 1,982 $ 4,852 $ — $ 4,758 $ 2,076 Year ended December 31, 2013 Accumulated Provisions Deducted from Assets –Doubtful Accounts $ 2,047 $ 3,790 $ — $ 3,855 $ 1,982 INDIANAPOLIS POWER & LIGHT COMPANY and SUBSIDIARY Valuation and Qualifying Accounts and Reserves Years ended December 31, 2015, 2014 and 2013 (In Thousands) Column A – Description Column B Column C – Additions Column D – Deductions Column E Balance at Beginning Charged to Charged to Other Net Balance at Year ended December 31, 2015 Accumulated Provisions Deducted from Assets – Doubtful Accounts $ 2,076 $ 4,273 $ — $ 3,851 $ 2,498 Year ended December 31, 2014 Accumulated Provisions Deducted from Assets – Doubtful Accounts $ 1,982 $ 4,852 $ — $ 4,758 $ 2,076 Year ended December 31, 2013 Accumulated Provisions Deducted from Assets –Doubtful Accounts $ 2,047 $ 3,790 $ — $ 3,855 $ 1,982

Overview and Summary of Signi22

Overview and Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Principles of Consolidation	Principles of Consolidation IPALCO’s consolidated financial statements are prepared in accordance with GAAP and in conjunction with the rules and regulations of the SEC. The consolidated financial statements include the accounts of IPALCO, its regulated utility subsidiary, IPL, and its unregulated subsidiary, Mid-America. All intercompany items have been eliminated in consolidation. Certain costs for shared resources amongst IPL and IPALCO, such as labor and benefits, are allocated to each entity based on allocation methodologies that management believes to be reasonable. We have evaluated subsequent events through the date this report is issued. All income of Mid-America, as well as nonoperating income of IPL, are included below UTILITY OPERATING INCOME in the accompanying Consolidated Statements of Income.
Use of Management Estimates	Use of Management Estimates The preparation of financial statements in conformity with GAAP requires that management make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. The reported amounts of revenues and expenses during the reporting period may also be affected by the estimates and assumptions management is required to make. Actual results may differ from those estimates.
Reclassifications	Reclassifications Certain prior period amounts have been reclassified to conform to the current year presentation.
Regulation	Regulatory Accounting The retail utility operations of IPL are subject to the jurisdiction of the IURC. IPL’s wholesale power transactions are subject to the jurisdiction of the FERC. These agencies regulate IPL’s utility business operations, tariffs, accounting, depreciation allowances, services, issuances of securities and the sale and acquisition of utility properties. The financial statements of IPL are based on GAAP, including the provisions of FASB ASC 980 “Regulated Operations,” which gives recognition to the ratemaking and accounting practices of these agencies.
Revenues and Accounts Receivable	Revenues and Accounts Receivable Revenues related to the sale of energy are generally recognized when service is rendered or energy is delivered to customers. However, the determination of the energy sales to individual customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to certain customers since the date of the last meter reading are estimated and the corresponding unbilled revenue is accrued. In making its estimates of unbilled revenue, IPL uses complex models that consider various factors including daily generation volumes; known amounts of energy usage by nearly all residential, small commercial and industrial customers; estimated line losses; and estimated customer rates based on prior period billings. Given the use of these models, and that customers are billed on a monthly cycle, we believe it is unlikely that materially different results will occur in future periods when revenue is billed. At December 31, 2015 and 2014 , customer accounts receivable include unbilled energy revenues of $42.1 million and $48.4 million , respectively, on a base of annual revenue of $ 1.3 billion in 2015 and 2014 . An allowance for potential credit losses is maintained and amounts are written off when normal collection efforts have been exhausted. Our provision for doubtful accounts included in “Other operating expenses” on the accompanying Consolidated Statements of Income was $4.3 million , $4.9 million and $ 3.8 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. IPL’s basic rates include a provision for fuel costs as established in IPL’s most recent rate proceeding, which last adjusted IPL’s rates in 1996. IPL is permitted to recover actual costs of purchased power and fuel consumed, subject to certain restrictions. This is accomplished through quarterly FAC proceedings, in which IPL estimates the amount of fuel and purchased power costs in future periods. Through these proceedings, IPL is also permitted to recover, in future rates, underestimated fuel and purchased power costs from prior periods, subject to certain restrictions, and therefore the over or underestimated costs are deferred or accrued and amortized into fuel expense in the same period that IPL’s rates are adjusted. See also Note 2, “ Regulatory Matters ,” for a discussion of other costs that IPL is permitted to recover through periodic rate adjustment proceedings and the status of current rate adjustment proceedings. In addition, we are one of many transmission system owner members of MISO, a regional transmission organization which maintains functional control over the combined transmission systems of its members and manages one of the largest energy markets in the U.S. In the MISO market, IPL offers its generation and bids its demand into the market on an hourly basis. MISO settles these hourly offers and bids based on locational marginal prices, which is pricing for energy at a given location based on a market clearing price that takes into account physical limitations, generation, and demand throughout the MISO region. MISO evaluates the market participants’ energy offers and demand bids to economically and reliably dispatch the entire MISO system. IPL accounts for these hourly offers and bids, on a net basis, in UTILITY OPERATING REVENUES when in a net selling position and in UTILITY OPERATING EXPENSES – Power Purchased when in a net purchasing position.
Contingencies	Contingencies IPALCO accrues for loss contingencies when the amount of the loss is probable and estimable. IPL is subject to various environmental regulations, and is involved in certain legal proceedings. If IPL’s actual environmental and/or legal obligations are different from our estimates, the recognition of the actual amounts may have a material impact on our results of operations, financial condition and cash flows; although that has not been the case during the periods covered by this report. As of December 31, 2015 and 2014 , total loss contingencies accrued were $5.6 million and $5.2 million , respectively, which were included in “Other Current Liabilities” on the accompanying Consolidated Balance Sheets.
Concentration of Risk	Concentrations of Risk Substantially all of IPL’s customers are located within the Indianapolis area. In addition, approximately 65% of IPL’s full-time employees are covered by collective bargaining agreements in two bargaining units: a physical unit and a clerical-technical unit. IPL’s contract with the physical unit expires on December 10, 2018 , and the contract with the clerical-technical unit expires February 20, 2017 . Additionally, IPL has long-term coal contracts with four suppliers, with about 53% of our existing coal under contract for the three-year period ending December 31, 2018 coming from one supplier. Substantially all of the coal is currently mined in the state of Indiana.
Allowance For Funds Used During Construction	Allowance For Funds Used During Construction In accordance with the Uniform System of Accounts prescribed by FERC, IPL capitalizes an allowance for the net cost of funds (interest on borrowed funds and a reasonable rate of return on equity funds) used for construction purposes during the period of construction with a corresponding credit to income. IPL capitalized amounts using pretax composite rates of 8.1% , 8.3% and 8.6% during 2015 , 2014 and 2013 , respectively. For the Eagle Valley CCGT, Harding Street refueling projects, and NPDES projects, IPL capitalized amounts using a pretax composite rate of 7.3% and 7.6% during 2015 and 2014, respectively.
Utility Plant and Depreciation	Utility Plant and Depreciation Utility plant is stated at original cost as defined for regulatory purposes. The cost of additions to utility plant and replacements of retirement units of property are charged to plant accounts. Units of property replaced or abandoned in the ordinary course of business are retired from the plant accounts at cost; such amounts, less salvage, are charged to accumulated depreciation. Depreciation is computed by the straight-line method based on functional rates approved by the IURC and averaged 4.2% , 4.1% , and 4.0% during 2015 , 2014 and 2013 , respectively. Depreciation expense was $198.8 million , $185.9 million , and $180.0 million for the years ended December 31, 2015 , 2014 and 2013 , respectively, which includes depreciation expense that has been deferred as a regulatory asset.
Derivatives	Derivatives We have only limited involvement with derivative financial instruments and do not use them for trading purposes. IPALCO accounts for its derivatives in accordance with ASC 815 “Derivatives and Hedging.” In addition, IPL has entered into contracts involving the physical delivery of energy and fuel. Because these contracts qualify for the normal purchases and normal sales scope exception in ASC 815, IPL has elected to account for them as accrual contracts, which are not adjusted for changes in fair value.
Fuel, Materials and Supplies	Fuel, Materials and Supplies We maintain coal, fuel oil, materials and supplies inventories for use in the production of electricity. These inventories are accounted for at the lower of cost or market, using the average cost.
Impairment of Long-Lived Assets	Impairment of Long-lived Assets GAAP requires that we measure long-lived assets for impairment when indicators of impairment exist. If an asset is deemed to be impaired, we are required to write down the asset to its fair value with a charge to current earnings. The net book value of our utility plant assets was $3.5 billion and $2.9 billion as of December 31, 2015 and 2014 , respectively. We do not believe any of these assets are currently impaired. In making this assessment, we consider such factors as: the overall condition and generating and distribution capacity of the assets; the expected ability to recover additional expenditures in the assets, such as CCT projects; the anticipated demand and relative pricing of retail electricity in our service territory and wholesale electricity in the region; and the cost of fuel.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of the existing assets and liabilities, and their respective income tax bases. The Company establishes a valuation allowance when it is more likely than not that all or a portion of a deferred tax asset will not be realized. The Company’s tax positions are evaluated under a more likely than not recognition threshold and measurement analysis before they are recognized for financial statement reporting. Uncertain tax positions have been classified as noncurrent income tax liabilities unless expected to be paid within one year. The Company’s policy for interest and penalties is to recognize interest and penalties as a component of the provision for income taxes in the Consolidated Statements of Operations. Income taxes payable which are includable in allowable costs for ratemaking purposes in future years are recorded as regulatory assets with a corresponding deferred tax liability. Investment tax credits that reduced federal income taxes in the years they arose have been deferred and are being amortized to income over the useful lives of the properties in accordance with regulatory treatment.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents are stated at cost, which approximates fair value. All highly liquid short-term investments with original maturities of three months or less are considered cash equivalents.
Pension and Postretirement Benefits	Pension and Postretirement Benefits We recognize in our Consolidated Balance Sheets an asset or liability reflecting the funded status of pension and other postretirement plans with current-year changes in the funded status, that would otherwise be recognized in AOCI, recorded as a regulatory asset as this can be recovered through future rates. All plan assets are recorded at fair value. We follow the measurement date provisions of the accounting guidance, which require a year-end measurement date of plan assets and obligations for all defined benefit plans. We account for and disclose pension and postretirement benefits in accordance with the provisions of GAAP relating to the accounting for pension and other postretirement plans. These GAAP provisions require the use of assumptions, such as the discount rate for liabilities and long-term rate of return on assets, in determining the obligations, annual cost and funding requirements of the plans. Effective January 1, 2016, we will apply a disaggregated discount rate approach for determining service cost and interest cost for our defined benefit pension plans and postretirement plans. This approach is consistent with the requirements of ASC 715 and is considered to be preferential to the aggregated single rate discount approach, which has historically been used in the U.S., because it is more consistent with the philosophy of a full yield curve valuation. The change in discount rate approach did not have an impact on the measurement of the benefit obligations at December 31, 2015, nor will it impact future remeasurements. This change in approach will impact the service cost and interest cost recorded in 2016 and future years. It will also impact the actuarial gains and losses recorded in future years, as well as the amortization thereof.
Repair and Maintenance Costs	Repair and Maintenance Costs Repair and maintenance costs are expensed as incurred.
Per Share Data	Per Share Data IPALCO is owned by AES U.S. Investments and CDPQ, IPALCO’s minority interest holder. IPALCO does not report earnings on a per-share basis.
New Accounting Pronouncements	New Accounting Pronouncements ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) In May 2014, the FASB issued ASU No. 2014-09 which clarifies principles for recognizing revenue and will result in a common revenue standard for GAAP and International Financial Reporting Standards. The objective of the new standard is to provide a single and comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. The standard requires an entity to recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14 , Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date, which deferred the effective date of ASU 2014-09 by one year, resulting in the new revenue standard being effective for annual reporting periods beginning after December 15, 2017 and interim periods therein. Early adoption is now permitted only as of the original effective date for public entities (that is, no earlier than 2017 for calendar year-end entities). The standard permits the use of either a full retrospective or modified retrospective approach. The Company has not yet selected a transition method and is currently evaluating the impact of adopting the standard on its consolidated financial statements. ASU No. 2015-02, Consolidation - Amendments to the Consolidation Analysis (Topic 810) In February 2015, the FASB issued ASU 2015-02, which makes targeted amendments to the current consolidation guidance and ends the deferral granted to investment companies from applying the VIE guidance. The standard amends the evaluation of whether (1) fees paid to a decision-maker or service providers represent a variable interest, (2) a limited partnership or similar entity has the characteristics of a VIE and (3) a reporting entity is the primary beneficiary of a VIE. The standard is effective for annual periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The Company does not expect this standard to have an impact on its consolidated financial statements upon adoption. ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30) In April 2015, the FASB issued ASU No. 2015-03, which simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this update. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein, and requires the use of the full retrospective approach. Early adoption is permitted for financial statements that have not been previously issued. As of December 31, 2015, the Company had approximately $20.8 million in deferred financing costs classified in other noncurrent assets that would be reclassified to reduce the related debt liabilities upon adoption of ASU No. 2015-03. ASU No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement In April 2015, the FASB issued ASU No. 2015-05, which clarifies how customers in cloud computing arrangements should determine whether the arrangement includes a software license and eliminates the existing requirement for customers to account for software licenses they acquired by analogizing to the accounting guidance on leases. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The standard permits the use of a prospective or retrospective approach. The Company expects to utilize the prospective approach upon adoption of this standard, which is not expected to have a material impact on its consolidated financial statements. ASU No. 2015-11, Simplifying the Measurement of Inventory (Topic 330) In July 2015, the FASB issued ASU No. 2015-11, which simplifies the subsequent measurement of inventory. It replaces the current lower of cost or market test with a lower of cost or net realizable value test. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. Early adoption is permitted. The new guidance must be applied prospectively. As the Company already uses the net realizable value to make lower of cost or market determinations, there will be no impact on its consolidated financial statements upon adoption of this standard. ASU No. 2015-15, Interest - Imputation of Interest (Subtopic 835-30) : Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements In August 2015, the FASB issued ASU No. 2015-15, which clarifies that the SEC Staff would not object to an entity presenting debt issuance costs related to line-of-credit arrangements as an asset that is subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. This standard should be adopted concurrent with adoption of ASU 2015-03 (which is described above). As of December 31, 2015, the Company had deferred financing costs related to lines of credit of approximately $0.3 million recorded within Deferred Debits that would not be reclassified upon adoption of this standard. ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments In September 2015, the FASB issued ASU 2015-16, which simplifies the measurement-period adjustments in business combinations. It eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. An acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The standard is effective for public entities for annual reporting periods beginning after December 15, 2015, and interim periods therein. Early adoption is permitted for financial statements that have not been issued. The new guidance should be applied prospectively to adjustments to provisional amounts that occur after the effective date of this standard. The Company will adopt this standard on January 1, 2016, which is not expected to have a material impact on the Company's consolidated financial statements. ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes Effective December 31, 2015, the Company prospectively adopted ASU No. 2015-17, which requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. As a result, each jurisdiction will now only have one net noncurrent deferred tax asset or liability. The guidance does not change the existing requirement that only permits offsetting within a jurisdiction; that is, companies will remain prohibited from offsetting deferred tax liabilities from one jurisdiction against deferred tax assets of another jurisdiction. Additionally, the current requirement that deferred tax liabilities and assets of a tax-paying component of an entity be offset and presented as a single amount is not affected by the update. As the Company elected to apply this ASU prospectively, prior periods were not adjusted. ASU No. 2016-01, Financial Instruments - Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, which was designed to improve the recognition and measurement of financial instruments through targeted changes to existing GAAP. The guidance requires equity investments (except those that are accounted for under the equity method of accounting or result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; that entities use the exit price notion when measuring financial instrument fair values; that an entity separate presentation of financial assets and liabilities by measurement category and form of financial asset on the Balance Sheets or Notes to the financial statements; that an entity present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk (or “ own credit ” ) when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. Also, the standard eliminates the requirement for public entities to disclose the methods and significant assumptions used to estimate the fair value required to be disclosed for financial instruments measured at amortized cost on the Balance Sheets. The standard is effective beginning with interim periods starting after December 31, 2017 and cannot be applied early. The Company is currently evaluating the applicability and materiality of the standard, but doesn't anticipate a material impact on the Company's consolidated financial statements.
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Principles of Consolidation	Principles of Consolidation IPL’s consolidated financial statements are prepared in accordance with GAAP and in conjunction with the rules and regulations of the SEC. The consolidated financial statements include the accounts of IPL and its unregulated subsidiary, IPL Funding. All intercompany items have been eliminated in consolidation. Certain costs for shared resources amongst IPL and IPALCO, such as labor and benefits, are allocated to each entity based on allocation methodologies that management believes to be reasonable. We have evaluated subsequent events through the date this report is issued.
Use of Management Estimates	Use of Management Estimates The preparation of financial statements in conformity with GAAP requires that management make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. The reported amounts of revenues and expenses during the reporting period may also be affected by the estimates and assumptions management is required to make. Actual results may differ from those estimates.
Reclassifications	Reclassifications Certain prior period amounts have been reclassified to conform to the current year presentation.
Regulation	Regulatory Accounting The retail utility operations of IPL are subject to the jurisdiction of the IURC. IPL’s wholesale power transactions are subject to the jurisdiction of the FERC. These agencies regulate IPL’s utility business operations, tariffs, accounting, depreciation allowances, services, issuances of securities and the sale and acquisition of utility properties. The financial statements of IPL are based on GAAP, including the provisions of FASB ASC 980 “Regulated Operations,” which gives recognition to the ratemaking and accounting practices of these agencies. See also Note 5, “Regulatory Assets and Liabilities” for a discussion of specific regulatory assets and liabilities.
Revenues and Accounts Receivable	Revenues and Accounts Receivable Revenues related to the sale of energy are generally recognized when service is rendered or energy is delivered to customers. However, the determination of the energy sales to individual customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. At the end of each month, amounts of energy delivered to certain customers since the date of the last meter reading are estimated and the corresponding unbilled revenue is accrued. In making its estimates of unbilled revenue, IPL uses complex models that consider various factors including daily generation volumes; known amounts of energy usage by nearly all residential, small commercial and industrial customers; estimated line losses; and estimated customer rates based on prior period billings. Given the use of these models, and that customers are billed on a monthly cycle, we believe it is unlikely that materially different results will occur in future periods when revenue is billed. At December 31, 2015 and 2014 , customer accounts receivable include unbilled energy revenues of $42.1 million and $48.4 million , respectively, on a base of annual revenue of $1.3 billion in 2015 and 2014 . An allowance for potential credit losses is maintained and amounts are written off when normal collection efforts have been exhausted. Our provision for doubtful accounts included in “ Other operating expenses” on the accompanying Consolidated Statements of Income was $4.3 million , $4.9 million and $3.8 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. IPL’s basic rates include a provision for fuel costs as established in IPL’s most recent rate proceeding, which last adjusted IPL’s rates in 1996. IPL is permitted to recover actual costs of purchased power and fuel consumed, subject to certain restrictions. This is accomplished through quarterly FAC proceedings, in which IPL estimates the amount of fuel and purchased power costs in future periods. Through these proceedings, IPL is also permitted to recover, in future rates, underestimated fuel and purchased power costs from prior periods, subject to certain restrictions, and therefore the over or underestimated costs are deferred or accrued and amortized into fuel expense in the same period that IPL’s rates are adjusted. See also Note 2, “ Regulatory Matters ,” for a discussion of other costs that IPL is permitted to recover through periodic rate adjustment proceedings and the status of current rate adjustment proceedings. In addition, we are one of many transmission system owner members of MISO, a regional transmission organization which maintains functional control over the combined transmission systems of its members and manages one of the largest energy markets in the U.S. In the MISO market, IPL offers its generation and bids its demand into the market on an hourly basis. MISO settles these hourly offers and bids based on locational marginal prices, which is pricing for energy at a given location based on a market clearing price that takes into account physical limitations, generation, and demand throughout the MISO region. MISO evaluates the market participants’ energy offers and demand bids to economically and reliably dispatch the entire MISO system. IPL accounts for these hourly offers and bids, on a net basis, in OPERATING REVENUES when in a net selling position and in OPERATING EXPENSES – Power Purchased when in a net purchasing position.
Contingencies	Contingencies IPL accrues for loss contingencies when the amount of the loss is probable and estimable. IPL is subject to various environmental regulations, and is involved in certain legal proceedings. If IPL’s actual environmental and/or legal obligations are different from our estimates, the recognition of the actual amounts may have a material impact on our results of operations, financial condition and cash flows; although that has not been the case during the periods covered by this report. As of December 31, 2015 and 2014 , total loss contingencies accrued were $5.6 million and $5.2 million , respectively, which were included in “ Other Current Liabilities” on the accompanying Consolidated Balance Sheets.
Concentration of Risk	Concentrations of Risk Substantially all of IPL’s customers are located within the Indianapolis area. In addition, approximately 65% of IPL’s full-time employees are covered by collective bargaining agreements in two bargaining units: a physical unit and a clerical-technical unit. IPL’s contract with the physical unit expires on December 10, 2018 , and the contract with the clerical-technical unit expires February 20, 2017 . Additionally, IPL has long-term coal contracts with four suppliers, with about 53% of our existing coal under contract for the three-year period ending December 31, 2018 coming from one supplier. Substantially all of the coal is currently mined in the state of Indiana.
Allowance For Funds Used During Construction	Allowance For Funds Used During Construction In accordance with the Uniform System of Accounts prescribed by FERC, IPL capitalizes an allowance for the net cost of funds (interest on borrowed funds and a reasonable rate of return on equity funds) used for construction purposes during the period of construction with a corresponding credit to income. IPL capitalized amounts using pretax composite rates of 8.1% , 8.3% and 8.6% during 2015 , 2014 and 2013 , respectively. For the Eagle Valley CCGT, Harding Street refueling projects, and NPDES projects, IPL capitalized amounts using a pretax composite rate of 7.3% and 7.6% during 2015 and 2014, respectively.
Utility Plant and Depreciation	Utility Plant and Depreciation Utility plant is stated at original cost as defined for regulatory purposes. The cost of additions to utility plant and replacements of retirement units of property are charged to plant accounts. Units of property replaced or abandoned in the ordinary course of business are retired from the plant accounts at cost; such amounts, less salvage, are charged to accumulated depreciation. Depreciation is computed by the straight-line method based on functional rates approved by the IURC and averaged 4.2% , 4.1% , and 4.0% during 2015 , 2014 and 2013 , respectively. Depreciation expense was $198.8 million , $185.9 million , and $180.0 million for the years ended December 31, 2015 , 2014 and 2013 , respectively, which includes depreciation expense that has been deferred as a regulatory asset.
Derivatives	Derivatives We have only limited involvement with derivative financial instruments and do not use them for trading purposes. IPL accounts for its derivatives in accordance with ASC 815 “Derivatives and Hedging.” In addition, IPL has entered into contracts involving the physical delivery of energy and fuel. Because these contracts qualify for the normal purchases and normal sales scope exception in ASC 815, IPL has elected to account for them as accrual contracts, which are not adjusted for changes in fair value.
Fuel, Materials and Supplies	Fuel, Materials and Supplies We maintain coal, fuel oil, materials and supplies inventories for use in the production of electricity. These inventories are accounted for at the lower of cost or market, using the average cost.
Impairment of Long-Lived Assets	Impairment of Long-lived Assets GAAP requires that we measure long-lived assets for impairment when indicators of impairment exist. If an asset is deemed to be impaired, we are required to write down the asset to its fair value with a charge to current earnings. The net book value of our utility plant assets was $3.5 billion and $2.9 billion as of December 31, 2015 and 2014 , respectively. We do not believe any of these assets are currently impaired. In making this assessment, we consider such factors as: the overall condition and generating and distribution capacity of the assets; the expected ability to recover additional expenditures in the assets, such as CCT projects; the anticipated demand and relative pricing of retail electricity in our service territory and wholesale electricity in the region; and the cost of fuel.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of the existing assets and liabilities, and their respective income tax bases. The Company establishes a valuation allowance when it is more likely than not that all or a portion of a deferred tax asset will not be realized. The Company’s tax positions are evaluated under a more likely than not recognition threshold and measurement analysis before they are recognized for financial statement reporting. Uncertain tax positions have been classified as noncurrent income tax liabilities unless expected to be paid within one year. The Company’s policy for interest and penalties is to recognize interest and penalties as a component of the provision for income taxes in the Consolidated Statements of Operations. Income taxes payable which are includable in allowable costs for ratemaking purposes in future years are recorded as regulatory assets with a corresponding deferred tax liability. Investment tax credits that reduced federal income taxes in the years they arose have been deferred and are being amortized to income over the useful lives of the properties in accordance with regulatory treatment.
Cash and Cash Equivalents	Cash and Cash Equivalents
Repair and Maintenance Costs	Repair and Maintenance Costs Repair and maintenance costs are expensed as incurred.
Per Share Data	Per Share Data IPALCO owns all of the outstanding common stock of IPL. IPL does not report earnings on a per-share basis.
New Accounting Pronouncements	New Accounting Pronouncements ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) In May 2014, the FASB issued ASU No. 2014-09 which clarifies principles for recognizing revenue and will result in a common revenue standard for GAAP and International Financial Reporting Standards. The objective of the new standard is to provide a single and comprehensive revenue recognition model for all contracts with customers to improve comparability. The revenue standard contains principles that an entity will apply to determine the measurement of revenue and timing of when it is recognized. The standard requires an entity to recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14 , Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date, which deferred the effective date of ASU 2014-09 by one year, resulting in the new revenue standard being effective for annual reporting periods beginning after December 15, 2017 and interim periods therein. Early adoption is now permitted only as of the original effective date for public entities (that is, no earlier than 2017 for calendar year-end entities). The standard permits the use of either a full retrospective or modified retrospective approach. The Company has not yet selected a transition method and is currently evaluating the impact of adopting the standard on its consolidated financial statements. ASU No. 2015-02, Consolidation - Amendments to the Consolidation Analysis (Topic 810) In February 2015, the FASB issued ASU 2015-02, which makes targeted amendments to the current consolidation guidance and ends the deferral granted to investment companies from applying the VIE guidance. The standard amends the evaluation of whether (1) fees paid to a decision-maker or service providers represent a variable interest, (2) a limited partnership or similar entity has the characteristics of a VIE and (3) a reporting entity is the primary beneficiary of a VIE. The standard is effective for annual periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The Company does not expect this standard to have an impact on its consolidated financial statements upon adoption. ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30) In April 2015, the FASB issued ASU No. 2015-03, which simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this update. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein, and requires the use of the full retrospective approach. Early adoption is permitted for financial statements that have not been previously issued. As of December 31, 2015, the Company had approximately $13.9 million in deferred financing costs classified in other noncurrent assets that would be reclassified to reduce the related debt liabilities upon adoption of ASU No. 2015-03. ASU No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement In April 2015, the FASB issued ASU No. 2015-05, which clarifies how customers in cloud computing arrangements should determine whether the arrangement includes a software license and eliminates the existing requirement for customers to account for software licenses they acquired by analogizing to the accounting guidance on leases. The standard is effective for annual reporting periods beginning after December 15, 2015 and interim periods therein. Early adoption is permitted. The standard permits the use of a prospective or retrospective approach. The Company expects to utilize the prospective approach upon adoption of this standard, which is not expected to have a material impact on its consolidated financial statements. ASU No. 2015-11, Simplifying the Measurement of Inventory (Topic 330) In July 2015, the FASB issued ASU No. 2015-11, which simplifies the subsequent measurement of inventory. It replaces the current lower of cost or market test with a lower of cost or net realizable value test. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. Early adoption is permitted. The new guidance must be applied prospectively. As the Company already uses the net realizable value to make lower of cost or market determinations, there will be no impact on its consolidated financial statements upon adoption of this standard. ASU No. 2015-15, Interest - Imputation of Interest (Subtopic 835-30) : Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements In August 2015, the FASB issued ASU No. 2015-15, which clarifies that the SEC Staff would not object to an entity presenting debt issuance costs related to line-of-credit arrangements as an asset that is subsequently amortized ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. This standard should be adopted concurrent with adoption of ASU 2015-03 (which is described above). As of December 31, 2015, the Company had deferred financing costs related to lines of credit of approximately $0.3 million recorded within Deferred Debits that would not be reclassified upon adoption of this standard. ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments In September 2015, the FASB issued ASU 2015-16, which simplifies the measurement-period adjustments in business combinations. It eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. An acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The standard is effective for public entities for annual reporting periods beginning after December 15, 2015, and interim periods therein. Early adoption is permitted for financial statements that have not been issued. The new guidance should be applied prospectively to adjustments to provisional amounts that occur after the effective date of this standard. The Company will adopt this standard on January 1, 2016, which is not expected to have a material impact on the Company's consolidated financial statements. ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes Effective December 31, 2015, the Company prospectively adopted ASU No. 2015-17, which requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. As a result, each jurisdiction will now only have one net noncurrent deferred tax asset or liability. The guidance does not change the existing requirement that only permits offsetting within a jurisdiction; that is, companies will remain prohibited from offsetting deferred tax liabilities from one jurisdiction against deferred tax assets of another jurisdiction. Additionally, the current requirement that deferred tax liabilities and assets of a tax-paying component of an entity be offset and presented as a single amount is not affected by the update. As the Company elected to apply this ASU prospectively, prior periods were not adjusted. ASU No. 2016-01, Financial Instruments - Overall (Topic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, which was designed to improve the recognition and measurement of financial instruments through targeted changes to existing GAAP. The guidance requires equity investments (except those that are accounted for under the equity method of accounting or result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; that entities use the exit price notion when measuring financial instrument fair values; that an entity separate presentation of financial assets and liabilities by measurement category and form of financial asset on the Balance Sheets or Notes to the financial statements; that an entity present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk (or “own credit ” ) when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. Also, the standard eliminates the requirement for public entities to disclose the methods and significant assumptions used to estimate the fair value required to be disclosed for financial instruments measured at amortized cost on the Balance Sheets. The standard is effective beginning with interim periods starting after December 31, 2017 and cannot be applied early. The Company is currently evaluating the applicability and materiality of the standard, but doesn't anticipate a material impact on the Company's consolidated financial statements.

