Ipalco Enterprises 10-Q 8 May 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 08, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2,018
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		108,907,318

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements Of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
UTILITY OPERATING REVENUES	$ 354,504	$ 336,909
Operation:
Fuel	67,857	70,735
Other operating expenses	68,183	64,460
Power purchased	56,194	49,021
Maintenance	33,498	30,027
Depreciation and amortization	55,326	52,544
Taxes other than income taxes	13,772	12,274
Income taxes - net	9,096	15,953
Total utility operating expenses	303,926	295,014
UTILITY OPERATING INCOME	50,578	41,895
OTHER INCOME AND (DEDUCTIONS):
Allowance for equity funds used during construction	5,102	6,425
Miscellaneous income and (deductions) - net	(1,660)	(11)
Income tax benefit applicable to nonoperating income	2,051	3,770
Total other income and (deductions) - net	5,493	10,184
INTEREST AND OTHER CHARGES:
Interest on long-term debt	28,735	29,121
Other interest	458	367
Allowance for borrowed funds used during construction	(6,440)	(5,482)
Amortization of redemption premiums and expense on debt	1,015	1,077
Total interest and other charges - net	23,768	25,083
NET INCOME	32,303	26,996
LESS: PREFERRED DIVIDENDS OF SUBSIDIARY	803	803
NET INCOME APPLICABLE TO COMMON STOCK	$ 31,500	$ 26,193

Unaudited Condensed Consolidat3

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
UTILITY PLANT:
Utility plant in service	$ 5,401,530	$ 5,385,053
Less accumulated depreciation	2,159,437	2,129,617
Utility plant in service - net	3,242,093	3,255,436
Construction work in progress	742,952	711,396
Spare parts inventory	14,106	13,157
Property held for future use	1,002	1,002
OTHER ASSETS:
Nonutility property - at cost, less accumulated depreciation	502	502
Intangible Assets, Net (Excluding Goodwill)	16,435	16,036
Other long-term assets	4,238	6,185
Other assets - net	21,175	22,723
CURRENT ASSETS:
Cash and cash equivalents	25,269	30,681
Accounts receivable and unbilled revenue (less allowance for doubtful accounts of $3,707 and $2,830 respectively)	153,433	157,577
Fuel inventories - at average cost	31,650	32,393
Materials and supplies - at average cost	65,656	63,623
Regulatory assets	38,433	35,341
Prepayments and other current assets	26,870	34,094
Total current assets	341,311	353,709
DEFERRED DEBITS:
Regulatory assets	375,264	378,904
Miscellaneous	4,188	4,234
Total deferred debits	379,452	383,138
TOTAL	4,742,091	4,740,561
Utility plant - net	4,000,153	3,980,991
Common shareholders' equity:
Paid in capital	597,592	597,467
Accumulated deficit	(19,019)	(25,191)
Total common shareholders' equity	578,573	572,276
Cumulative preferred stock of subsidiary	59,784	59,784
Long-term debt (Note 4)	2,479,192	2,477,538
Total capitalization	3,117,549	3,109,598
CURRENT LIABILITIES:
Short-term and current portion of long-term debt (Note 4)	165,000	148,000
Accounts payable	116,573	125,297
Accrued expenses	27,916	27,926
Accrued real estate and personal property taxes	23,780	18,145
Regulatory liabilities	715	2,532
Accrued Income Taxes, Current	340	0
Accrued interest	35,348	34,332
Customer deposits	31,343	31,306
Other current liabilities	10,313	10,392
Total current liabilities	411,328	397,930
DEFERRED CREDITS AND OTHER LONG-TERM LIABILITIES:
Regulatory liabilities	861,966	851,754
Deferred income taxes - net	246,627	245,257
Non-current income tax liability	4,620	4,651
Unamortized investment tax credit	727	954
Accrued pension and other postretirement benefits	18,888	50,070
Asset retirement obligations	79,459	79,535
Miscellaneous	927	812
Total deferred credits and other long-term liabilities	1,213,214	1,233,033
TOTAL	$ 4,742,091	$ 4,740,561

Unaudited Condensed Consolidat4

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable and unbilled revenue, allowance for doubtful accounts	$ 3,707	$ 2,830

Unaudited Condensed Consolidat5

Unaudited Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATIONS:
Net income	$ 32,303	$ 26,996
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	55,324	52,485
Amortization of redemption premiums and expense on debt	1,015	1,077
Deferred income taxes and investment tax credit adjustments - net	(3,293)	(6,509)
Allowance for equity funds used during construction	(5,102)	(6,425)
Change in certain assets and liabilities:
Accounts receivable	4,144	15,440
Fuel, materials and supplies	(1,290)	(4,721)
Increase (Decrease) in Income Taxes Payable	10,338	18,692
Income taxes receivable or payable	1,817	3,134
Accounts payable and accrued expenses	(15,315)	(12,343)
Accrued real estate and personal property taxes	5,635	4,614
Accrued interest	1,016	9,660
Accrued pension and other postretirement benefits	(31,181)	(10,135)
Short-term and long-term regulatory assets and liabilities	6,503	6,588
Prepaids and other current assets	(4,592)	(6,971)
Other - net	1,165	(3,306)
Net cash provided by operating activities	58,487	88,276
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures - utility	(47,452)	(64,298)
Project development costs	(161)	(333)
Cost of removal, net of salvage	(4,378)	(2,656)
Other	(86)	(395)
Net cash used in investing activities	(52,077)	(67,682)
CASH FLOWS FROM FINANCING ACTIVITIES:
Short-term debt borrowings	44,000	25,000
Short-term debt repayments	(27,000)	(15,000)
Dividends on common stock	(25,328)	(25,099)
Preferred dividends of subsidiary	(803)	(803)
Deferred financing costs paid	0	(107)
Payments for financed capital expenditures	(2,691)	(4,900)
Other	0	(228)
Net cash used in financing activities	(11,822)	(21,137)
Net change in cash and cash equivalents	(5,412)	(543)
Cash and cash equivalents at beginning of period	30,681	34,953
Cash and cash equivalents at end of period	25,269	34,410
Cash paid during the period for:
Interest (net of amount capitalized)	21,582	14,310
Non-cash investing activities:
Accruals for capital expenditures	$ 53,336	$ 21,983