Overview and Summary of Signi23

Overview and Summary of Significant Accounting Policies Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Schedule of Expected Service and Interest Costs	The impact of the change in approach on expected service costs in 2016 is shown below: $ in thousands Expected 2016 Service Cost Expected 2016 Interest Cost Disaggregated rate approach Aggregate rate approach Impact of change Disaggregated rate approach Aggregate rate approach Impact of change Pension $ 7,018 $ 7,382 $ (364 ) $ 25,634 $ 30,916 $ (5,282 )
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Schedule of Expected Service and Interest Costs	The impact of the change in approach on expected service costs in 2016 is shown below: $ in thousands Expected 2016 Service Cost Expected 2016 Interest Cost Disaggregated rate approach Aggregate rate approach Impact of change Disaggregated rate approach Aggregate rate approach Impact of change Pension $ 7,018 $ 7,382 $ (364 ) $ 25,634 $ 30,916 $ (5,282 )

Utility Plant In Service (Table

Utility Plant In Service (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Schedule Of Original Cost Of Utility Plant In Service	As of December 31, 2015 2014 (In Thousands) Production $ 3,111,674 $ 2,862,579 Transmission 293,767 268,594 Distribution 1,371,029 1,323,190 General plant 216,124 203,660 Total utility plant in service $ 4,992,594 $ 4,658,023
Reconciliation Of Asset Retirement Obligation Liability	The following is a reconciliation of the ARO legal liability year end balances: 2015 2014 (In Millions) Balance as of January 1 $ 59.1 $ 41.4 Liabilities incurred 0.6 — Liabilities settled (2.5 ) — Revisions in estimated cash flows (1.3 ) 15.4 Accretion expense 3.1 2.3 Balance as of December 31 $ 59.0 $ 59.1
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Schedule Of Original Cost Of Utility Plant In Service	As of December 31, 2015 2014 (In Thousands) Production $ 3,111,674 $ 2,862,579 Transmission 293,767 268,594 Distribution 1,371,029 1,323,190 General plant 216,124 203,660 Total utility plant in service $ 4,992,594 $ 4,658,023
Reconciliation Of Asset Retirement Obligation Liability	The following is a reconciliation of the ARO legal liability year end balances: 2015 2014 (In Millions) Balance as of January 1 $ 59.1 $ 41.4 Liabilities incurred 0.6 — Liabilities settled (2.5 ) — Revisions in estimated cash flows (1.3 ) 15.4 Accretion expense 3.1 2.3 Balance as of December 31 $ 59.0 $ 59.1

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Summary of Fair Value Assets and Liabilities Measured on a Recurring Basis, Level 3	The fair value of assets and liabilities at December 31, 2015 measured on a recurring basis and the respective category within the fair value hierarchy for IPALCO was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2015 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 4,150 $ — $ — $ 4,150 Total financial assets measured at fair value $ 4,150 $ — $ — $ 4,150 Financial liabilities: Other derivative liabilities $ 121 $ — $ — $ 121 Total financial liabilities measured at fair value $ 121 $ — $ — $ 121 The fair value of assets and liabilities at December 31, 2014 measured on a recurring basis and the respective category within the fair value hierarchy for IPALCO was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2014 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 6,235 $ — $ — $ 6,235 Total financial assets measured at fair value $ 6,235 $ — $ — $ 6,235 Financial liabilities: Other derivative liabilities $ 140 $ — $ — $ 140 Total financial liabilities measured at fair value $ 140 $ — $ — $ 140
Reconciliation of Financial Instruments Classified as Level 3	The following table sets forth a reconciliation of financial instruments, measured at fair value on a recurring basis, classified as Level 3 in the fair value hierarchy (note, amounts in this table indicate carrying values, which approximate fair values): Derivative Financial (In Thousands) Balance at January 1, 2014 $ 4,133 Unrealized gain recognized in earnings 16 Issuances 15,710 Settlements (13,764 ) Balance at December 31, 2014 $ 6,095 Unrealized gain recognized in earnings 47 Issuances 13,281 Settlements (15,394 ) Balance at December 31, 2015 $ 4,029
Schedule of Face and Fair Value of Debt	The following table shows the face value and the fair value of fixed-rate and variable-rate indebtedness (Level 2) for the periods ending: December 31, 2015 December 31, 2014 Face Value Fair Value Face Value Fair Value (In Millions) Fixed-rate $ 2,088.4 $ 2,225.3 $ 1,955.3 $ 2,231.2 Variable-rate 256.9 256.9 50.0 50.0 Total indebtedness $ 2,345.3 $ 2,482.2 $ 2,005.3 $ 2,281.2
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Summary of Fair Value Assets and Liabilities Measured on a Recurring Basis, Level 3	The fair value of assets and liabilities at December 31, 2015 measured on a recurring basis and the respective category within the fair value hierarchy for IPL was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2015 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 4,150 $ — $ — $ 4,150 Total financial assets measured at fair value $ 4,150 $ — $ — $ 4,150 Financial liabilities: Other derivative liabilities $ 121 $ — $ — $ 121 Total financial liabilities measured at fair value $ 121 $ — $ — $ 121 The fair value of assets and liabilities at December 31, 2014 measured on a recurring basis and the respective category within the fair value hierarchy for IPL was determined as follows: Assets and Liabilities at Fair Value Level 1 Level 2 Level 3 Fair value at December 31, 2014 Based on quoted market prices in active markets Other observable inputs Unobservable inputs (In Thousands) Financial assets: Financial transmission rights $ 6,235 $ — $ — $ 6,235 Total financial assets measured at fair value $ 6,235 $ — $ — $ 6,235 Financial liabilities: Other derivative liabilities $ 140 $ — $ — $ 140 Total financial liabilities measured at fair value $ 140 $ — $ — $ 140
Reconciliation of Financial Instruments Classified as Level 3	The following table sets forth a reconciliation of financial instruments, measured at fair value on a recurring basis, classified as Level 3 in the fair value hierarchy (note, amounts in this table indicate carrying values, which approximate fair values): Derivative Financial (In Thousands) Balance at January 1, 2014 $ 4,133 Unrealized gain recognized in earnings 16 Issuances 15,710 Settlements (13,764 ) Balance at December 31, 2014 $ 6,095 Unrealized gain recognized in earnings 47 Issuances 13,281 Settlements (15,394 ) Balance at December 31, 2015 $ 4,029
Schedule of Face and Fair Value of Debt	The following table shows the face value and the fair value of fixed-rate and variable-rate indebtedness (Level 2) for the periods ending: December 31, 2015 December 31, 2014 Face Value Fair Value Face Value Fair Value (In Millions) Fixed-rate $ 1,283.4 $ 1,406.8 $ 1,155.3 $ 1,386.2 Variable-rate 256.9 256.9 50.0 50.0 Total indebtedness $ 1,540.3 $ 1,663.7 $ 1,205.3 $ 1,436.2

Regulatory Assets And Liabili26

Regulatory Assets And Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Schedule Of Regulatory Assets And Liabilities	The amounts of regulatory assets and regulatory liabilities at December 31 are as follows: 2015 2014 Recovery Period (In Thousands) Regulatory Assets Current: Environmental projects $ 8,002 $ 93 Through 2016 (1) Total current regulatory assets $ 8,002 $ 93 Long-term: Unrecognized pension and other postretirement benefit plan costs $ 226,889 $ 229,590 Various Income taxes recoverable through rates 35,765 31,335 Various Deferred MISO costs 128,610 110,500 To be determined (2) Unamortized Petersburg Unit 4 carrying charges and certain other costs 11,248 12,302 Through 2026 (1) (3) Unamortized reacquisition premium on debt 23,268 24,585 Over remaining life of debt Environmental projects 16,876 7,671 Through 2021 (1) Other miscellaneous 5,544 3,210 To be determined (2) Total long-term regulatory assets $ 448,200 $ 419,193 Total regulatory assets $ 456,202 $ 419,286 Regulatory Liabilities Current: Deferred fuel $ 19,746 $ 17,837 Through 2016 (1) FTRs 4,150 6,235 Through 2016 (1) DSM program costs 4,273 2,001 Through 2016 (1) Environmental projects — 1,870 Through 2016 (1) Total current regulatory liabilities $ 28,169 $ 27,943 Long-term: ARO and accrued asset removal costs $ 637,065 $ 607,628 Not Applicable Unamortized investment tax credit 2,451 3,289 Through 2021 Total long-term regulatory liabilities $ 639,516 $ 610,917 Total regulatory liabilities $ 667,685 $ 638,860 (1) Recovered (credited) per specific rate orders (2) Recovery is probable but timing not yet determined (3) Recovered with a current return
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Schedule Of Regulatory Assets And Liabilities	The amounts of regulatory assets and regulatory liabilities at December 31 are as follows: 2015 2014 Recovery Period (In Thousands) Regulatory Assets Current: Environmental projects $ 8,002 $ 93 Through 2016 (1) Total current regulatory assets $ 8,002 $ 93 Long-term: Unrecognized pension and other postretirement benefit plan costs $ 226,889 $ 229,590 Various Income taxes recoverable through rates 35,765 31,335 Various Deferred MISO costs 128,610 110,500 To be determined (2) Unamortized Petersburg Unit 4 carrying charges and certain other costs 11,248 12,302 Through 2026 (1) (3) Unamortized reacquisition premium on debt 23,268 24,585 Over remaining life of debt Environmental projects 16,876 7,671 Through 2021 (1) Other miscellaneous 5,544 3,210 To be determined (2) Total long-term regulatory assets $ 448,200 $ 419,193 Total regulatory assets $ 456,202 $ 419,286 Regulatory Liabilities Current: Deferred fuel $ 19,746 $ 17,837 Through 2016 (1) FTRs 4,150 6,235 Through 2016 (1) DSM program costs 4,273 2,001 Through 2016 (1) Environmental projects — 1,870 Through 2016 (1) Total current regulatory liabilities $ 28,169 $ 27,943 Long-term: ARO and accrued asset removal costs $ 637,065 $ 607,628 Not Applicable Unamortized investment tax credit 2,451 3,289 Through 2021 Total long-term regulatory liabilities $ 639,516 $ 610,917 Total regulatory liabilities $ 667,685 $ 638,860 (1) Recovered (credited) per specific rate orders (2) Recovery is probable but timing not yet determined (3) Recovered with a current return

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Schedule Of Preferred Stock	At December 31, 2015 , 2014 and 2013 , preferred stock consisted of the following: December 31, 2015 December 31, Shares Call Price 2015 2014 2013 Par Value, plus premium, if applicable (In Thousands) Cumulative $100 par value, authorized 2,000,000 shares 4% Series 47,611 $ 118.00 $ 5,410 $ 5,410 $ 5,410 4.2% Series 19,331 103.00 1,933 1,933 1,933 4.6% Series 2,481 103.00 248 248 248 4.8% Series 21,930 101.00 2,193 2,193 2,193 5.65% Series 500,000 100.00 50,000 50,000 50,000 Total cumulative preferred stock 591,353 $ 59,784 $ 59,784 $ 59,784
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Schedule Of Preferred Stock	At December 31, 2015 , 2014 and 2013 , preferred stock consisted of the following: December 31, 2015 December 31, Shares Call Price 2015 2014 2013 Par Value, plus premium, if applicable (In Thousands) Cumulative $100 par value, authorized 2,000,000 shares 4% Series 47,611 $ 118.00 $ 5,410 $ 5,410 $ 5,410 4.2% Series 19,331 103.00 1,933 1,933 1,933 4.6% Series 2,481 103.00 248 248 248 4.8% Series 21,930 101.00 2,193 2,193 2,193 5.65% Series 500,000 100.00 50,000 50,000 50,000 Total cumulative preferred stock 591,353 $ 59,784 $ 59,784 $ 59,784

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Schedule Long-Term Indebtedness	The following table presents our long-term debt: December 31, Series Due 2015 2014 (In Thousands) IPL first mortgage bonds (see below): 4.90% (1) January 2016 $ — $ 30,000 4.90% (1) January 2016 — 41,850 4.90% (1) January 2016 — 60,000 5.40% (2) August 2017 24,650 24,650 3.875% (1) August 2021 55,000 55,000 3.875% (1) August 2021 40,000 40,000 4.55% (1) December 2024 40,000 40,000 6.60% January 2034 100,000 100,000 6.05% October 2036 158,800 158,800 6.60% June 2037 165,000 165,000 4.875% November 2041 140,000 140,000 4.65% June 2043 170,000 170,000 4.50% June 2044 130,000 130,000 4.70% September 2045 260,000 — Unamortized discount – net (4,242 ) (2,940 ) Total IPL first mortgage bonds 1,279,208 1,152,360 IPL unsecured debt: Variable (3) December 2020 30,000 — Variable (3) December 2020 60,000 — Total IPL unsecured debt 90,000 — Total Long-term Debt – IPL 1,369,208 1,152,360 Long-term Debt – IPALCO: 7.25% Senior Secured Notes April 2016 — 400,000 5.00% Senior Secured Notes May 2018 400,000 400,000 3.45% Senior Secured Notes July 2020 405,000 — Unamortized discount – net (371 ) (1,347 ) Total Long-term Debt – IPALCO 804,629 798,653 Total Consolidated IPALCO Long-term Debt 2,173,837 1,951,013 Less: Current Portion of Long-term Debt — — Net Consolidated IPALCO Long-term Debt $ 2,173,837 $ 1,951,013 (1) First mortgage bonds are issued to the Indiana Finance Authority, to secure the loan of proceeds from the tax-exempt bonds issued by the Indiana Finance Authority. (2) First mortgage bonds are issued to the city of Petersburg, Indiana, to secure the loan proceeds from various tax-exempt instruments issued by the city. (3) Unsecured notes are issued to the Indiana Finance Authority by IPL to facilitate the loan of proceeds from various tax-exempt notes issued by the Indiana Finance Authority. The notes have a final maturity date of December 2038, but are subject to a mandatory put in December 2020.
Schedule Of Maturities On Long-Term Indebtedness	Maturities on long-term indebtedness subsequent to December 31, 2015 , are as follows: Year Amount (In Thousands) 2016 $ — 2017 24,650 2018 400,000 2019 — 2020 495,000 Thereafter 1,258,800 Total $ 2,178,450
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Schedule Long-Term Indebtedness	The following table presents our long-term debt: December 31, Series Due 2015 2014 (In Thousands) IPL first mortgage bonds (see below): 4.90% (1) January 2016 $ — $ 30,000 4.90% (1) January 2016 — 41,850 4.90% (1) January 2016 — 60,000 5.40% (2) August 2017 24,650 24,650 3.875% (1) August 2021 55,000 55,000 3.875% (1) August 2021 40,000 40,000 4.55% (1) December 2024 40,000 40,000 6.60% January 2034 100,000 100,000 6.05% October 2036 158,800 158,800 6.60% June 2037 165,000 165,000 4.875% November 2041 140,000 140,000 4.65% June 2043 170,000 170,000 4.50% June 2044 130,000 130,000 4.70% September 2045 260,000 — Unamortized discount – net (4,242 ) (2,940 ) Total IPL first mortgage bonds 1,279,208 1,152,360 IPL unsecured debt: Variable (3) December 2020 30,000 — Variable (3) December 2020 60,000 — Total IPL unsecured debt 90,000 — Total Consolidated IPL Long-term Debt 1,369,208 1,152,360 Less: Current Portion of Long-term Debt — — Net Consolidated IPL Long-term Debt $ 1,369,208 $ 1,152,360 (1) First mortgage bonds are issued to the Indiana Finance Authority, to secure the loan of proceeds from the tax-exempt bonds issued by the Indiana Finance Authority. (2) First mortgage bonds are issued to the city of Petersburg, Indiana, to secure the loan proceeds from various tax-exempt instruments issued by the city. (3) Unsecured notes are issued to the Indiana Finance Authority by IPL to facilitate the loan of proceeds from various tax-exempt notes issued by the Indiana Finance Authority. The notes have a final maturity date of December 2038, but are subject to a mandatory put in December 2020.
Schedule Of Maturities On Long-Term Indebtedness	Maturities on long-term indebtedness subsequent to December 31, 2015 , are as follows: Year Amount (In Thousands) 2016 $ — 2017 24,650 2018 — 2019 — 2020 90,000 Thereafter 1,258,800 Total $ 1,373,450

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Schedule Of Federal And State Income Taxed Charged To Income	Federal and state income taxes charged to income are as follows: 2015 2014 2013 (In Thousands) Charged to utility operating expenses: Current income taxes: Federal $ 18,661 $ 944 $ 53,937 State 5,758 110 15,191 Total current income taxes 24,419 1,054 69,128 Deferred income taxes: Federal 29,165 58,114 (8,048 ) State 5,019 12,498 (1,031 ) Total deferred income taxes 34,184 70,612 (9,079 ) Net amortization of investment credit (1,319 ) (1,431 ) (1,501 ) Total charge to utility operating expenses 57,284 70,235 58,548 Charged to other income and deductions: Current income taxes: Federal (18,661 ) (459 ) (16,909 ) State (5,758 ) (5 ) (4,193 ) Total current income taxes (24,419 ) (464 ) (21,102 ) Deferred income taxes: Federal (2,573 ) (18,082 ) 246 State 1,274 (3,645 ) 50 Total deferred income taxes (1,299 ) (21,727 ) 296 Net provision to other income and deductions (25,718 ) (22,191 ) (20,806 ) Total federal and state income tax provisions $ 31,566 $ 48,044 $ 37,742
Schedule Of Effective Income Tax Rate	The reasons for the difference, stated as a percentage of pretax income, are as follows: 2015 2014 2013 Federal statutory tax rate 35.0 % 35.0 % 35.0 % State income tax, net of federal tax benefit 4.7 % 4.8 % 6.7 % Amortization of investment tax credits (1.5 )% (1.2 )% (1.5 )% Preferred dividends of subsidiary 1.3 % 0.9 % 1.1 % Depreciation flow through and amortization (0.3 )% (0.3 )% (0.3 )% Additional funds used during construction - equity (3.5 )% (0.3 )% 0.6 % Manufacturers’ Production Deduction (Sec. 199) — % — % (3.8 )% Other – net 0.2 % 0.2 % 0.5 % Effective tax rate 35.9 % 39.1 % 38.3 %
Schedule Of Deferred Tax Assets And Liabilities	The significant items comprising IPALCO’s net accumulated deferred tax liability recognized on the audited Consolidated Balance Sheets as of December 31, 2015 and 2014 , are as follows: 2015 2014 (In Thousands) Deferred tax liabilities: Relating to utility property, net $ 541,369 $ 539,318 Regulatory assets recoverable through future rates 178,187 161,697 Other 11,768 14,211 Total deferred tax liabilities 731,324 715,226 Deferred tax assets: Investment tax credit 1,507 2,019 Regulatory liabilities including ARO 260,555 247,118 Employee benefit plans 38,159 45,091 Net operating loss 23,161 51,364 Other 10,548 10,289 Total deferred tax assets 333,930 355,881 Net deferred tax liability 397,394 359,345 Less: deferred tax asset - current — (61,782 ) Deferred income taxes – net $ 397,394 $ 421,127
Reconciliation Of Unrecognized Tax Benefits	The following is a reconciliation of the beginning and ending amounts of unrecognized tax benefits for the years ended December 31, 2015 , 2014 and 2013 : 2015 2014 2013 (In Thousands) Unrecognized tax benefits at January 1 $ 7,042 $ 6,734 $ 6,138 Gross increases – current period tax positions 962 975 986 Gross decreases – prior period tax positions (857 ) (667 ) (390 ) Unrecognized tax benefits at December 31 $ 7,147 $ 7,042 $ 6,734
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Schedule Of Federal And State Income Taxed Charged To Income	Federal and state income taxes charged to income are as follows: 2015 2014 2013 (In Thousands) Charged to utility operating expenses: Current income taxes: Federal $ 18,661 $ 944 $ 53,937 State 5,758 110 15,191 Total current income taxes 24,419 1,054 69,128 Deferred income taxes: Federal 29,165 58,114 (8,048 ) State 5,019 12,498 (1,031 ) Total deferred income taxes 34,184 70,612 (9,079 ) Net amortization of investment credit (1,319 ) (1,431 ) (1,501 ) Total charge to utility operating expenses 57,284 70,235 58,548 Charged to other income and deductions: Current income taxes: Federal (1,715 ) 329 (752 ) State (240 ) 69 (62 ) Total current income taxes (1,955 ) 398 (814 ) Deferred income taxes: Federal 740 (1,202 ) (13 ) State 150 (148 ) (1 ) Total deferred income taxes 890 (1,350 ) (14 ) Net provision to other income and deductions (1,065 ) (952 ) (828 ) Total federal and state income tax provisions $ 56,219 $ 69,283 $ 57,720
Schedule Of Effective Income Tax Rate	The reasons for the difference, stated as a percentage of pretax income, are as follows: 2015 2014 2013 Federal statutory tax rate 35.0 % 35.0 % 35.0 % State income tax, net of federal tax benefit 4.4 % 4.6 % 6.0 % Amortization of investment tax credits (0.8 )% (0.8 )% (1.0 )% Depreciation flow through and amortization (0.2 )% (0.2 )% (0.2 )% Additional funds used during construction - equity (1.9 )% (0.2 )% 0.4 % Manufacturers’ Production Deduction (Sec. 199) (1.0 )% — % (3.2 )% Other – net 0.1 % 0.4 % 0.4 % Effective tax rate 35.6 % 38.8 % 37.4 %
Schedule Of Deferred Tax Assets And Liabilities	The significant items comprising IPL’s net accumulated deferred tax liability recognized on the audited Consolidated Balance Sheets as of December 31, 2015 and 2014 , are as follows: 2015 2014 (In Thousands) Deferred tax liabilities: Relating to utility property, net $ 541,369 $ 539,318 Regulatory assets recoverable through future rates 178,187 161,697 Other 11,349 13,885 Total deferred tax liabilities 730,905 714,900 Deferred tax assets: Investment tax credit 1,507 2,019 Regulatory liabilities including ARO 260,555 247,118 Employee benefit plans 38,159 45,090 Net operating loss — 31,172 Other 10,953 10,008 Total deferred tax assets 311,174 335,407 Net deferred tax liability 419,731 379,493 Less: deferred tax asset - current — (41,551 ) Deferred income taxes – net $ 419,731 $ 421,044
Reconciliation Of Unrecognized Tax Benefits	The following is a reconciliation of the beginning and ending amounts of unrecognized tax benefits for the years ended December 31, 2015 , 2014 and 2013 : 2015 2014 2013 (In Thousands) Unrecognized tax benefits at January 1 $ 7,042 $ 6,734 $ 6,138 Gross increases – current period tax positions 962 975 986 Gross decreases – prior period tax positions (857 ) (667 ) (390 ) Unrecognized tax benefits at December 31 $ 7,147 $ 7,042 $ 6,734