Overview and Summary Of Signifi

Overview and Summary Of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
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 is owned by AES U.S. Investments ( 82.35% ) and CDPQ ( 17.65% ). 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 490,000 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. IPL’s largest generating station, Petersburg, is coal-fired. The second largest station, Harding Street, uses natural gas and fuel oil to power combustion turbines. In addition, IPL operates a 20 MW battery energy storage unit at this location, which provides frequency response. The third station, Eagle Valley, is a newly constructed 671 MW CCGT. IPL took operational control and commenced commercial operations of this CCGT in April 2018. The fourth station, Georgetown, is a small peaking station that uses natural gas to power combustion turbines. As of March 31, 2018 , IPL’s net electric generation capacity for winter is 2,996 MW and net summer capacity is 2,881 MW. Principles of Consolidation The accompanying Financial Statements include the accounts of IPALCO, IPL and Mid-America Capital Resources, Inc., a non-regulated wholly-owned subsidiary of IPALCO. All significant intercompany amounts have been eliminated. The accompanying Financial Statements are unaudited; however, they have been prepared in accordance with GAAP for interim financial information and in conjunction with the rules and regulations of the SEC. Accordingly, they do not include all of the disclosures required by GAAP for annual fiscal reporting periods. In the opinion of management, all adjustments of a normal recurring nature necessary for fair presentation have been included. The electric utility business is affected by seasonal weather patterns throughout the year and, therefore, the operating revenues and associated operating expenses are not generated evenly by month during the year. These unaudited Financial Statements have been prepared in accordance with the accounting policies described in IPALCO’s 2017 Form 10-K and should be read in conjunction therewith. 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 that management is required to make. Actual results may differ from those estimates. Reclassifications Certain immaterial amounts from prior periods have been reclassified to conform to the current year presentation. New Accounting Pronouncements Adopted in 2018 The following table provides a brief description of recent accounting pronouncements that had an impact on the Company’s Financial Statements. Accounting pronouncements not listed below were assessed and determined to be either not applicable or are expected to have no material impact on the Company’s Financial Statements. New Accounting Standards Adopted ASU Number and Name Description Date of Adoption Effect on the financial statements upon adoption 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost This standard changes the presentation of non-service costs associated with defined benefit plans and updates the guidance so that only the service cost component will be eligible for capitalization. Transition method: Retrospective for presentation of non-service cost expense. Prospective for the change in capitalization. January 1, 2018 The adoption of this standard resulted in a $(0.4) million reclassification of non-service pension costs (credits) from Other operating expenses to Miscellaneous income and (deductions) - net for the three months ended March 31, 2017. 2014-09, 2015-14, 2016-08, 2016-10, 2016-12, 2016-20, 2017-10, 2017-13, Revenue from Contracts with Customers (Topic 606) See discussion of the ASUs below. January 1, 2018 See impact upon adoption of the standard below. Adoption of ASC Topic 606, “ Revenue from Contracts with Customers ” On January 1, 2018, the Company adopted ASU 2014-09, “Revenue from Contracts with Customers”, and its subsequent corresponding updates (“ASC 606”). Under this standard, an entity shall recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company applied the modified retrospective method of adoption to those contracts that were not completed as of January 1, 2018. Results for reporting periods beginning January 1, 2018 are presented under ASC 606, while prior period amounts were not adjusted and continue to be reported in accordance with our historic accounting under the previous revenue recognition standard. For contracts that were modified before January 1, 2018, the Company reflected the aggregate effect of all modifications when identifying the satisfied and unsatisfied performance obligations, determining the transaction price and allocating the transaction price. There was no cumulative effect to our January 1, 2018 Condensed Consolidated Balance Sheet resulting from the adoption of ASC 606. New Accounting Pronouncements Issued But Not Yet Effective The following table provides a brief description of recent accounting pronouncements that could have a material impact on the Company’s Financial Statements. Accounting pronouncements not listed below were assessed and determined to be either not applicable or are expected to have no material impact on the Company’s Financial Statements. New Accounting Standards Issued But Not Yet Effective ASU Number and Name Description Date of Adoption Effect on the financial statements upon adoption 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities This standard shortens the period of amortization for the premium on certain callable debt securities to the earliest call date. Transition method: modified retrospective. January 1, 2019. Early adoption is permitted. The Company is currently evaluating the impact of adopting the standard on its consolidated financial statements. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments The standard updates the impairment model for financial assets measured at amortized cost. For trade and other receivables, held-to-maturity debt securities, loans and other instruments, entities will be required to use a new forward-looking “expected loss” model that generally will result in the earlier recognition of allowance for losses. For available-for-sale debt securities with unrealized losses, entities will measure credit losses as it is done today, except that the losses will be recognized as an allowance rather than a reduction in the amortized cost of the securities. Transition method: various. January 1, 2020 Early adoption is permitted only as of January 1, 2019. The Company is currently evaluating the impact of adopting the standard on its consolidated financial statements. 2016-02, 2018-01, Leases (Topic 842) See discussion of the ASUs below. January 1, 2019. Early adoption is permitted. The Company is currently evaluating the impact of adopting the standard on its consolidated financial statements. ASU 2016-02 and its subsequent corresponding updates require lessees to recognize assets and liabilities for most leases but recognize expenses in a manner similar to the current accounting methods. For lessors, the guidance modifies the lease classification criteria and the accounting for sales-type and direct financing leases. The guidance also eliminates the current real estate-specific provisions. The standard must be adopted using a modified retrospective approach at the beginning of the earliest comparative period presented in the financial statements (i.e., January 1, 2017). The FASB proposed amending the standard to give another option for transition. The proposed transition method would allow entities to not apply the new lease standard in the comparative periods presented in their financial statements in the year of adoption. Under the proposed transition method, the entity would apply the transition provisions on January 1, 2019 (i.e., the effective date). At transition, lessees and lessors are permitted to make an election to apply a package of practical expedients that allow them not to reassess: (1) whether any expired or existing contracts are or contain leases, (2) lease classification for any expired or existing leases, and (3) whether initial direct costs for any expired or existing leases qualify for capitalization under ASC 842. These three practical expedients must be elected as a package and must be consistently applied to all leases. Furthermore, entities are also permitted to make an election to use hindsight when determining lease term and lessees can elect to use hindsight when assessing the impairment of right-of-use assets. The Company has established a task force focused on the identification of contracts that would be under the scope of the new standard and on the assessment and measurement of the right-of-use asset and related liability. Additionally, the implementation team has been working on the configuration of a lease accounting system that will support the implementation and the subsequent accounting. The implementation team is in the process of evaluating changes to our business processes, systems and controls to support recognition and disclosure under the new standard. As the Company has preliminarily concluded that at transition it would be using the package of practical expedients, the main impact expected as of the effective date is the recognition of the right to use asset and the related liability in the financial statements for all those contracts that contain a lease and for which the Company is the lessee. However, income statement presentation and the expense recognition pattern will not change. Under ASC 842, it is expected that fewer contracts will contain a lease. However, due to the elimination of today's real estate-specific guidance and changes to certain lessor classification criteria, more leases will qualify as sales-type leases and direct financing leases. Under these two models, a lessor will derecognize the asset and will recognize a lease receivable. According to ASC 842, the lease receivable does not include variable payments that depend on the use of the asset (e.g. MWh produced by a facility). Therefore, the lease receivable could be lower than the carrying amount of the underlying asset at lease commencement. In such circumstances, the difference between the initially recognized lease receivable and the carrying amount of the underlying asset is recognized as a selling loss at lease commencement. The Company is assessing situations for which this guidance would apply.