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Entity Information [Line Items]
Schedule Of Defined Benefit Plans Disclosures	The following table presents information relating to the Pension Plans: Pension benefits 2015 2014 (In Thousands) Change in benefit obligation: Projected benefit obligation at January 1 $ 748,421 $ 650,713 Service cost 8,314 7,231 Interest cost 29,638 31,154 Actuarial (gain) loss (31,989 ) 90,693 Amendments (primarily increases in pension bands) 5,409 1,233 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Projected benefit obligation at December 31 723,887 748,421 Change in plan assets: Fair value of plan assets at January 1 657,239 561,586 Actual return on plan assets 1,074 74,147 Employer contributions 25,166 54,109 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Fair value of plan assets at December 31 647,573 657,239 Unfunded status $ (76,314 ) $ (91,182 ) Amounts recognized in the statement of financial position: Noncurrent liabilities $ (76,314 ) $ (91,182 ) Net amount recognized at end of year $ (76,314 ) $ (91,182 ) Sources of change in regulatory assets (1) : Prior service cost arising during period $ 5,409 $ 1,233 Net loss arising during period 11,757 58,439 Amortization of prior service cost (4,867 ) (4,853 ) Amortization of loss (14,096 ) (9,710 ) Total recognized in regulatory assets (1) $ (1,797 ) $ 45,109 Amounts included in regulatory assets (1) : Net loss $ 209,252 $ 211,592 Prior service cost 25,842 25,299 Total amounts included in regulatory assets $ 235,094 $ 236,891 (1) Represents amounts included in regulatory assets yet to be recognized as components of net prepaid (accrued) benefit costs.
Information For Pension Plans With A Benefit Obligation In Excess Of Plan Assets	Pension benefits 2015 2014 (In Thousands) Benefit obligation $ 723,887 $ 748,421 Plan assets 647,573 657,239 Benefit obligation in excess of plan assets $ 76,314 $ 91,182
Information For Pension Plans With An Accumulated Benefit Obligation In Excess Of Plan Assets	Pension benefits 2015 2014 (In Thousands) Accumulated benefit obligation $ 712,297 $ 734,328 Plan assets 647,573 657,239 Accumulated benefit obligation in excess of plan assets $ 64,724 $ 77,089
Schedule Of Net Periodic Benefit Costs	Pension benefits for 2015 2014 2013 (In Thousands) Components of net periodic benefit cost: Service cost $ 8,314 $ 7,231 $ 9,195 Interest cost 29,638 31,154 28,363 Expected return on plan assets (1) (44,819 ) (41,893 ) (38,287 ) Amortization of prior service cost 4,867 4,853 4,916 Recognized actuarial loss 13,890 9,710 22,735 Recognized settlement loss 206 — — — Total pension cost 12,096 11,055 26,922 Less: amounts capitalized 1,403 1,426 2,881 Amount charged to expense $ 10,693 $ 9,629 $ 24,041 Rates relevant to each year’s expense calculations: Discount rate – defined benefit pension plan 4.06 % 4.92 % 3.80 % Discount rate – supplemental retirement plan 3.82 % 4.64 % 3.41 % Expected return on defined benefit pension plan assets 6.75 % 7.00 % 7.25 % Expected return on supplemental retirement plan assets 6.75 % 7.00 % 7.25 % (1) For purposes of calculating the expected return on pension plan assets under GAAP, the market-related value of assets (MRVA) is used. GAAP requires that the difference between actual plan asset returns and estimated plan asset returns be amortized into the MRVA equally over a period not to exceed five years. We use a methodology under which we include the difference between actual and estimated asset returns in the MRVA equally over a three year period. The MRVA used in the calculation of expected return on pension plan assets was approximately $643.0 million in 2015, $652.2 million in 2014, and $556.4 million in 2013.
Schedule Of Asset Allocation Guidelines	The following table summarizes the Company’s target pension plan allocation for 2015 : Asset Category: Target Allocations Equity Securities 60% Debt Securities 40%
Schedule Of Fair Value Of Pension Plan Assets	Fair Value Measurements at December 31, 2015 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 176 $ 176 $ — — % Mutual funds: U.S. equities 318,368 318,368 — 49 % International equities 60,751 60,751 — 10 % Fixed income 215,325 215,325 — 33 % Fixed income securities: U.S. Treasury securities 52,953 52,953 — 8 % Total $ 647,573 $ 647,573 $ — 100 % Fair Value Measurements at December 31, 2014 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 2,575 $ 2,575 $ — — % Mutual funds: U.S. equities 325,370 325,370 — 50 % International equities 56,662 56,662 — 9 % Fixed income 205,409 205,409 — 31 % Fixed income securities: U.S. Treasury securities 66,913 66,913 — 10 % Hedge funds 310 — 310 — % Total $ 657,239 $ 656,929 $ 310 100 %
Schedule Of Expected Benefit Payments	Expected benefit payments are expected to be paid out of the Pension Plans as follows: Year Pension Benefits (In Thousands) 2016 $ 38,289 2017 39,909 2018 41,213 2019 42,638 2020 43,920 2021 through 2025 233,449
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Schedule Of Defined Benefit Plans Disclosures	Pension benefits 2015 2014 (In Thousands) Change in benefit obligation: Projected benefit obligation at January 1 $ 748,421 $ 650,713 Service cost 8,314 7,231 Interest cost 29,638 31,154 Actuarial (gain) loss (31,989 ) 90,693 Amendments (primarily increases in pension bands) 5,409 1,233 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Projected benefit obligation at December 31 723,887 748,421 Change in plan assets: Fair value of plan assets at January 1 657,239 561,586 Actual return on plan assets 1,074 74,147 Employer contributions 25,166 54,109 Settlements (395 ) — Benefits paid (35,511 ) (32,603 ) Fair value of plan assets at December 31 647,573 657,239 Unfunded status $ (76,314 ) $ (91,182 ) Amounts recognized in the statement of financial position: Noncurrent liabilities $ (76,314 ) $ (91,182 ) Net amount recognized at end of year $ (76,314 ) $ (91,182 ) Sources of change in regulatory assets (1) : Prior service cost arising during period $ 5,409 $ 1,233 Net loss arising during period 11,757 58,439 Amortization of prior service cost (4,867 ) (4,853 ) Amortization of loss (14,096 ) (9,710 ) Total recognized in regulatory assets (1) $ (1,797 ) $ 45,109 Amounts included in regulatory assets (1) : Net loss $ 209,252 $ 211,592 Prior service cost 25,842 25,299 Total amounts included in regulatory assets $ 235,094 $ 236,891 (1) Represents amounts included in regulatory assets yet to be recognized as components of net prepaid (accrued) benefit costs.
Information For Pension Plans With A Benefit Obligation In Excess Of Plan Assets	Pension benefits 2015 2014 (In Thousands) Benefit obligation $ 723,887 $ 748,421 Plan assets 647,573 657,239 Benefit obligation in excess of plan assets $ 76,314 $ 91,182
Information For Pension Plans With An Accumulated Benefit Obligation In Excess Of Plan Assets	Pension benefits 2015 2014 (In Thousands) Accumulated benefit obligation $ 712,297 $ 734,328 Plan assets 647,573 657,239 Accumulated benefit obligation in excess of plan assets $ 64,724 $ 77,089
Schedule Of Net Periodic Benefit Costs	Pension benefits for 2015 2014 2013 (In Thousands) Components of net periodic benefit cost: Service cost $ 8,314 $ 7,231 $ 9,195 Interest cost 29,638 31,154 28,363 Expected return on plan assets (1) (44,819 ) (41,893 ) (38,287 ) Amortization of prior service cost 4,867 4,853 4,916 Recognized actuarial loss 13,890 9,710 22,735 Recognized settlement loss 206 — — Total pension cost 12,096 11,055 26,922 Less: amounts capitalized 1,403 1,426 2,881 Amount charged to expense $ 10,693 $ 9,629 $ 24,041 Rates relevant to each year’s expense calculations: Discount rate – defined benefit pension plan 4.06 % 4.92 % 3.80 % Discount rate – supplemental retirement plan 3.82 % 4.64 % 3.41 % Expected return on defined benefit pension plan assets 6.75 % 7.00 % 7.25 % Expected return on supplemental retirement plan assets 6.75 % 7.00 % 7.25 % (1) For purposes of calculating the expected return on pension plan assets under GAAP, the market-related value of assets (MRVA) is used. GAAP requires that the difference between actual plan asset returns and estimated plan asset returns be amortized into the MRVA equally over a period not to exceed five years. We use a methodology under which we include the difference between actual and estimated asset returns in the MRVA equally over a three year period. The MRVA used in the calculation of expected return on pension plan assets was approximately $643.0 million in 2015, $652.2 million in 2014, and $556.4 million in 2013.
Schedule Of Asset Allocation Guidelines	Asset Category: Target Allocations Equity Securities 60% Debt Securities 40%
Schedule Of Fair Value Of Pension Plan Assets	Fair Value Measurements at December 31, 2015 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 176 $ 176 $ — — % Mutual funds: U.S. equities 318,368 318,368 — 49 % International equities 60,751 60,751 — 10 % Fixed income 215,325 215,325 — 33 % Fixed income securities: U.S. Treasury securities 52,953 52,953 — 8 % Total $ 647,573 $ 647,573 $ — 100 % Fair Value Measurements at December 31, 2014 (in thousands) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Asset Category Total (Level 1) (Level 2) % Short-term investments $ 2,575 $ 2,575 $ — — % Mutual funds: U.S. equities 325,370 325,370 — 50 % International equities 56,662 56,662 — 9 % Fixed income 205,409 205,409 — 31 % Fixed income securities: U.S. Treasury securities 66,913 66,913 — 10 % Hedge funds 310 — 310 — % Total $ 657,239 $ 656,929 $ 310 100 %
Schedule Of Expected Benefit Payments	Year Pension Benefits (In Thousands) 2016 $ 38,289 2017 39,909 2018 41,213 2019 42,638 2020 43,920 2021 through 2025 233,449

Business Segment Information (T

Business Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Summary Of Company's Reporting Segments	The following table provides information about IPALCO’s business segments (in millions): 2015 2014 2013 Utility All Other Total Utility All Other Total Utility All Other Total Operating revenues $ 1,250 — $ 1,250 $ 1,322 — $ 1,322 $ 1,256 — $ 1,256 Depreciation and amortization 188 — 188 185 — 185 182 — 182 Income taxes 56 (25 ) 32 69 (21 ) 48 58 (20 ) 38 Net income 102 (42 ) 60 110 (32 ) 78 97 (33 ) 64 Utility plant - net of depreciation 3,451 — 3,451 2,857 — 2,857 2,553 — 2,553 Capital expenditures 686 — 686 382 — 382 242 — 242

Overview and Summary of Signi32

Overview and Summary of Significant Accounting Policies (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)customersegmentitemgenerating_stationmiMW	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Significant Accounting Policies [Line Items]
Service cost			$ 8,314,000	$ 7,231,000	$ 9,195,000
Interest cost			$ 29,638,000	31,154,000	28,363,000
Ownership interest in IPALCO by AES U.S. Investments (percent)			88.40%
Ownership interest in IPALCO by CDPQ (percent)			11.60%
Number of customers | customer			480,000
Distance of Furthest Customer from Indianapolis | mi			40
Number of generating stations | generating_station			4
Electric generation capability for winter, megawatts | MW			3,259
Electric generation capability for summer, megawatts | MW			3,141
Total other assets			$ 6,181,000	6,743,000
Unbilled energy revenues			42,100,000	48,400,000
Operating revenues			1,250,399,000	1,321,674,000	1,255,734,000
Provision for doubtful accounts			4,300,000	4,900,000	$ 3,800,000
Loss contingencies accrued			$ 5,600,000	$ 5,200,000
Number of suppliers | item			4
Capitalized amount, rate			8.10%	8.30%	8.60%
Depreciation rate			4.20%	4.10%	4.00%
Depreciation expense			$ 198,800,000	$ 185,900,000	$ 180,000,000
Utility plant assets			$ 3,451,383,000	2,856,634,000	2,553,000,000
Number of segments | segment			2
Outstanding receivables purchased amount			$ 0	50,000,000
Deferred financing costs that will be reclassified and deducted from debt amount			$ 300,000
Labor Force Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration risk percentage			65.00%
Supplier Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration risk percentage			53.00%
AES U.S. Holdings, LLC [Member]
Significant Accounting Policies [Line Items]
Ownership Interest in Parent Company, Percent			85.00%
CDPQ [Member]
Significant Accounting Policies [Line Items]
Ownership interest in IPALCO by AES U.S. Investments (percent)	11.60%
Ownership Interest in Parent Company, Percent			15.00%
Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Service cost			$ 8,314,000	7,231,000	9,195,000
Interest cost			$ 29,638,000	31,154,000	28,363,000
Number of customers | customer			480,000
Distance of Furthest Customer from Indianapolis | mi			40
Electric generation capability for winter, megawatts | MW			3,259
Electric generation capability for summer, megawatts | MW			3,141
Total other assets			$ 947,000	1,648,000
Unbilled energy revenues			42,100,000	48,400,000
Operating revenues			1,250,399,000	1,321,674,000	1,255,734,000
Provision for doubtful accounts			4,300,000	4,900,000	$ 3,800,000
Loss contingencies accrued			$ 5,600,000	$ 5,200,000
Number of suppliers | item			4
Capitalized amount, rate			8.10%	8.30%	8.60%
Depreciation rate			4.20%	4.10%	4.00%
Depreciation expense			$ 198,800,000	$ 185,900,000	$ 180,000,000
Interest or penalties				0	$ 0
Utility plant assets			3,451,383,000	2,856,634,000
Outstanding receivables purchased amount			0	$ 50,000,000
Deferred financing costs that will be reclassified and deducted from debt amount			$ 300,000
Indianapolis Power And Light Company [Member] | Eagle Valley CCGT And Harding Street Refueling Project [Member]
Significant Accounting Policies [Line Items]
Capitalized amount, rate			7.30%	7.60%
Indianapolis Power And Light Company [Member] | Labor Force Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration risk percentage			65.00%
Indianapolis Power And Light Company [Member] | Supplier Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration risk percentage			53.00%
Physical Unit [Member]
Significant Accounting Policies [Line Items]
Collective bargaining agreement expiration date			Dec. 10, 2018
Physical Unit [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Collective bargaining agreement expiration date			Dec. 10, 2018
Clerical-Technical Unit [Member]
Significant Accounting Policies [Line Items]
Collective bargaining agreement expiration date			Feb. 20, 2017
Clerical-Technical Unit [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Collective bargaining agreement expiration date			Feb. 20, 2017
Adjustments for New Accounting Principle, Early Adoption [Member]
Significant Accounting Policies [Line Items]
Total other assets			$ (20,800,000)
Adjustments for New Accounting Principle, Early Adoption [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Total other assets			(13,900,000)
Scenario, Forecast [Member]
Significant Accounting Policies [Line Items]
Service cost		$ 400,000
Interest cost		5,300,000
Scenario, Forecast [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Service cost		400,000
Interest cost		5,300,000
Scenario, Forecast [Member] | Pension Plan [Member]
Significant Accounting Policies [Line Items]
Service cost		400,000
Interest cost		5,300,000
Scenario, Forecast [Member] | Pension Plan [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Service cost		400,000
Interest cost		5,300,000
Disaggregated Rate Approach [Member] | Scenario, Forecast [Member] | Pension Plan [Member]
Significant Accounting Policies [Line Items]
Service cost		7,018,000
Interest cost		25,634,000
Disaggregated Rate Approach [Member] | Scenario, Forecast [Member] | Pension Plan [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Service cost		7,018,000
Interest cost		25,634,000
Aggregate Rate Approach [Member] | Scenario, Forecast [Member] | Pension Plan [Member]
Significant Accounting Policies [Line Items]
Service cost		7,382,000
Interest cost		30,916,000
Aggregate Rate Approach [Member] | Scenario, Forecast [Member] | Pension Plan [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Service cost		7,382,000
Interest cost		30,916,000
Impact of Change [Member] | Scenario, Forecast [Member] | Pension Plan [Member]
Significant Accounting Policies [Line Items]
Service cost		(364,000)
Interest cost		(5,282,000)
Impact of Change [Member] | Scenario, Forecast [Member] | Pension Plan [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Service cost		(364,000)
Interest cost		$ (5,282,000)
Maximum [Member] | Indianapolis Power And Light Company [Member]
Significant Accounting Policies [Line Items]
Outstanding receivables purchased amount			$ 50,000,000