Regulatory Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2018
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS Basic Rates and Charges In May 2014, IPL received an order from the IURC granting approval to build a 644 to 685 MW CCGT at Eagle Valley. The costs to build and operate the CCGT, other than fuel costs, will not be recoverable by IPL through rates until the conclusion of a base rate case proceeding with the IURC after construction is completed. IPL filed a petition with the IURC on December 21, 2017, for authority to increase its basic rates and charges to coincide with the completion of the CCGT in the first half of 2018. IPL’s proposed revenue increase was $124.5 million annually, or 9.1% . On February 16, 2018, IPL filed an update to such petition to reflect the federal income tax law changes passed, which reduced the revenue increase IPL is seeking to $96.7 million , or 7.1% . We expect an order on this proceeding to be issued by the IURC by the first quarter of 2019. DSM On February 7, 2018, the IURC approved a settlement agreement establishing a new three year DSM plan for IPL through 2020. The approval included cost recovery of programs as well as performance incentives, depending on the level of success of the programs. The order also approved recovery of lost revenues, consistent with the provisions of the settlement agreement. Taxes On January 3, 2018, the IURC opened a generic investigation to review and consider the impacts from the TCJA and how any resulting benefits should be realized by customers. The IURC’s order opening this investigation directed Indiana utilities to apply regulatory accounting treatment, such as the use of regulatory assets and regulatory liabilities, for all estimated impacts resulting from the TCJA. On February 16, 2018, the IURC issued an order establishing two phases of the investigation. The first phase (“Phase I”) directs respondent utilities (including IPL) to make a filing to remove from respondents’ rates and charges for service, the impact of a lower federal income tax rate. The second phase (“Phase II”) was established to address remaining issues from the TCJA, including treatment of deferred taxes and how these benefits will be realized by customers. On March 5, 2018, IPL filed a motion to be dismissed from the generic investigation and to address these matters in its pending general rate case. The IURC approved IPL’s request with regard to Phase II issues, but denied the request for Phase I. On March 26, 2018, IPL complied with Phase I by filing a request for a subdocket to address the issues in Phase I of the investigation. The subdocket was granted on April 13, 2018, and IPL’s case-in-chief was filed on April 23, 2018. The ultimate result of these issues cannot be determined at this time, although it could be material.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE Fair Value Hierarchy 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. As of March 31, 2018 and December 31, 2017 , all of IPALCO’s financial assets or liabilities adjusted to fair value on a recurring basis (excluding pension assets – see Note 6, “ Benefit Plans ”) were considered Level 3, based on the above fair value hierarchy. These primarily consisted of FTRs, which are used to offset MISO congestion charges. Because the benefit associated with FTRs is a flow-through to IPL’s customers, IPL records a regulatory liability matching the value of the FTRs. These financial assets and liabilities were not material to the Financial Statements in the periods covered by this report, individually or in the aggregate. 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. 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 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 March 31, 2018 and December 31, 2017 , ARO liabilities were $79.5 million and $79.5 million , respectively. 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: March 31, 2018 December 31, 2017 Face Value Fair Value Face Value Fair Value (In Thousands) Fixed-rate $ 2,418,800 $ 2,576,300 $ 2,418,800 $ 2,655,000 Variable-rate 255,000 255,000 238,000 238,000 Total indebtedness $ 2,673,800 $ 2,831,300 $ 2,656,800 $ 2,893,000 The difference between the face value and the carrying value of this indebtedness represents the following: • unamortized deferred financing costs of $22.8 million and $24.4 million at March 31, 2018 and December 31, 2017 , respectively; and • unamortized discounts of $6.8 million and $6.9 million at March 31, 2018 and December 31, 2017 , respectively.