Regulatory Matters (Details)

Regulatory Matters (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016MW	Dec. 31, 2015USD ($)MW	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Regulatory Matters [Line Items]
Increase in basic rates and charges		$ 63,300
Increase in basic rates and charges, percentage		5.30%
Equipment recovery approved amount		$ 978,000
Revenue requirement to be included in rate		82,000
CCT expenditures		252,200	$ 176,300	$ 126,600
Costs allocated to Company for projects of other transmission system owner members		12,100
Regulatory assets		448,200	419,193
Deferred Transmission Expansion Costs [Member]
Regulatory Matters [Line Items]
Regulatory assets		19,700
Indianapolis Power And Light Company [Member]
Regulatory Matters [Line Items]
Increase in basic rates and charges		$ 63,300
Increase in basic rates and charges, percentage		5.30%
Equipment recovery approved amount		$ 978,000
Revenue requirement to be included in rate		82,000
CCT expenditures		252,200	176,300	$ 126,600
Costs allocated to Company for projects of other transmission system owner members		12,100
Regulatory assets		448,200	$ 419,193
Indianapolis Power And Light Company [Member] | Deferred Transmission Expansion Costs [Member]
Regulatory Matters [Line Items]
Regulatory assets		$ 19,700
Indianapolis Power And Light Company [Member] | Indiana [Member]
Regulatory Matters [Line Items]
Amount of electricity required to be purchased under purchase power agreement | MW		100
Indianapolis Power And Light Company [Member] | Minnesota [Member]
Regulatory Matters [Line Items]
Amount of electricity required to be purchased under purchase power agreement | MW		200
Length power purchase agreement		20 years
Indianapolis Power And Light Company [Member] | Solar Generated Electricity [Member]
Regulatory Matters [Line Items]
Amount of electricity required to be purchased under purchase power agreement | MW		95
Subsequent Event [Member] | Indianapolis Power And Light Company [Member] | Solar Generated Electricity [Member]
Regulatory Matters [Line Items]
Amount of electricity required to be purchased under purchase power agreement | MW	97

Utility Plant In Service (Narra

Utility Plant In Service (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Public Utility, Property, Plant and Equipment [Line Items]
Direct first mortgage lien	$ 1,283.5
Non-contractually required removal costs of utility plant in service	673.8	$ 636.8
Contractually required removal costs of utility plant in service	59	59.1
Indianapolis Power And Light Company [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Direct first mortgage lien	1,283.5
Non-contractually required removal costs of utility plant in service	673.8	636.8
Contractually required removal costs of utility plant in service	$ 59	$ 59.1

Utility Plant In Service (Sched

Utility Plant In Service (Schedule Of Original Cost Of Utility Plant In Service) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Entity Information [Line Items]
Production	$ 3,111,674	$ 2,862,579
Transmission	293,767	268,594
Distribution	1,371,029	1,323,190
General plant	216,124	203,660
Total utility plant in service	4,992,594	4,658,023
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Production	3,111,674	2,862,579
Transmission	293,767	268,594
Distribution	1,371,029	1,323,190
General plant	216,124	203,660
Total utility plant in service	$ 4,992,594	$ 4,658,023

Utility Plant In Service - ARO

Utility Plant In Service - ARO (Reconciliation of Asset Retirement Obligation Liability) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of January 1	$ 59.1	$ 41.4
Liabilities incurred	0.6	0
Liabilities settled	(2.5)	0
Revisions in estimated cash flows	(1.3)	15.4
Accretion expense	3.1	2.3
Balance as of December 31	59	59.1
Indianapolis Power And Light Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of January 1	59.1	41.4
Liabilities incurred	0.6	0
Liabilities settled	(2.5)	0
Revisions in estimated cash flows	(1.3)	15.4
Accretion expense	3.1	2.3
Balance as of December 31	$ 59	$ 59.1

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Entity Information [Line Items]
Unamortized debt discount	$ (4,600)	$ (4,300)
Asset retirement obligations	58,986	59,098
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Unamortized debt discount	(4,242)	(2,940)
Asset retirement obligations	$ 58,986	$ 59,098

Fair Value (Summary Of Fair Val

Fair Value (Summary Of Fair Value Assets And Liabilities Measured On A Recurring Basis, Level 3) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Entity Information [Line Items]
Financial transmission rights	$ 4,150	$ 6,235
Total financial assets measured at fair value	4,150	6,235
Other derivative liabilities	121	140
Total financial liabilities measured at fair value	121	140
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Financial transmission rights	4,150	6,235
Total financial assets measured at fair value	4,150	6,235
Other derivative liabilities	121	140
Total financial liabilities measured at fair value	121	140
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Entity Information [Line Items]
Financial transmission rights	0	0
Total financial assets measured at fair value	0	0
Other derivative liabilities	0	0
Total financial liabilities measured at fair value	0	0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Financial transmission rights	0	0
Total financial assets measured at fair value	0	0
Other derivative liabilities	0	0
Total financial liabilities measured at fair value	0	0
Significant Observable Inputs (Level 2) [Member]
Entity Information [Line Items]
Financial transmission rights	0	0
Total financial assets measured at fair value	0	0
Other derivative liabilities	0	0
Total financial liabilities measured at fair value	0	0
Significant Observable Inputs (Level 2) [Member] | Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Financial transmission rights	0	0
Total financial assets measured at fair value	0	0
Other derivative liabilities	0	0
Total financial liabilities measured at fair value	0	0
Unobservable Inputs (Level 3) [Member]
Entity Information [Line Items]
Financial transmission rights	4,150	6,235
Total financial assets measured at fair value	4,150	6,235
Other derivative liabilities	121	140
Total financial liabilities measured at fair value	121	140
Unobservable Inputs (Level 3) [Member] | Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Financial transmission rights	4,150	6,235
Total financial assets measured at fair value	4,150	6,235
Other derivative liabilities	121	140
Total financial liabilities measured at fair value	$ 121	$ 140

Fair Value (Reconciliation Of F

Fair Value (Reconciliation Of Financial Instruments Classified As Level 3) (Details) - Derivative Financial Instruments, net Liabilities [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 6,095	$ 4,133
Unrealized gain recognized in earnings		16
Unrealized gain recognized in earnings	47
Issuances	13,281	15,710
Settlements	(15,394)	(13,764)
Ending balance	$ 4,029	$ 6,095

Fair Value (Schedule Of Face An

Fair Value (Schedule Of Face And Fair Value Of Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Face Value	$ 2,345.3	$ 2,005.3
Fair Value	2,482.2	2,281.2
Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Face Value	1,540.3	1,205.3
Fair Value	1,663.7	1,436.2
Fixed Rate [Member]
Debt Instrument [Line Items]
Face Value	2,088.4	1,955.3
Fair Value	2,225.3	2,231.2
Fixed Rate [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Face Value	1,283.4	1,155.3
Fair Value	1,406.8	1,386.2
Variable Rate [Member]
Debt Instrument [Line Items]
Face Value	256.9	50
Fair Value	256.9	50
Variable Rate [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Face Value	256.9	50
Fair Value	$ 256.9	$ 50

Regulatory Assets And Liabili41

Regulatory Assets And Liabilities (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	$ 28,169	$ 27,943
Regulatory assets, current	8,002	93
Increase (decrease) in deferred fuel liability	1,900
Deferred Fuel Over/Under-Collection [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	19,746	17,837
Indianapolis Power And Light Company [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	28,169	27,943
Regulatory assets, current	8,002	93
Increase (decrease) in deferred fuel liability	1,900
Indianapolis Power And Light Company [Member] | Deferred Fuel Over/Under-Collection [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	$ 19,746	$ 17,837
Minimum [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period of regulatory assets	1 year
Minimum [Member] | Indianapolis Power And Light Company [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period of regulatory assets	1 year
Maximum [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period of regulatory assets	35 years
Maximum [Member] | Indianapolis Power And Light Company [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period of regulatory assets	35 years

Regulatory Assets And Liabili42

Regulatory Assets And Liabilities (Schedule Of Regulatory Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, current	$ 8,002	$ 93
Regulatory assets, noncurrent	448,200	419,193
Total regulatory assets	456,202	419,286
Regulatory liabilities, current	28,169	27,943
Regulatory liabilities, noncurrent	639,516	610,917
Total regulatory liabilities	667,685	638,860
Deferred Fuel Over/Under-Collection [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	19,746	17,837
Financial Transmission Rights [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	4,150	6,235
DSM Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	4,273	2,001
Environmental Projects [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	0	1,870
Asset Retirement Obligation Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, noncurrent	637,065	607,628
Unamortized Investment Tax Credit [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, noncurrent	2,451	3,289
Environmental Projects [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, current	8,002	93
Unrecognized Pension And Other Post Retirement Benefit Plan Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	226,889	229,590
Income Taxes Recoverable From Customers [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	35,765	31,335
Deferred MISO Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	128,610	110,500
Unamortized Petersburg Unit 4 Carrying Charges And Certain Other Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	11,248	12,302
Unamortized Reacquisition Premium On Debt [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	23,268	24,585
Environmental Projects [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	16,876	7,671
Other Miscellaneous [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	5,544	3,210
Indianapolis Power And Light Company [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, current	8,002	93
Regulatory assets, noncurrent	448,200	419,193
Total regulatory assets	456,202	419,286
Regulatory liabilities, current	28,169	27,943
Regulatory liabilities, noncurrent	639,516	610,917
Total regulatory liabilities	667,685	638,860
Indianapolis Power And Light Company [Member] | Deferred Fuel Over/Under-Collection [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	19,746	17,837
Indianapolis Power And Light Company [Member] | Financial Transmission Rights [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	4,150	6,235
Indianapolis Power And Light Company [Member] | DSM Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	4,273	2,001
Indianapolis Power And Light Company [Member] | Environmental Projects [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, current	0	1,870
Indianapolis Power And Light Company [Member] | Asset Retirement Obligation Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, noncurrent	637,065	607,628
Indianapolis Power And Light Company [Member] | Unamortized Investment Tax Credit [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory liabilities, noncurrent	2,451	3,289
Indianapolis Power And Light Company [Member] | Environmental Projects [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, current	8,002	93
Indianapolis Power And Light Company [Member] | Unrecognized Pension And Other Post Retirement Benefit Plan Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	226,889	229,590
Indianapolis Power And Light Company [Member] | Income Taxes Recoverable From Customers [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	35,765	31,335
Indianapolis Power And Light Company [Member] | Deferred MISO Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	128,610	110,500
Indianapolis Power And Light Company [Member] | Unamortized Petersburg Unit 4 Carrying Charges And Certain Other Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	11,248	12,302
Indianapolis Power And Light Company [Member] | Unamortized Reacquisition Premium On Debt [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	23,268	24,585
Indianapolis Power And Light Company [Member] | Environmental Projects [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	16,876	7,671
Indianapolis Power And Light Company [Member] | Other Miscellaneous [Member]
Regulatory Assets And Liabilities [Line Items]
Regulatory assets, noncurrent	$ 5,544	$ 3,210

Equity (Narrative) (Details)

Equity (Narrative) (Details) $ in Thousands	Apr. 01, 2015USD ($)shares	Feb. 11, 2015USD ($)itemshares	Jun. 27, 2014USD ($)	Jul. 31, 2013USD ($)	Jun. 30, 2015	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)shares
Class of Stock [Line Items]
Common shares issued		100
Additional Investment through Agreement, Contributed through Period End | $						$ 214,400
Ownership percentage by parent						88.40%
Equity contributions from AES | $						$ 0	$ 106,400	$ 49,091
Common stock issued and sold to CDPQ | $						$ 214,366
Debt to capitalization ratio						0.65
Preferred stock outstanding						591,353
Change in capital stock						0	0	0
5.65% Series Preferred Stock [Member]
Class of Stock [Line Items]
Dividend rate on preferred stock						5.65%
Preferred stock issued						500,000
Preferred stock outstanding						500,000
Nonredeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock outstanding						91,353
AES U.S. Investments [Member]
Class of Stock [Line Items]
Ownership percentage by parent		85.00%
Number of board members | item		9
Ipalco Enterprises, Inc. [Member]
Class of Stock [Line Items]
Additional investment through agreement | $		$ 349,000
Increase in ownership percentage after investment		17.65%
Direct and indirect ownership percentage		30.00%
Ownership percentage by parent		82.35%
Number of board members | item		11
Equity contributions from AES | $			$ 106,400	$ 49,100		$ 0	$ 106,400	$ 49,091
Common stock issued and sold to CDPQ | $						214,366
CDPQ [Member]
Class of Stock [Line Items]
Ownership percentage by parent					11.60%
Number of board members | item		2
Minimum ownership percentage to retain board members		5.00%
Percentage Of Direct And Indirect Ownership Share Of IPALCO	24.90%
Indianapolis Power And Light Company [Member]
Class of Stock [Line Items]
Equity contributions from AES | $			$ 106,400	$ 49,100		$ 214,364	106,400	49,091
Debt to capitalization ratio						0.65
Total preferred stock dividends declared | $						$ 3,213	$ 3,213	$ 3,213
Preferred stock outstanding						591,353
Change in capital stock						0	0	0
Indianapolis Power And Light Company [Member] | 5.65% Series Preferred Stock [Member]
Class of Stock [Line Items]
Dividend rate on preferred stock						5.65%
Preferred stock issued						500,000
Preferred stock outstanding						500,000
Indianapolis Power And Light Company [Member] | Nonredeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock outstanding						91,353
Minimum [Member]
Class of Stock [Line Items]
Dividend rate on preferred stock						4.00%
Minimum [Member] | Indianapolis Power And Light Company [Member]
Class of Stock [Line Items]
Dividend rate on preferred stock						4.00%
Maximum [Member]
Class of Stock [Line Items]
Dividend rate on preferred stock						5.65%
Maximum [Member] | Indianapolis Power And Light Company [Member]
Class of Stock [Line Items]
Dividend rate on preferred stock						5.65%
Common Stock [Member]
Class of Stock [Line Items]
Common stock issued and sold to CDPQ (shares)	11,818,828
Common stock issued and sold to CDPQ | $	$ 214,400
Common Stock [Member] | Ipalco Enterprises, Inc. [Member]
Class of Stock [Line Items]
Common stock issued and sold to CDPQ (shares)	11,818,828
Common stock issued and sold to CDPQ | $	$ 214,400