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Indebtedness	DEBT Long-Term Debt The following table presents our long-term debt: March 31, December 31, Series Due 2018 2017 (In Thousands) IPL first mortgage bonds: 3.875% (1) August 2021 $ 55,000 $ 55,000 3.875% (1) August 2021 40,000 40,000 3.125% (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 260,000 260,000 4.05% May 2046 350,000 350,000 Unamortized discount – net (6,321 ) (6,353 ) Deferred financing costs (16,039 ) (16,168 ) Total IPL first mortgage bonds 1,586,440 1,586,279 IPL unsecured debt: Variable (2) December 2020 30,000 30,000 Variable (2) December 2020 60,000 60,000 Deferred financing costs (315 ) (344 ) Total IPL unsecured debt 89,685 89,656 Total Long-term Debt – IPL 1,676,125 1,675,935 Long-term Debt – IPALCO: 3.45% Senior Secured Notes July 2020 405,000 405,000 3.70% Senior Secured Notes September 2024 405,000 405,000 Unamortized discount – net (506 ) (534 ) Deferred financing costs (6,427 ) (7,863 ) Total Long-term Debt – IPALCO 803,067 801,603 Total Consolidated IPALCO Long-term Debt $ 2,479,192 $ 2,477,538 (1) First mortgage bonds issued to the Indiana Finance Authority, to secure the loan of proceeds from tax-exempt bonds issued by the Indiana Finance Authority. (2) Unsecured notes 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. These notes were issued in two series: $30 million Series 2015A notes and $60 million 2015B notes. The notes have a final maturity date of December 2038, but are subject to a mandatory put in December 2020. IPALCO’s Senior Secured Notes On November 13, 2017, IPALCO filed with the SEC a registration statement on Form S-4 with respect to an exchange of registered notes for its previously unregistered 2024 IPALCO Notes. This registration statement was declared effective on December 5, 2017, and the exchange offer was completed on January 12, 2018. Line of Credit As of March 31, 2018 and December 31, 2017 , IPL had $165.0 million and $148.0 million in outstanding borrowings on the committed line of credit, respectively.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES U.S. Tax Reform On December 22, 2017, the U.S. federal government enacted the TCJA. The TCJA significantly changes U.S. corporate income tax law. Notable items impacting the effective tax rate for the 2018 tax year related to the TCJA include a rate reduction in the corporate tax rate to 21% from 35% and an increase in the estimated flow-through depreciation partially offset by the repeal of the manufacturer’s production deduction. Effective Tax Rate IPALCO’s effective combined state and federal income tax rate was 18.3% for the three months ended March 31, 2018 , as compared to 31.8% for the three months ended March 31, 2017 . The decrease in the effective tax rate versus the comparable period was primarily due to the impact of the TCJA (as explained above).

Benefit Plans

Benefit Plans	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Benefit Plans	BENEFIT PLANS The following table (in thousands) presents information for the three months ended March 31, 2018 , relating to the Pension Plans: Net unfunded status of plans: Net unfunded status at December 31, 2017, before tax adjustments $ (43,161 ) Net benefit cost components reflected in net unfunded status during first quarter: Service cost (2,113 ) Interest cost (6,305 ) Expected return on assets 10,200 Curtailment (1) (449 ) Employer contributions 30,000 Net unfunded status at March 31, 2018, before tax adjustments $ (11,828 ) Regulatory assets related to pensions (2) : Regulatory assets at December 31, 2017, before tax adjustments $ 211,125 Amount reclassified through net benefit cost: Amortization of prior service cost (959 ) Amortization of net actuarial loss (2,851 ) Curtailment (1) (781 ) Regulatory assets at March 31, 2018, before tax adjustments $ 206,534 (1) As a result of the recently announced AES restructuring, we recognized a plan curtailment of $1.2 million for the three months ended March 31, 2018. (2) Amounts that would otherwise be charged/credited to Accumulated Other Comprehensive Income or Loss upon application of ASC 715, “Compensation – Retirement Benefits,” are recorded as a regulatory asset or liability because IPL has historically recovered and currently recovers pension and other postretirement benefit expenses in rates. These are unrecognized amounts not yet recognized as components of net periodic benefit costs. Pension Expense The following table presents net periodic benefit cost information relating to the Pension Plans combined: For the Three Months Ended, March 31, 2018 2017 (In Thousands) Components of net periodic benefit cost: Service cost $ 2,113 $ 1,836 Interest cost 6,305 6,327 Expected return on plan assets (10,200 ) (11,167 ) Amortization of prior service cost 959 1,060 Amortization of actuarial loss 2,851 3,300 Curtailments and settlements (1) 1,230 146 Net periodic benefit cost $ 3,258 $ 1,502 (1) As a result of the recently announced AES restructuring, we recognized a plan curtailment of $1.2 million for the three months ended March 31, 2018. The settlement loss of $0.1 million for the three months ended March 31, 2017 was the result of a lump sum distribution paid out of the Supplemental Retirement Plan. In addition, IPL provides postretirement health care benefits to certain active or retired employees and the spouses of certain active or retired employees. These postretirement health care benefits and the related unfunded obligation of $7.1 million and $7.0 million at March 31, 2018 and December 31, 2017 , respectively, were not material to the Financial Statements in the periods covered by this report.