Equity (Summary Of Preferred St

Equity (Summary Of Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Shares Outstanding	591,353
Par value, plus premium, if applicable	$ 59,784	$ 59,784	$ 59,784
Preferred stock par value	$ 100
Preferred stock authorized	2,000,000
4% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	47,611
Call Price	$ 118
Par value, plus premium, if applicable	$ 5,410	5,410	5,410
Dividend rate on preferred stock	4.00%
4.2% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	19,331
Call Price	$ 103
Par value, plus premium, if applicable	$ 1,933	1,933	1,933
Dividend rate on preferred stock	4.20%
4.6% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	2,481
Call Price	$ 103
Par value, plus premium, if applicable	$ 248	248	248
Dividend rate on preferred stock	4.60%
4.8% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	21,930
Call Price	$ 101
Par value, plus premium, if applicable	$ 2,193	2,193	2,193
Dividend rate on preferred stock	4.80%
5.65% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	500,000
Call Price	$ 100
Par value, plus premium, if applicable	$ 50,000	50,000	50,000
Dividend rate on preferred stock	5.65%
Indianapolis Power And Light Company [Member]
Class of Stock [Line Items]
Shares Outstanding	591,353
Par value, plus premium, if applicable	$ 59,784	59,784	59,784
Preferred stock par value	$ 100
Preferred stock authorized	2,000,000
Indianapolis Power And Light Company [Member] | 4% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	47,611
Call Price	$ 118
Par value, plus premium, if applicable	$ 5,410	5,410	5,410
Dividend rate on preferred stock	4.00%
Indianapolis Power And Light Company [Member] | 4.2% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	19,331
Call Price	$ 103
Par value, plus premium, if applicable	$ 1,933	1,933	1,933
Dividend rate on preferred stock	4.20%
Indianapolis Power And Light Company [Member] | 4.6% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	2,481
Call Price	$ 103
Par value, plus premium, if applicable	$ 248	248	248
Dividend rate on preferred stock	4.60%
Indianapolis Power And Light Company [Member] | 4.8% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	21,930
Call Price	$ 101
Par value, plus premium, if applicable	$ 2,193	2,193	2,193
Dividend rate on preferred stock	4.80%
Indianapolis Power And Light Company [Member] | 5.65% Series Preferred Stock [Member]
Class of Stock [Line Items]
Shares Outstanding	500,000
Call Price	$ 100
Par value, plus premium, if applicable	$ 50,000	$ 50,000	$ 50,000
Dividend rate on preferred stock	5.65%

Debt (Narrative) (Details)

Debt (Narrative) (Details)	Oct. 19, 2015USD ($)	Oct. 16, 2015USD ($)	Dec. 31, 2015USD ($)note_series	Oct. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	May. 31, 2014USD ($)	Jun. 30, 2013USD ($)	Dec. 31, 2015USD ($)note_series	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Debt Instrument [Line Items]
Secured debt gross			$ 2,178,450,000							$ 2,178,450,000
Aggregate principal amount			2,345,300,000							2,345,300,000	$ 2,005,300,000
Net proceeds from debt issuance										753,350,000	128,358,000	$ 169,728,000
Line of credit facility, term								5 years
Long-term debt			2,173,837,000							2,173,837,000	1,951,013,000
Charges related to early extinguishment of debt										21,956,000	0	35,000
Maximum borrowing capacity			500,000,000					$ 250,000,000		500,000,000
Long-term Line of Credit											0
Maximum amount of short-term indebtedness outstanding										500,000,000
Authorized amount of debt to be issued			650,000,000							650,000,000
Authorized amount of debt to be refinanced			196,500,000							196,500,000
Preferred Stock Issuable in Lieu of Portion of Maximum Authorized Amount of Debt			65,000,000							65,000,000
Outstanding receivables purchased amount			0							0	50,000,000
Total fees paid to Purchasers										$ 400,000	400,000
Net Earnings to Annual Interest Requirement Ratio										2.5
Letter of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, accordion feature								$ 150,000,000
Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Secured debt gross			1,373,450,000							$ 1,373,450,000
Aggregate principal amount			1,540,300,000							1,540,300,000	1,205,300,000
Net proceeds from debt issuance										348,638,000	128,358,000	169,728,000
Line of credit facility, term								5 years
Long-term debt			1,369,208,000							1,369,208,000	1,152,360,000
Maximum borrowing capacity			500,000,000					$ 250,000,000		500,000,000
Long-term Line of Credit			0							0
Maximum amount of short-term indebtedness outstanding										500,000,000
Authorized amount of debt to be issued			650,000,000							650,000,000
Authorized amount of debt to be refinanced			196,500,000							196,500,000
Preferred Stock Issuable in Lieu of Portion of Maximum Authorized Amount of Debt			65,000,000							65,000,000
Outstanding receivables purchased amount			0							0	50,000,000
First mortgage bonds			1,279,208,000							$ 1,279,208,000	1,152,360,000
Net Earnings to Annual Interest Requirement Ratio										2.5
Indianapolis Power And Light Company [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, accordion feature								$ 150,000,000
Ipalco Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Net proceeds from debt issuance										$ 404,712,000	0	0
Early tender premium										(21,956,000)	0	(377,000)
Long-term debt			$ 804,629,000							804,629,000	798,653,000
Charges related to early extinguishment of debt										$ 21,956,000	0	$ 0
First Mortgage Bond 4.90% Due January 2016 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate			4.90%							4.90%
Debt instrument, maturity date										Jan. 1, 2016
First mortgage bonds			$ 0							$ 0	30,000,000
First Mortgage Bond 4.90% Due January 2016 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate			4.90%							4.90%
Refunded aggregate principal			$ 41,900,000
Debt instrument, maturity date										Jan. 1, 2016
First mortgage bonds			$ 0							$ 0	41,850,000
First Mortgage Bond 4.90% Due January 2016 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate			4.90%							4.90%
Debt instrument, maturity date										Jan. 1, 2016
First mortgage bonds			$ 0							$ 0	60,000,000
First Mortgage Bonds [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Secured debt gross			$ 1,283,500,000							$ 1,283,500,000
First Mortgage Bonds Due January 2016 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate			4.90%							4.90%
Refunded aggregate principal			$ 131,900,000
Environmental Facilities Refunding Revenue Notes, Series 2015A [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date										Dec. 1, 2020
Environmental Facilities Refunding Revenue Notes, Series 2015B [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date										Dec. 1, 2020
3.45% Senior Secured Notes [Member] | Ipalco Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate			3.45%							3.45%
Ratio of principal to public offering price						99.929%
Proceeds from Issuance of Secured Debt						$ 399,500,000
Long-term debt			$ 405,000,000							$ 405,000,000	0
Debt instrument, maturity date										Jul. 1, 2020
First Mortgage Bond 6.30% Due July 2013 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate									6.30%
First Mortgage Bond 4.65% Due June 2043 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Aggregate principal amount									$ 170,000,000		170,000,000
Debt instrument, stated interest rate			4.65%						4.65%	4.65%
Net proceeds from debt issuance									$ 167,900,000
Debt instrument, maturity date										Jun. 1, 2043
First mortgage bonds			$ 170,000,000							$ 170,000,000	170,000,000
First Mortgage Bond 4.70% Due September 2045 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Aggregate principal amount					$ 260,000,000		$ 130,000,000
Debt instrument, stated interest rate			4.70%		4.70%		4.50%			4.70%
Net proceeds from debt issuance							$ 126,800,000
Proceeds from Issuance of Secured Debt					$ 255,600,000
Debt instrument, maturity date										Sep. 1, 2045
First mortgage bonds			$ 260,000,000							$ 260,000,000	0
7.25% Senior Secured Notes [Member] | Ipalco Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate			7.25%							7.25%
Refunded aggregate principal						366,500,000
Long-term debt			$ 0			33,500,000				$ 0	400,000,000
Debt instrument, maturity date										Apr. 1, 2016
Accounts Receivable Securitization Program [Member]
Debt Instrument [Line Items]
Refunded aggregate principal	$ 50,000,000
Accounts Receivable Securitization Program [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Refunded aggregate principal	$ 50,000,000			$ 50,000,000
2011 IPALCO Notes [Member] | First Mortgage Bond 4.65% Due June 2043 [Member]
Debt Instrument [Line Items]
Early tender premium									110,000,000
2011 IPALCO Notes [Member] | First Mortgage Bond 4.65% Due June 2043 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Early tender premium									$ 110,000,000
Medium-term Notes [Member] | Unsecured 364-day Taxable Term Loan [Member]
Debt Instrument [Line Items]
Aggregate principal amount		$ 91,850,000
Line of credit facility, term		364 days
Long-term debt		$ 50,000,000
Medium-term Notes [Member] | Unsecured 364-day Taxable Term Loan [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Aggregate principal amount		$ 91,850,000		$ 91,900,000
Line of credit facility, term		364 days		364 days
Long-term debt		$ 50,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Authorized amount of debt to be refinanced			90,000,000							$ 90,000,000
Unsecured Debt [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Authorized amount of debt to be refinanced			90,000,000							90,000,000
Unsecured Debt [Member] | Environmental Facilities Refunding Revenue Notes [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Aggregate principal amount			$ 90,000,000							$ 90,000,000
Number of note series | note_series			2							2
Unsecured Debt [Member] | Environmental Facilities Refunding Revenue Notes, Series 2015A [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Aggregate principal amount			$ 30,000,000							$ 30,000,000
Unsecured Debt [Member] | Environmental Facilities Refunding Revenue Notes, Series 2015B [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Aggregate principal amount			60,000,000							60,000,000
Secured Debt [Member] | First Mortgage Bond 4.90% Due January 2016 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Refunded aggregate principal			30,000,000
Secured Debt [Member] | First Mortgage Bond 4.90% Due January 2016 [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Refunded aggregate principal			60,000,000
Line of Credit [Member] | Committed Line of Credit [Member]
Debt Instrument [Line Items]
Long-term Line of Credit			75,000,000							75,000,000	0
Line of Credit [Member] | Indianapolis Power And Light Company [Member] | Committed Line of Credit [Member]
Debt Instrument [Line Items]
Long-term Line of Credit			$ 75,000,000							$ 75,000,000	$ 0
Other Nonoperating Income (Expense) [Member] | 7.25% Senior Secured Notes [Member] | Ipalco Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Charges related to early extinguishment of debt						$ 22,100,000

Debt (Schedule Long-Term Indebt

Debt (Schedule Long-Term Indebtedness) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Jun. 30, 2013
Debt Instrument [Line Items]
Unamortized discount - net	$ (4,600)			$ (4,300)
Long-term debt	2,173,837			1,951,013
Current portion of long-term debt	0			0
Long-term debt	2,173,837			1,951,013
Ipalco Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Unamortized discount - net	(371)			(1,347)
Long-term debt	804,629			798,653
Current portion of long-term debt	0			0
Long-term debt	804,629			798,653
Ipalco Enterprises, Inc. [Member] | 7.25% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 0		$ 33,500	400,000
Debt, stated interest rate	7.25%
Debt due date	Apr. 1, 2016
Ipalco Enterprises, Inc. [Member] | 5.00% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 400,000			400,000
Debt, stated interest rate	5.00%
Debt due date	May 1, 2018
Ipalco Enterprises, Inc. [Member] | 3.45% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term debt	$ 405,000			0
Debt, stated interest rate	3.45%
Debt due date	Jul. 1, 2020
Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 1,279,208			1,152,360
Unamortized discount - net	(4,242)			(2,940)
Unsecured Debt	90,000			0
Long-term debt	1,369,208			1,152,360
Current portion of long-term debt	0			0
Long-term debt	1,369,208			1,152,360
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.90% Due January 2016 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 0			30,000
Debt, stated interest rate	4.90%
Debt due date	Jan. 1, 2016
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.90% Due January 2016 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 0			41,850
Debt, stated interest rate	4.90%
Debt due date	Jan. 1, 2016
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.90% Due January 2016 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 0			60,000
Debt, stated interest rate	4.90%
Debt due date	Jan. 1, 2016
Indianapolis Power And Light Company [Member] | First Mortgage Bond 5.40% Due August 2017 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 24,650			24,650
Debt, stated interest rate	5.40%
Debt due date	Aug. 1, 2017
Indianapolis Power And Light Company [Member] | First Mortgage Bond 3.875% Due August 2021 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 55,000			55,000
Debt, stated interest rate	3.875%
Debt due date	Aug. 1, 2021
Indianapolis Power And Light Company [Member] | First Mortgage Bond 3.875% Due August 2021 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 40,000			40,000
Debt, stated interest rate	3.875%
Debt due date	Aug. 1, 2021
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.55% Due December 2024 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 40,000			40,000
Debt, stated interest rate	4.55%
Debt due date	Dec. 1, 2024
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.60% Due January 2034 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 100,000			100,000
Debt, stated interest rate	6.60%
Debt due date	Jan. 1, 2034
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.05% Due October 2036 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 158,800			158,800
Debt, stated interest rate	6.05%
Debt due date	Oct. 1, 2036
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.60% Due June 2037 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 165,000			165,000
Debt, stated interest rate	6.60%
Debt due date	Jun. 1, 2037
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.875% Due November 2041 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 140,000			140,000
Debt, stated interest rate	4.875%
Debt due date	Nov. 1, 2041
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.65% Due June 2043 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 170,000			170,000
Debt, stated interest rate	4.65%					4.65%
Debt due date	Jun. 1, 2043
Indianapolis Power And Light Company [Member] | First Mortgage Bond Nineteen [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 130,000			130,000
Debt, stated interest rate	4.50%
Debt due date	Jun. 1, 2044
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.70% Due September 2045 [Member]
Debt Instrument [Line Items]
First mortgage bonds	$ 260,000			0
Debt, stated interest rate	4.70%	4.70%			4.50%
Debt due date	Sep. 1, 2045
Indianapolis Power And Light Company [Member] | Environmental Facilities Refunding Revenue Notes, Series 2015A [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 30,000			0
Debt due date	Dec. 1, 2020
Indianapolis Power And Light Company [Member] | Environmental Facilities Refunding Revenue Notes, Series 2015B [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 60,000			$ 0
Debt due date	Dec. 1, 2020

Debt (Schedule Of Maturities On

Debt (Schedule Of Maturities On Long-Term Indebtedness) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Entity Information [Line Items]
2,016	$ 0
2,017	24,650
2,018	400,000
2,019	0
2,020	495,000
Thereafter	1,258,800
Total	2,178,450
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
2,016	0
2,017	24,650
2,018	0
2,019	0
2,020	90,000
Thereafter	1,258,800
Total	$ 1,373,450

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	Mar. 25, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Entity Information [Line Items]
Additional reduction to the state corporate income tax rate	1.60%
Reduction to the state corporate income tax rate	2.00%
Favorable tax adjustment		$ 245,900,000
Decrease in deferred taxes		1,000,000
Tax benefit from temporary differences		$ 400,000
Statutory state income tax rate			6.75%
Percentage of qualifying production activity eligible for deduction		9.00%
Income tax expense (benefit) from qualifying production activity		$ 0	$ 0	$ 3,700,000
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Additional reduction to the state corporate income tax rate	1.60%
Reduction to the state corporate income tax rate	2.00%
Favorable tax adjustment		245,900,000
Decrease in deferred taxes		1,000,000
Tax benefit from temporary differences		$ 400,000
Statutory state income tax rate			6.75%
Percentage of qualifying production activity eligible for deduction		9.00%
Income tax expense (benefit) from qualifying production activity		$ 1,700,000	$ 0	$ 4,400,000

Income Taxes (Schedule Of Feder

Income Taxes (Schedule Of Federal And State Income Taxed Charged To Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Total current income taxes	$ 57,284	$ 70,235	$ 58,548
Income Tax Expense (Benefit), Total	31,566	48,044	37,742
Charged To Utility Operating Expense [Member]
Income Taxes [Line Items]
Current income taxes, Federal	18,661	944	53,937
Current income taxes, State	5,758	110	15,191
Total current income taxes	24,419	1,054	69,128
Deferred income taxes, Federal	29,165	58,114	(8,048)
Deferred income taxes, State	5,019	12,498	(1,031)
Total deferred income taxes	34,184	70,612	(9,079)
Net amortization of investment credit	(1,319)	(1,431)	(1,501)
Income Tax Expense (Benefit), Total	57,284	70,235	58,548
Charged To Other Income And Deductions [Member]
Income Taxes [Line Items]
Current income taxes, Federal	(18,661)	(459)	(16,909)
Current income taxes, State	(5,758)	(5)	(4,193)
Total current income taxes	(24,419)	(464)	(21,102)
Deferred income taxes, Federal	(2,573)	(18,082)	246
Deferred income taxes, State	1,274	(3,645)	50
Total deferred income taxes	(1,299)	(21,727)	296
Income Tax Expense (Benefit), Total	(25,718)	(22,191)	(20,806)
Indianapolis Power And Light Company [Member]
Income Taxes [Line Items]
Total current income taxes	57,284	70,235	58,548
Income Tax Expense (Benefit), Total	56,219	69,283	57,720
Indianapolis Power And Light Company [Member] | Charged To Utility Operating Expense [Member]
Income Taxes [Line Items]
Current income taxes, Federal	18,661	944	53,937
Current income taxes, State	5,758	110	15,191
Total current income taxes	24,419	1,054	69,128
Deferred income taxes, Federal	29,165	58,114	(8,048)
Deferred income taxes, State	5,019	12,498	(1,031)
Total deferred income taxes	34,184	70,612	(9,079)
Net amortization of investment credit	(1,319)	(1,431)	(1,501)
Income Tax Expense (Benefit), Total	57,284	70,235	58,548
Indianapolis Power And Light Company [Member] | Charged To Other Income And Deductions [Member]
Income Taxes [Line Items]
Current income taxes, Federal	(1,715)	329	(752)
Current income taxes, State	(240)	69	(62)
Total current income taxes	(1,955)	398	(814)
Deferred income taxes, Federal	740	(1,202)	(13)
Deferred income taxes, State	150	(148)	(1)
Total deferred income taxes	890	(1,350)	(14)
Income Tax Expense (Benefit), Total	$ (1,065)	$ (952)	$ (828)

Income Taxes (Schedule Of Effec

Income Taxes (Schedule Of Effective Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Entity Information [Line Items]
Federal statutory tax rate	35.00%	35.00%	35.00%
State income tax, net of federal tax benefit	4.70%	4.80%	6.70%
Amortization of investment tax credits	(1.50%)	(1.20%)	(1.50%)
Preferred dividends of subsidiary	1.30%	0.90%	1.10%
Depreciation flow through and amortization	(0.30%)	(0.30%)	(0.30%)
Additional funds used during construction - equity	(3.50%)	(0.30%)	0.60%
Manufacturers' Production Deduction (Sec. 199)	(0.00%)	(0.00%)	(3.80%)
Other - net	0.20%	0.20%	0.50%
Effective tax rate	35.90%	39.10%	38.30%
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Federal statutory tax rate	35.00%	35.00%	35.00%
State income tax, net of federal tax benefit	4.40%	4.60%	6.00%
Amortization of investment tax credits	(0.80%)	(0.80%)	(1.00%)
Depreciation flow through and amortization	(0.20%)	(0.20%)	(0.20%)
Additional funds used during construction - equity	(1.90%)	(0.20%)	0.40%
Manufacturers' Production Deduction (Sec. 199)	(1.00%)	(0.00%)	(3.20%)
Other - net	0.10%	0.40%	0.40%
Effective tax rate	35.60%	38.80%	37.40%

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Entity Information [Line Items]
Relating to utility property, net	$ 541,369	$ 539,318
Regulatory assets recoverable through future rates	178,187	161,697
Other	11,768	14,211
Total deferred tax liabilities	731,324	715,226
Investment tax credit	1,507	2,019
Regulatory liabilities including ARO	260,555	247,118
Employee benefit plans	38,159	45,091
Net operating loss	23,161	51,364
Other	10,548	10,289
Total deferred tax assets	333,930	355,881
Net deferred tax liability	397,394	359,345
Less: deferred tax asset - current	0	(61,782)
Deferred income taxes – net	397,394	421,127
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Relating to utility property, net	541,369	539,318
Regulatory assets recoverable through future rates	178,187	161,697
Other	11,349	13,885
Total deferred tax liabilities	730,905	714,900
Investment tax credit	1,507	2,019
Regulatory liabilities including ARO	260,555	247,118
Employee benefit plans	38,159	45,090
Net operating loss	0	31,172
Other	10,953	10,008
Total deferred tax assets	311,174	335,407
Net deferred tax liability	419,731	379,493
Less: deferred tax asset - current	0	(41,551)
Deferred income taxes – net	$ 419,731	$ 421,044

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits at January 1	$ 7,042	$ 6,734	$ 6,138
Gross increases - current period tax positions	962	975	986
Gross decreases - prior period tax positions	(857)	(667)	(390)
Unrecognized tax benefits at December 31	7,147	7,042	6,734
Indianapolis Power And Light Company [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits at January 1	7,042	6,734	6,138
Gross increases - current period tax positions	962	975	986
Gross decreases - prior period tax positions	(857)	(667)	(390)
Unrecognized tax benefits at December 31	$ 7,147	$ 7,042	$ 6,734

Benefit Plans (Narrative) (Deta

Benefit Plans (Narrative) (Details) $ in Thousands	Jan. 01, 2016	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)employee	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities			$ 76,314	$ 91,182
Benefit obligation in excess of plan assets			76,314	91,182
Accumulated benefit obligation in excess of plan assets			64,724	77,089
Net loss (gain) arising during period			11,757	58,439
Amount included in regulatory assets and liabilities			209,252	211,592
Benefit obligation			723,887	748,421
Plan assets			$ 647,573	657,239
Expected return on plan assets			6.75%
Effect of 25 basis point increase in discount rate on pension expense			$ (1,300)
Effect of 25 basis point decrease in discount rate on pension expense			1,400
Amortization of net losses from regulatory assets			13,900
Amortization of net periodic benefit cost from regulatory assets			5,200
Employer contributions during quarter			$ 25,166	54,109	$ 49,700
Funded target liability (percent)			112.00%
Normal service cost			$ 7,100
Plan expenses			2,300
Required funding in next fiscal year			15,900
Pension expense			35,700	32,600
Service cost			8,314	7,231	9,195
Interest cost			$ 29,638	$ 31,154	$ 28,363
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			77.00%
Benefit obligation in excess of plan assets			$ (75,300)
Accumulated benefit obligation in excess of plan assets			$ 63,700
Discount rate			4.06%	4.92%	3.80%
Expected return on plan assets			6.75%	7.00%	7.25%
Amortization of net losses from regulatory assets			$ 13,700
Amortization of net periodic benefit cost from regulatory assets			$ 5,200
Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of plan participants | employee			24
Benefit obligation in excess of plan assets			$ (1,000)
Accumulated benefit obligation in excess of plan assets			$ 1,000
Discount rate			3.82%	4.64%	3.41%
Expected return on plan assets			6.75%	7.00%	7.25%
Amortization of net losses from regulatory assets			$ 200
Amortization of net periodic benefit cost from regulatory assets			$ 0
Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of plan participants, active | employee			171
Number of plan participants, retired | employee			27
Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities			$ 76,314	$ 91,182
Benefit obligation in excess of plan assets			76,314	91,182
Accumulated benefit obligation in excess of plan assets			64,724	77,089
Net loss (gain) arising during period			11,757	58,439
Pension liability actuarial loss			43,800
Pension liability actuarial loss, change in discount rate			32,000
Amount included in regulatory assets and liabilities			$ 209,252	211,592
Minimum percentage of unrecognized net loss over benefit obligation or assets in order to be amortized			10.00%
Amortization period of unrecognized loss			9 years 9 months 7 days
Benefit obligation			$ 723,887	748,421
Plan assets			647,573	657,239
Unfunded status of plan			$ (76,300)
Expected return on plan assets			6.75%
Effect of 25 basis point increase in discount rate on pension expense			$ (1,300)
Effect of 25 basis point decrease in discount rate on pension expense			1,400
Amortization of net losses from regulatory assets			13,900
Amortization of net periodic benefit cost from regulatory assets			5,200
Employer contributions during quarter			25,166	54,109	$ 49,700
Pension expense			35,700	32,600
Service cost			8,314	7,231	9,195
Interest cost			$ 29,638	$ 31,154	$ 28,363
Indianapolis Power And Light Company [Member] | Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			77.00%
Benefit obligation in excess of plan assets			$ 75,300
Accumulated benefit obligation in excess of plan assets			$ 63,700
Discount rate			4.06%	4.92%	3.80%
Expected return on plan assets			6.75%	7.00%	7.25%
Amortization of net losses from regulatory assets			$ 13,700
Amortization of net periodic benefit cost from regulatory assets			$ 5,200
Indianapolis Power And Light Company [Member] | Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of plan participants | employee			24
Benefit obligation in excess of plan assets			$ 1,000
Accumulated benefit obligation in excess of plan assets			$ 1,000
Discount rate			3.82%	4.64%	3.41%
Expected return on plan assets			6.75%	7.00%	7.25%
Amortization of net losses from regulatory assets			$ 200
Amortization of net periodic benefit cost from regulatory assets			$ 0
Indianapolis Power And Light Company [Member] | Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of plan participants, active | employee			171
Number of plan participants, retired | employee			27
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	6.75%
Subsequent Event [Member] | Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.42%
Subsequent Event [Member] | Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.19%
Subsequent Event [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	6.75%
Subsequent Event [Member] | Indianapolis Power And Light Company [Member] | Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.42%
Subsequent Event [Member] | Indianapolis Power And Light Company [Member] | Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.19%
Thrift Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			84.00%
Defined contripution plan contributions			$ 3,100	$ 3,000	$ 3,000
Thrift Plan [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			84.00%
Defined contripution plan contributions			$ 3,100	3,000	3,000
Retirement Savings Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			16.00%
Percentage of employee's base compensation matched			5.00%
Defined contripution plan contributions			$ 300	1,500	1,800
Retirement Savings Plan [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			16.00%
Percentage of employee's base compensation matched			5.00%
Defined contripution plan contributions			$ 300	$ 1,500	$ 1,800
Union Employees [Member] | Thrift Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			7.00%
Union Employees [Member] | Thrift Plan [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees covered by the plan			7.00%
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 400
Interest cost		5,300
Scenario, Forecast [Member] | Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		400
Interest cost		5,300
Scenario, Forecast [Member] | Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		0
Interest cost		0
Scenario, Forecast [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		400
Interest cost		5,300
Scenario, Forecast [Member] | Indianapolis Power And Light Company [Member] | Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		400
Interest cost		5,300
Scenario, Forecast [Member] | Indianapolis Power And Light Company [Member] | Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		0
Interest cost		$ 0

Benefit Plans (Schedule Of Defi

Benefit Plans (Schedule Of Defined Benefit Plans Disclosures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in benefit obligation:
Projected benefit obligation at beginning Measurement Date (see below)	$ 748,421	$ 650,713
Service cost	8,314	7,231	$ 9,195
Interest cost	29,638	31,154	28,363
Actuarial (gain) loss	(31,989)	90,693
Amendments (primarily increases in pension bands)	5,409	1,233
Settlements	(395)	0
Benefits paid	(35,511)	(32,603)
Projected benefit obligation at ending Measurement Date	723,887	748,421	650,713
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	657,239	561,586
Actual return on plan assets	1,074	74,147
Employer contributions during quarter	25,166	54,109	49,700
Settlements	(395)	0
Benefits paid	(35,511)	(32,603)
Fair value of plan assets at ending Measurement Date	647,573	657,239	561,586
Unfunded status	(76,314)	(91,182)
Amounts recognized in the statement of financial position under ASC 715:
Noncurrent liabilities	(76,314)	(91,182)
Net amount recognized	(76,314)	(91,182)
Sources of change in regulatory assets(1):
Prior service cost (credit) arising during period	5,409	1,233
Net loss (gain) arising during period	11,757	58,439
Amortization of prior service cost	(4,867)	(4,853)	(4,916)
Amortization of gain (loss)	(14,096)	(9,710)
Total recognized in regulatory assets	(1,797)	45,109
Net loss (gain)	209,252	211,592
Prior service cost (credit)	25,842	25,299
Total amounts included in regulatory assets (liabilities)	235,094	236,891
Indianapolis Power And Light Company [Member]
Change in benefit obligation:
Projected benefit obligation at beginning Measurement Date (see below)	748,421	650,713
Service cost	8,314	7,231	9,195
Interest cost	29,638	31,154	28,363
Actuarial (gain) loss	(31,989)	90,693
Amendments (primarily increases in pension bands)	5,409	1,233
Settlements	(395)	0
Benefits paid	(35,511)	(32,603)
Projected benefit obligation at ending Measurement Date	723,887	748,421	650,713
Change in plan assets:
Fair value of plan assets at beginning Measurement Date	657,239	561,586
Actual return on plan assets	1,074	74,147
Employer contributions during quarter	25,166	54,109	49,700
Settlements	(395)	0
Benefits paid	(35,511)	(32,603)
Fair value of plan assets at ending Measurement Date	647,573	657,239	561,586
Unfunded status	(76,314)	(91,182)
Amounts recognized in the statement of financial position under ASC 715:
Noncurrent liabilities	(76,314)	(91,182)
Net amount recognized	(76,314)	(91,182)
Sources of change in regulatory assets(1):
Prior service cost (credit) arising during period	5,409	1,233
Net loss (gain) arising during period	11,757	58,439
Amortization of prior service cost	(4,867)	(4,853)	$ (4,916)
Amortization of gain (loss)	(14,096)	(9,710)
Total recognized in regulatory assets	(1,797)	45,109
Net loss (gain)	209,252	211,592
Prior service cost (credit)	25,842	25,299
Total amounts included in regulatory assets (liabilities)	$ 235,094	$ 236,891

Benefit Plans (Information For

Benefit Plans (Information For Pension Plans With A Benefit Obligation In Excess Of Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Entity Information [Line Items]
Benefit obligation	$ 723,887	$ 748,421
Plan assets	647,573	657,239
Benefit obligation in excess of plan assets	76,314	91,182
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Benefit obligation	723,887	748,421
Plan assets	647,573	657,239
Benefit obligation in excess of plan assets	$ 76,314	$ 91,182

Benefit Plans (Information Fo56

Benefit Plans (Information For Pension Plans With An Accumulated Benefit Obligation In Excess Of Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Entity Information [Line Items]
Accumulated benefit obligation	$ 712,297	$ 734,328
Plan assets	647,573	657,239
Accumulated benefit obligation in excess of plan assets	64,724	77,089
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Accumulated benefit obligation	712,297	734,328
Plan assets	647,573	657,239
Accumulated benefit obligation in excess of plan assets	$ 64,724	$ 77,089

Benefit Plans (Schedule Of Net

Benefit Plans (Schedule Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8,314	$ 7,231	$ 9,195
Interest cost	29,638	31,154	28,363
Expected return on assets	(44,819)	(41,893)	(38,287)
Amortization of prior service cost	4,867	4,853	4,916
Recognized actuarial loss	13,890	9,710	22,735
Recognized settlement loss	206	0	0
Net periodic benefit cost	12,096	11,055	26,922
Less: amounts capitalized	1,403	1,426	2,881
Amount charged to expense	$ 10,693	9,629	24,041
Expected return on plan assets	6.75%
MRVA, comparison period	3 years
MRVA used in calculation of expected return on pension plan assets	$ 643,000	652,200	556,400
Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	8,314	7,231	9,195
Interest cost	29,638	31,154	28,363
Expected return on assets	(44,819)	(41,893)	(38,287)
Amortization of prior service cost	4,867	4,853	4,916
Recognized actuarial loss	13,890	9,710	22,735
Recognized settlement loss	206	0	0
Net periodic benefit cost	12,096	11,055	26,922
Less: amounts capitalized	1,403	1,426	2,881
Amount charged to expense	$ 10,693	9,629	24,041
Expected return on plan assets	6.75%
MRVA, comparison period	3 years
MRVA used in calculation of expected return on pension plan assets	$ 643,000	$ 652,200	$ 556,400
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.06%	4.92%	3.80%
Expected return on plan assets	6.75%	7.00%	7.25%
Pension Benefit [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.06%	4.92%	3.80%
Expected return on plan assets	6.75%	7.00%	7.25%
Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.82%	4.64%	3.41%
Expected return on plan assets	6.75%	7.00%	7.25%
Supplemental Retirement Plan [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.82%	4.64%	3.41%
Expected return on plan assets	6.75%	7.00%	7.25%

Benefit Plans (Schedule Of Asse

Benefit Plans (Schedule Of Asset Allocation Guidelines) (Details)	12 Months Ended
	Dec. 31, 2015
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	60.00%
Equity Securities [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	60.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	40.00%
Debt Securities [Member] | Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	40.00%