Commitments And Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
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 the 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 and Other CAA NOVs In October 2009, IPL received a NOV and Finding of Violation from the EPA pursuant to the CAA Section 113(a). The NOV alleges violations of the CAA at IPL’s three primarily coal-fired electric generating facilities at the time, dating back to 1986. The alleged violations primarily pertain to the PSD and nonattainment New Source Review requirements under the CAA. In addition, on October 1, 2015, IPL received a NOV from the EPA pursuant to CAA Section 113(a) alleging violations of the CAA, the Indiana SIP, and the Title V operating permit related to alleged particulate matter and opacity violations at IPL Petersburg Unit 3. Also, on February 5, 2016, the EPA issued a NOV pursuant to CAA Section 113(a) alleging violations of New Source Review and other CAA regulations, the Indiana SIP, and the Title V operating permit at Petersburg Generating Station. Since receiving the letters, IPL management has met with the EPA staff regarding possible resolutions of the NOVs. Settlements and litigated outcomes of similar New Source Review 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 these cases could have a material impact on our business. At this time, we cannot determine whether these NOVs could have a material impact on our business, financial condition or results of operations. 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 these New Source Review cases and other CAA NOV matters.

Business Segment Information (N

Business Segment Information (Notes)	3 Months Ended
	Mar. 31, 2018
Segment Reporting Information [Line Items]
Segment Reporting Disclosure [Text Block]	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 nonutility business activities aggregated separately. The “All Other” nonutility category primarily includes the 2020 IPALCO Notes and the 2024 IPALCO Notes; approximately $4.6 million and $18.3 million of cash and cash equivalents as of March 31, 2018 and December 31, 2017 , respectively; long-term investments of $4.0 million and $5.1 million at March 31, 2018 and December 31, 2017 , respectively; and income taxes and interest related to those items. All other assets represented less than 1% of IPALCO’s total assets as of March 31, 2018 and December 31, 2017 . 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 thousands): Three Months Ended Three Months Ended March 31, 2018 March 31, 2017 Utility All Other Total Utility All Other Total Operating revenues $ 354,504 $ — $ 354,504 $ 336,909 $ — $ 336,909 Income taxes $ 9,056 $ (2,011 ) $ 7,045 $ 15,724 $ (3,541 ) $ 12,183 Interest and other charges - net $ 16,068 $ 7,700 $ 23,768 $ 16,073 $ 9,010 $ 25,083 Net income $ 38,108 $ (5,805 ) $ 32,303 $ 32,270 $ (5,274 ) $ 26,996 As of March 31, 2018 As of December 31, 2017 Utility All Other Total Utility All Other Total Total assets $ 4,733,584 $ 8,507 $ 4,742,091 $ 4,719,547 $ 21,014 $ 4,740,561

Revenue (Notes)

Revenue (Notes)	3 Months Ended
	Mar. 31, 2018
Revenue from External Customer [Line Items]
Revenue from Contract with Customer [Text Block]	REVENUE Revenue is primarily earned from retail and wholesale electricity sales and electricity transmission and distribution delivery services. Revenue is recognized upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. Revenue is recorded net of any taxes assessed on and collected from customers, which are remitted to the governmental authorities. Retail revenues - IPL energy sales to utility customers are based on the reading of meters at the customer’s location that occurs on a systematic basis throughout the month. IPL sells electricity directly to end-users, such as homes and businesses, and bills customers directly. Retail revenues have a single performance obligation, as the promise to transfer energy and other distribution and/or transmission services are not separately identifiable from other promises in the contracts and, therefore, are not distinct. Additionally, as the performance obligation is satisfied over time as energy is delivered, and the same method is used to measure progress, the performance obligation meets the criteria to be considered a series. In exchange for the exclusive right to sell or distribute electricity in our service area, IPL is subject to rate regulation by federal and state regulators. This regulation sets the framework for the prices (“tariffs”) that IPL is allowed to charge customers for electric services. Since tariffs are approved by the regulator, the price that IPL has the right to bill corresponds directly with the value to the customer of IPL’s performance completed in each period. Therefore, revenue under these contracts is recognized using an output method measured by the MWhs delivered each month at the approved tariff. Customer payments are typically due on a monthly basis. Wholesale revenues - Power produced at the generation stations in excess of our retail load is required to be sold into the MISO market at either the day-ahead or real time hourly market price, and these sales are classified as wholesale revenues. We sell to and purchase power from MISO, and such sales and purchases are settled and accounted for on a net hourly basis. In the MISO market, wholesale revenue is recorded at the spot price based on the quantities of MWh delivered in each day or hour during each month. As a member of MISO, we are obligated to declare the availability of our energy production into the wholesale energy market, but we are not obligated to commit our previously declared availability. As such, contract terms end as the energy for each day is delivered to the market in the case of the day-ahead market and for each hour in the case of the real-time market. Miscellaneous revenues - Miscellaneous revenues are mainly comprised of MISO transmission revenues. MISO transmission revenues are earned when IPL’s power lines are used in transmission of energy by power producers other than IPL. As IPL owns and operates transmission lines in central Indiana, demand charges collected from network customers by MISO are allocated to the appropriate transmission owners (including IPL) and recognized as transmission revenues. Transmission revenues have a single performance obligation, as transmission services represent a distinct service. Additionally, as the performance obligation is satisfied over time and the same method is used to measure progress, the performance obligation meets the criteria to be considered a series. The price that the transmission operator has the right to bill corresponds directly with the value to the customer of IPL’s performance completed in each period as the price paid is the transmission operators allocation of the tariff rate (as approved by the regulator) charged to network participants. IPL’s revenue from contracts with customers was $352.3 million for the three months ended March 31, 2018. The following table presents our revenue from contracts with customers and other revenue during the three months ended March 31, 2018 (in thousands): Utility Retail Revenues Retail revenue from contracts with customers $ 348,500 Other retail revenues (1) 919 Wholesale Revenues 1,510 Miscellaneous Revenues Transmission and other revenue from contracts with customers 2,243 Other miscellaneous revenues (2) 1,332 Total Revenues $ 354,504 (1) Other retail revenue represents alternative revenue programs not accounted for under ASC 606 (2) Other miscellaneous revenue includes lease and other miscellaneous revenues not accounted for under ASC 606 The balances of receivables from contracts with customers are $152.9 million and $155.7 million as of March 31, 2018 and January 1, 2018, respectively. Payment terms for all receivables from contracts with customers are typically within 30 days. The Company has elected to apply the optional disclosure exemptions under ASC 606. Therefore, the Company has not included disclosure pertaining to revenue expected to be recognized in any future year related to remaining performance obligations, as we exclude contracts with an original length of one year or less, contracts for which we recognize revenue based on the amount we have the right to invoice for services performed, and contracts with variable consideration allocated entirely to a wholly unsatisfied performance obligation when the consideration relates specifically to our efforts to satisfy the performance obligation and depicts the amount to which we expect to be entitled.