Benefit Plans (Schedule Of Fair

Benefit Plans (Schedule Of Fair Value Of Pension Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 647,573	$ 657,239	$ 561,586
Percentage by asset category	100.00%	100.00%
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 647,573	$ 656,929
Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		310
Short-Term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 176	$ 2,575
Percentage by asset category	0.00%	0.00%
Short-Term Investments [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 176	$ 2,575
U.S. Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 318,368	$ 325,370
Percentage by asset category	49.00%	50.00%
U.S. Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 318,368	$ 325,370
International Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 60,751	$ 56,662
Percentage by asset category	10.00%	9.00%
International Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 60,751	$ 56,662
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 215,325	$ 205,409
Percentage by asset category	33.00%	31.00%
Fixed Income [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 215,325	$ 205,409
US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 52,953	$ 66,913
Percentage by asset category	8.00%	10.00%
US Treasury Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 52,953	$ 66,913
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 310
Percentage by asset category		0.00%
Hedge Funds [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 310
Indianapolis Power And Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 647,573	$ 657,239	$ 561,586
Percentage by asset category	100.00%	100.00%
Indianapolis Power And Light Company [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 647,573	$ 656,929
Indianapolis Power And Light Company [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	0	310
Indianapolis Power And Light Company [Member] | Short-Term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 176	$ 2,575
Percentage by asset category	0.00%	0.00%
Indianapolis Power And Light Company [Member] | Short-Term Investments [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 176	$ 2,575
Indianapolis Power And Light Company [Member] | U.S. Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 318,368	$ 325,370
Percentage by asset category	49.00%	50.00%
Indianapolis Power And Light Company [Member] | U.S. Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 318,368	$ 325,370
Indianapolis Power And Light Company [Member] | International Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 60,751	$ 56,662
Percentage by asset category	10.00%	9.00%
Indianapolis Power And Light Company [Member] | International Equities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 60,751	$ 56,662
Indianapolis Power And Light Company [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 215,325	$ 205,409
Percentage by asset category	33.00%	31.00%
Indianapolis Power And Light Company [Member] | Fixed Income [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 215,325	$ 205,409
Indianapolis Power And Light Company [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 52,953	$ 66,913
Percentage by asset category	8.00%	10.00%
Indianapolis Power And Light Company [Member] | US Treasury Securities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets	$ 52,953	$ 66,913
Indianapolis Power And Light Company [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 310
Percentage by asset category		0.00%
Indianapolis Power And Light Company [Member] | Hedge Funds [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of benefit plan assets		$ 310

Benefit Plans (Schedule Of Expe

Benefit Plans (Schedule Of Expected Benefit Payments) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Entity Information [Line Items]
2,016	$ 38,289
2,017	39,909
2,018	41,213
2,019	42,638
2,020	43,920
2021 through 2025 (in total)	233,449
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
2,016	38,289
2,017	39,909
2,018	41,213
2,019	42,638
2,020	43,920
2021 through 2025 (in total)	$ 233,449

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details)	1 Months Ended
	Oct. 31, 2009coal_fired_electric_generating_facility
Indianapolis Power And Light Company [Member]
Entity Information [Line Items]
Number of facilities with violations of Federal Clean Air Act	3

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Self-insured retention per occurrence	$ 5
Insurance expense	2.7	$ 3.2	$ 3.1
Prepaid insurance	2.2	3.1
Health coverage expense	24.5	20.1	22.3
Prepaid health coverage	0	0.1
Income taxes receivable	$ 0.7
Deferred compensation arrangement vesting period	3 years
Deferred compensation arrangement holding period	2 years
Deferred compensation expense	$ 0.7	0.7	1.1
Service Company [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	23.2	22
Prepaid balance to related party	1.2	0.4
Director [Member]
Related Party Transaction [Line Items]
Billings from related party	232	80.3
Accounts payable to related vendor	34	11.9
Ipalco Enterprises, Inc. [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	7.5	5.6
Indianapolis Power And Light Company [Member]
Related Party Transaction [Line Items]
Self-insured retention per occurrence	5
Insurance expense	2.7	3.2	3.1
Prepaid insurance	2.2	3.1
Health coverage expense	24.5	20.1	22.3
Prepaid health coverage	0	0.1
Income taxes receivable	$ 2.8	0.3
Deferred compensation arrangement vesting period	3 years
Deferred compensation arrangement holding period	2 years
Deferred compensation expense	$ 0.7	0.7	$ 1.1
Costs incurred by related party	7.5	5.6
Prepaid balance to related party	1.2	0.4
Indianapolis Power And Light Company [Member] | Service Company [Member]
Related Party Transaction [Line Items]
Costs incurred by related party	22.6	22
Indianapolis Power And Light Company [Member] | Director [Member]
Related Party Transaction [Line Items]
Billings from related party	232	80.3
Accounts payable to related vendor	$ 34	$ 11.9

Business Segment Information (D

Business Segment Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)segment	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Cash	$ 1.7	$ 5.9
Long-term nonutility investments	$ 5.2	$ 5.1
Nonutility assets representation rate, (percent, less than)	1.00%	1.00%
Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Reportable segments | segment	1

Business Segment Information (S

Business Segment Information (Summary Of Company's Reporting Segments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Operating revenues	$ 1,250,399	$ 1,321,674	$ 1,255,734
Depreciation and amortization	188,267	185,263	182,305
Tax benefit	31,566	48,044	37,742
Net income	59,524	77,968	64,049
Utility plant - net of depreciation	3,451,383	2,856,634	2,553,000
Capital expenditures	686,000	382,000	242,000
Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues	1,250,000	1,322,000	1,256,000
Depreciation and amortization	188,000	185,000	182,000
Tax benefit	56,000	69,000	58,000
Net income	102,000	110,000	97,000
Utility plant - net of depreciation	3,451,000	2,857,000	2,553,000
Capital expenditures	686,000	382,000	242,000
Other Segments [Member]
Segment Reporting Information [Line Items]
Tax benefit	(25,000)	(21,000)	(20,000)
Net income	$ (42,000)	$ (32,000)	$ (33,000)

Retrospective Adoption of ASU65

Retrospective Adoption of ASU 2015-03 (Details) - Adjustments for New Accounting Pronouncement [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred financing costs	$ 20.8	$ 15.3
Indianapolis Power And Light Company [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred financing costs	$ 13.9	$ 10.7

Schedule I - Condensed Financ66

Schedule I - Condensed Financial Information Of Registrant (Narrative) (Details) $ in Thousands	Apr. 01, 2015USD ($)shares	Feb. 11, 2015USD ($)itemshares	Jun. 27, 2014USD ($)	Jul. 31, 2013USD ($)	Jun. 30, 2015	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Condensed Financial Statements, Captions [Line Items]
Equity contributions from AES						$ 0	$ 106,400	$ 49,091
Common shares issued | shares		100
Ownership percentage by parent						88.40%
Common stock issued and sold to CDPQ						$ 214,366
Ipalco Enterprises, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Equity contributions from AES			$ 106,400	$ 49,100		0	$ 106,400	$ 49,091
Additional investment through agreement		$ 349,000
Direct and indirect ownership percentage		30.00%
Increase in ownership percentage after investment		17.65%
Ownership percentage by parent		82.35%
Number of board members | item		11
Common stock issued and sold to CDPQ						$ 214,366
AES U.S. Investments [Member]
Condensed Financial Statements, Captions [Line Items]
Ownership Percentage by Non-controlling Interest						15.00%
Ownership percentage by parent		85.00%
Number of board members | item		9
CDPQ [Member]
Condensed Financial Statements, Captions [Line Items]
Minimum ownership percentage to retain board members		5.00%
Ownership percentage by parent					11.60%
Number of board members | item		2
Percentage Of Direct And Indirect Ownership Share Of IPALCO	24.90%
Common Stock [Member]
Condensed Financial Statements, Captions [Line Items]
Common stock issued and sold to CDPQ (shares) | shares	11,818,828
Common stock issued and sold to CDPQ	$ 214,400
Common Stock [Member] | Ipalco Enterprises, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Common stock issued and sold to CDPQ (shares) | shares	11,818,828
Common stock issued and sold to CDPQ	$ 214,400

Schedule I - Condensed Financ67

Schedule I - Condensed Financial Information Of Registrant (Unconsolidated Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 21,521	$ 26,933	$ 19,067	$ 18,487
Deferred tax asset - current	0	61,782
Prepayments and other current assets	26,063	23,161
Total current assets	304,584	359,413
Other long-term assets	5,664	6,221
Other assets - net	6,181	6,743
TOTAL	4,217,169	3,652,522
Paid in capital	383,448	168,610
Accumulated deficit	(30,515)	(17,339)
Total common shareholder's deficit	352,933	151,271
Long-term debt	2,153,276	1,935,717
Total capitalization	2,565,993	2,146,772
Accrued interest	31,690	30,726
Total current liabilities	462,478	304,874
Total deferred credits and other long-term liabilities	1,188,698	1,200,876
TOTAL	4,217,169	3,652,522
Ipalco Enterprises, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	774	1,785	$ 2,790	$ 2,750
Deferred tax asset - current	0	20,231
Prepayments and other current assets	10,608	165
Total current assets	11,382	22,181
Investment in subsidiaries	1,127,098	930,554
Other long-term assets	3,316	3,178
Deferred tax asset - long term	22,702	282
Other assets - net	1,153,116	934,014
TOTAL	1,164,498	956,195
Paid in capital	383,448	168,610
Accumulated deficit	(30,515)	(17,339)
Total common shareholder's deficit	352,933	151,271
Long-term debt	797,771	794,090
Total capitalization	1,150,704	945,361
Accounts payable and accrued expenses	383	251
Accrued income taxes	2,857	0
Accrued interest	10,552	10,583
Total current liabilities	13,792	10,834
Total deferred credits and other long-term liabilities	2	0
TOTAL	$ 1,164,498	$ 956,195

Schedule I - Condensed Financ68

Schedule I - Condensed Financial Information Of Registrant (Unconsolidated Statements Of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Loss on early extinguishment of debt	$ (21,956)	$ 0	$ (35)
Income taxes - net	31,566	48,044	37,742
Interest on long-term debt	(106,936)	(108,104)	(104,602)
Amortization of redemption premiums and expense on debt	(5,067)	(5,275)	(5,075)
NET INCOME	59,524	77,968	64,049
Ipalco Enterprises, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Equity in earnings of subsidiaries	98,708	106,252	93,344
Loss on early extinguishment of debt	(21,956)	0	0
Income taxes - net	24,650	21,227	19,971
Interest on long-term debt	(41,659)	(49,000)	(49,000)
Amortization of redemption premiums and expense on debt	(2,459)	(2,765)	(2,581)
Other -net	(973)	(959)	(898)
NET INCOME	$ 56,311	$ 74,755	$ 60,836

Schedule I - Condensed Financ69

Schedule I - Condensed Financial Information Of Registrant (Unconsolidated Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	Jun. 27, 2014	Jul. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Net income			$ 59,524	$ 77,968	$ 64,049
Amortization of debt issuance costs and discounts			5,067	5,275	5,075
Income taxes receivable or payable			0	590	3,026
Accounts payable and accrued expenses			(716)	(24,322)	16,124
Other - net			6,654	809	6,983
Net cash provided by operating activities			252,425	253,997	211,375
Net cash used in investing activities			(695,117)	(397,358)	(254,519)
Long-term borrowings, net of discount			753,350	128,358	169,728
Retirement of long-term debt			(552,179)	0	(110,377)
Dividends on common stock			(69,487)	(78,400)	(59,500)
Issuance of common stock			214,366	0	0
Equity contributions from AES			0	106,400	49,091
Other - net			(368)	(194)	(9)
Net cash provided by financing activities			437,280	151,227	43,724
Net change in cash and cash equivalents			(5,412)	7,866	580
Cash and cash equivalents at beginning of period			26,933	19,067	18,487
Cash and cash equivalents at end of period			21,521	26,933	19,067
Ipalco Enterprises, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Net income			56,311	74,755	60,836
Equity in earnings of subsidiaries			(98,708)	(106,252)	(93,344)
Cash dividends received from subsidiary companies			106,997	127,400	90,150
Amortization of debt issuance costs and discounts			2,459	2,765	2,581
Deferred income taxes - net			(2,190)	(20,445)	81
Charges related to early extinguishment of debt			21,956	0	377
Income taxes receivable or payable			2,465	(501)	(681)
Accounts payable and accrued expenses			(391)	(599)	(166)
Other - net			639	255	(312)
Net cash provided by operating activities			89,538	77,378	59,522
Investment in subsidiaries			(214,366)	(106,383)	(49,073)
Net cash used in investing activities			(214,366)	(106,383)	(49,073)
Long-term borrowings, net of discount			404,712	0	0
Retirement of long-term debt			(420,329)	0	0
Dividends on common stock			(69,487)	(78,400)	(59,500)
Issuance of common stock			214,366	0	0
Equity contributions from AES	$ 106,400	$ 49,100	0	106,400	49,091
Other - net			(5,445)	0	0
Net cash provided by financing activities			123,817	28,000	(10,409)
Net change in cash and cash equivalents			(1,011)	(1,005)	40
Cash and cash equivalents at beginning of period			1,785	2,790	2,750
Cash and cash equivalents at end of period			$ 774	$ 1,785	$ 2,790

Schedule I - Condensed Financ70

Schedule I - Condensed Financial Information Of Registrant (Unconsolidated Statements Of Common Shareholders' Deficit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 151,271	$ 47,774	$ (3,219)
Net income applicable to common stock	56,311	74,755	60,836
Distributions to AES	(69,487)	(78,400)	(59,500)
Issuance of common stock	214,366
Contributions from AES		106,400	49,091
Other	472	742	566
Ending Balance	352,933	151,271	47,774
Ipalco Enterprises, Inc. [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	151,271	47,774	(3,219)
Net income applicable to common stock	56,311	74,755	60,836
Distributions to AES	(69,487)	(78,400)	(59,500)
Issuance of common stock	214,366
Contributions from AES		106,400	49,091
Other	472	742	566
Ending Balance	352,933	151,271	47,774
Paid In Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	168,610	61,468	11,811
Issuance of common stock	214,366
Contributions from AES		106,400	49,091
Other	472	742	566
Ending Balance	383,448	168,610	61,468
Paid In Capital [Member] | Ipalco Enterprises, Inc. [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	168,610	61,468	11,811
Issuance of common stock	214,366
Contributions from AES		106,400	49,091
Other	472	742	566
Ending Balance	383,448	168,610	61,468
Accumulated Deficit [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(17,339)	(13,694)	(15,030)
Net income applicable to common stock	56,311	74,755	60,836
Distributions to AES	(69,487)	(78,400)	(59,500)
Ending Balance	(30,515)	(17,339)	(13,694)
Accumulated Deficit [Member] | Ipalco Enterprises, Inc. [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(17,339)	(13,694)	(15,030)
Net income applicable to common stock	56,311	74,755	60,836
Distributions to AES	(69,487)	(78,400)	(59,500)
Ending Balance	$ (30,515)	$ (17,339)	$ (13,694)

Schedule I - Condensed Financ71

Schedule I - Condensed Financial Information Of Registrant (Long-Term Indebtedness) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Unamortized discount - net		$ (4,600)	$ (4,300)
Long-term debt		2,173,837	1,951,013
Current portion of long-term debt		0	0
Net Long-term Debt		2,173,837	1,951,013
Charges related to early extinguishment of debt		21,956	0	$ 35
Ipalco Enterprises, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Unamortized discount - net		(371)	(1,347)
Long-term debt		804,629	798,653
Current portion of long-term debt		0	0
Net Long-term Debt		804,629	798,653
Charges related to early extinguishment of debt		21,956	0	$ 0
Ipalco Enterprises, Inc. [Member] | 7.25% Senior Secured Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt	$ 33,500	$ 0	400,000
Debt, stated interest rate		7.25%
Debt due date		Apr. 1, 2016
Refunded aggregate principal	$ 366,500
Ipalco Enterprises, Inc. [Member] | 5.00% Senior Secured Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt		$ 400,000	400,000
Debt, stated interest rate		5.00%
Debt due date		May 1, 2018
Ipalco Enterprises, Inc. [Member] | 3.45% Senior Secured Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt		$ 405,000	$ 0
Debt, stated interest rate		3.45%
Debt due date		Jul. 1, 2020
Ratio of principal to public offering price	99.929%
Proceeds from Issuance of Secured Debt	$ 399,500
Other Nonoperating Income (Expense) [Member] | Ipalco Enterprises, Inc. [Member] | 7.25% Senior Secured Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Charges related to early extinguishment of debt	$ 22,100

Schedule I - Condensed Financ72

Schedule I - Condensed Financial Information Of Registrant Schedule I - Condensed Financial Information of Registrant (Retrospective Adoption of ASU 2015-03) (Details) - Adjustments for New Accounting Pronouncement [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Deferred financing costs	$ 20.8	$ 15.3
Ipalco Enterprises, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Deferred financing costs	$ 6.9	$ 4.6

Schedule II - Valuation And Q73

Schedule II - Valuation And Qualifying Accounts And Reserves (Details) - Allowance for Doubtful Accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 2,076	$ 1,982	$ 2,047
Charged to Income	4,273	4,852	3,790
Net Write-offs	3,851	4,758	3,855
Balance at End of Period	2,498	2,076	1,982
Indianapolis Power And Light Company [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	2,076	1,982	2,047
Charged to Income	4,273	4,852	3,790
Net Write-offs	3,851	4,758	3,855
Balance at End of Period	$ 2,498	$ 2,076	$ 1,982