Overview and Summary Of Signi15

Overview and Summary Of Significant Accounting Policies (Policy)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The accompanying Financial Statements include the accounts of IPALCO, IPL and Mid-America Capital Resources, Inc., a non-regulated wholly-owned subsidiary of IPALCO. All significant intercompany amounts have been eliminated. The accompanying Financial Statements are unaudited; however, they have been prepared in accordance with GAAP for interim financial information and in conjunction with the rules and regulations of the SEC. Accordingly, they do not include all of the disclosures required by GAAP for annual fiscal reporting periods. In the opinion of management, all adjustments of a normal recurring nature necessary for fair presentation have been included. The electric utility business is affected by seasonal weather patterns throughout the year and, therefore, the operating revenues and associated operating expenses are not generated evenly by month during the year. These unaudited Financial Statements have been prepared in accordance with the accounting policies described in IPALCO’s 2017 Form 10-K and should be read in conjunction therewith.
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 that management is required to make. Actual results may differ from those estimates.
Reclassifications	Reclassifications Certain immaterial amounts from prior periods have been reclassified to conform to the current year presentation.
New Accounting Pronouncements	New Accounting Pronouncements Adopted in 2018 The following table provides a brief description of recent accounting pronouncements that had an impact on the Company’s Financial Statements. Accounting pronouncements not listed below were assessed and determined to be either not applicable or are expected to have no material impact on the Company’s Financial Statements. New Accounting Standards Adopted ASU Number and Name Description Date of Adoption Effect on the financial statements upon adoption 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost This standard changes the presentation of non-service costs associated with defined benefit plans and updates the guidance so that only the service cost component will be eligible for capitalization. Transition method: Retrospective for presentation of non-service cost expense. Prospective for the change in capitalization. January 1, 2018 The adoption of this standard resulted in a $(0.4) million reclassification of non-service pension costs (credits) from Other operating expenses to Miscellaneous income and (deductions) - net for the three months ended March 31, 2017. 2014-09, 2015-14, 2016-08, 2016-10, 2016-12, 2016-20, 2017-10, 2017-13, Revenue from Contracts with Customers (Topic 606) See discussion of the ASUs below. January 1, 2018 See impact upon adoption of the standard below. Adoption of ASC Topic 606, “ Revenue from Contracts with Customers ” On January 1, 2018, the Company adopted ASU 2014-09, “Revenue from Contracts with Customers”, and its subsequent corresponding updates (“ASC 606”). Under this standard, an entity shall recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company applied the modified retrospective method of adoption to those contracts that were not completed as of January 1, 2018. Results for reporting periods beginning January 1, 2018 are presented under ASC 606, while prior period amounts were not adjusted and continue to be reported in accordance with our historic accounting under the previous revenue recognition standard. For contracts that were modified before January 1, 2018, the Company reflected the aggregate effect of all modifications when identifying the satisfied and unsatisfied performance obligations, determining the transaction price and allocating the transaction price. There was no cumulative effect to our January 1, 2018 Condensed Consolidated Balance Sheet resulting from the adoption of ASC 606. New Accounting Pronouncements Issued But Not Yet Effective The following table provides a brief description of recent accounting pronouncements that could have a material impact on the Company’s Financial Statements. Accounting pronouncements not listed below were assessed and determined to be either not applicable or are expected to have no material impact on the Company’s Financial Statements. New Accounting Standards Issued But Not Yet Effective ASU Number and Name Description Date of Adoption Effect on the financial statements upon adoption 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities This standard shortens the period of amortization for the premium on certain callable debt securities to the earliest call date. Transition method: modified retrospective. January 1, 2019. Early adoption is permitted. The Company is currently evaluating the impact of adopting the standard on its consolidated financial statements. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments The standard updates the impairment model for financial assets measured at amortized cost. For trade and other receivables, held-to-maturity debt securities, loans and other instruments, entities will be required to use a new forward-looking “expected loss” model that generally will result in the earlier recognition of allowance for losses. For available-for-sale debt securities with unrealized losses, entities will measure credit losses as it is done today, except that the losses will be recognized as an allowance rather than a reduction in the amortized cost of the securities. Transition method: various. January 1, 2020 Early adoption is permitted only as of January 1, 2019. The Company is currently evaluating the impact of adopting the standard on its consolidated financial statements. 2016-02, 2018-01, Leases (Topic 842) See discussion of the ASUs below. January 1, 2019. Early adoption is permitted. The Company is currently evaluating the impact of adopting the standard on its consolidated financial statements. ASU 2016-02 and its subsequent corresponding updates require lessees to recognize assets and liabilities for most leases but recognize expenses in a manner similar to the current accounting methods. For lessors, the guidance modifies the lease classification criteria and the accounting for sales-type and direct financing leases. The guidance also eliminates the current real estate-specific provisions. The standard must be adopted using a modified retrospective approach at the beginning of the earliest comparative period presented in the financial statements (i.e., January 1, 2017). The FASB proposed amending the standard to give another option for transition. The proposed transition method would allow entities to not apply the new lease standard in the comparative periods presented in their financial statements in the year of adoption. Under the proposed transition method, the entity would apply the transition provisions on January 1, 2019 (i.e., the effective date). At transition, lessees and lessors are permitted to make an election to apply a package of practical expedients that allow them not to reassess: (1) whether any expired or existing contracts are or contain leases, (2) lease classification for any expired or existing leases, and (3) whether initial direct costs for any expired or existing leases qualify for capitalization under ASC 842. These three practical expedients must be elected as a package and must be consistently applied to all leases. Furthermore, entities are also permitted to make an election to use hindsight when determining lease term and lessees can elect to use hindsight when assessing the impairment of right-of-use assets. The Company has established a task force focused on the identification of contracts that would be under the scope of the new standard and on the assessment and measurement of the right-of-use asset and related liability. Additionally, the implementation team has been working on the configuration of a lease accounting system that will support the implementation and the subsequent accounting. The implementation team is in the process of evaluating changes to our business processes, systems and controls to support recognition and disclosure under the new standard. As the Company has preliminarily concluded that at transition it would be using the package of practical expedients, the main impact expected as of the effective date is the recognition of the right to use asset and the related liability in the financial statements for all those contracts that contain a lease and for which the Company is the lessee. However, income statement presentation and the expense recognition pattern will not change. Under ASC 842, it is expected that fewer contracts will contain a lease. However, due to the elimination of today's real estate-specific guidance and changes to certain lessor classification criteria, more leases will qualify as sales-type leases and direct financing leases. Under these two models, a lessor will derecognize the asset and will recognize a lease receivable. According to ASC 842, the lease receivable does not include variable payments that depend on the use of the asset (e.g. MWh produced by a facility). Therefore, the lease receivable could be lower than the carrying amount of the underlying asset at lease commencement. In such circumstances, the difference between the initially recognized lease receivable and the carrying amount of the underlying asset is recognized as a selling loss at lease commencement. The Company is assessing situations for which this guidance would apply.

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
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: March 31, 2018 December 31, 2017 Face Value Fair Value Face Value Fair Value (In Thousands) Fixed-rate $ 2,418,800 $ 2,576,300 $ 2,418,800 $ 2,655,000 Variable-rate 255,000 255,000 238,000 238,000 Total indebtedness $ 2,673,800 $ 2,831,300 $ 2,656,800 $ 2,893,000

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule Long-Term Indebtedness	The following table presents our long-term debt: March 31, December 31, Series Due 2018 2017 (In Thousands) IPL first mortgage bonds: 3.875% (1) August 2021 $ 55,000 $ 55,000 3.875% (1) August 2021 40,000 40,000 3.125% (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 260,000 260,000 4.05% May 2046 350,000 350,000 Unamortized discount – net (6,321 ) (6,353 ) Deferred financing costs (16,039 ) (16,168 ) Total IPL first mortgage bonds 1,586,440 1,586,279 IPL unsecured debt: Variable (2) December 2020 30,000 30,000 Variable (2) December 2020 60,000 60,000 Deferred financing costs (315 ) (344 ) Total IPL unsecured debt 89,685 89,656 Total Long-term Debt – IPL 1,676,125 1,675,935 Long-term Debt – IPALCO: 3.45% Senior Secured Notes July 2020 405,000 405,000 3.70% Senior Secured Notes September 2024 405,000 405,000 Unamortized discount – net (506 ) (534 ) Deferred financing costs (6,427 ) (7,863 ) Total Long-term Debt – IPALCO 803,067 801,603 Total Consolidated IPALCO Long-term Debt $ 2,479,192 $ 2,477,538 (1) First mortgage bonds issued to the Indiana Finance Authority, to secure the loan of proceeds from tax-exempt bonds issued by the Indiana Finance Authority. (2) Unsecured notes 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. These notes were issued in two series: $30 million Series 2015A notes and $60 million 2015B notes. The notes have a final maturity date of December 2038, but are subject to a mandatory put in December 2020.

Benefit Plans (Tables)

Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Schedule Of Defined Benefit Plans Disclosures	The following table (in thousands) presents information for the three months ended March 31, 2018 , relating to the Pension Plans: Net unfunded status of plans: Net unfunded status at December 31, 2017, before tax adjustments $ (43,161 ) Net benefit cost components reflected in net unfunded status during first quarter: Service cost (2,113 ) Interest cost (6,305 ) Expected return on assets 10,200 Curtailment (1) (449 ) Employer contributions 30,000 Net unfunded status at March 31, 2018, before tax adjustments $ (11,828 ) Regulatory assets related to pensions (2) : Regulatory assets at December 31, 2017, before tax adjustments $ 211,125 Amount reclassified through net benefit cost: Amortization of prior service cost (959 ) Amortization of net actuarial loss (2,851 ) Curtailment (1) (781 ) Regulatory assets at March 31, 2018, before tax adjustments $ 206,534 (1) As a result of the recently announced AES restructuring, we recognized a plan curtailment of $1.2 million for the three months ended March 31, 2018. (2) Amounts that would otherwise be charged/credited to Accumulated Other Comprehensive Income or Loss upon application of ASC 715, “Compensation – Retirement Benefits,” are recorded as a regulatory asset or liability because IPL has historically recovered and currently recovers pension and other postretirement benefit expenses in rates. These are unrecognized amounts not yet recognized as components of net periodic benefit costs.
Schedule Of Net Periodic Benefit Costs	The following table presents net periodic benefit cost information relating to the Pension Plans combined: For the Three Months Ended, March 31, 2018 2017 (In Thousands) Components of net periodic benefit cost: Service cost $ 2,113 $ 1,836 Interest cost 6,305 6,327 Expected return on plan assets (10,200 ) (11,167 ) Amortization of prior service cost 959 1,060 Amortization of actuarial loss 2,851 3,300 Curtailments and settlements (1) 1,230 146 Net periodic benefit cost $ 3,258 $ 1,502

Business Segment Information (T

Business Segment Information (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting Information [Line Items]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	The following table provides information about IPALCO’s business segments (in thousands): Three Months Ended Three Months Ended March 31, 2018 March 31, 2017 Utility All Other Total Utility All Other Total Operating revenues $ 354,504 $ — $ 354,504 $ 336,909 $ — $ 336,909 Income taxes $ 9,056 $ (2,011 ) $ 7,045 $ 15,724 $ (3,541 ) $ 12,183 Interest and other charges - net $ 16,068 $ 7,700 $ 23,768 $ 16,073 $ 9,010 $ 25,083 Net income $ 38,108 $ (5,805 ) $ 32,303 $ 32,270 $ (5,274 ) $ 26,996 As of March 31, 2018 As of December 31, 2017 Utility All Other Total Utility All Other Total Total assets $ 4,733,584 $ 8,507 $ 4,742,091 $ 4,719,547 $ 21,014 $ 4,740,561

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Table Text Block]	The following table presents our revenue from contracts with customers and other revenue during the three months ended March 31, 2018 (in thousands): Utility Retail Revenues Retail revenue from contracts with customers $ 348,500 Other retail revenues (1) 919 Wholesale Revenues 1,510 Miscellaneous Revenues Transmission and other revenue from contracts with customers 2,243 Other miscellaneous revenues (2) 1,332 Total Revenues $ 354,504 (1) Other retail revenue represents alternative revenue programs not accounted for under ASC 606 (2) Other miscellaneous revenue includes lease and other miscellaneous revenues not accounted for under ASC 606

Overview and Summary of Signi21

Overview and Summary of Significant Accounting Policies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)generating_stationmiMW	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Number of customers	490,000
Distance of furthest customer from Indianapolis | mi	40
Number of generating stations | generating_station	4
Deferred financing costs | $	$ 22.8	$ 24.4
Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Electric generation capability for winter, megawatts	2,996
Electric generation capability for summer, megawatts	2,881
Aes U.S. Investments [Member]
Debt Instrument [Line Items]
Ownership percentage by parent (percent)	82.35%
CDPQ [Member]
Debt Instrument [Line Items]
Ownership percentage by parent (percent)	17.65%
Ownership interest in parent company (percent)	15.00%
AES U.S. Holdings, LLC [Member]
Debt Instrument [Line Items]
Ownership interest in parent company (percent)	85.00%
Harding Street [Member]
Debt Instrument [Line Items]
Amount of New Operation for Battery Storage Unit, megawatts	20
Eagle Valley [Member]
Debt Instrument [Line Items]
Expected CCGT Output, megawatts	671

Regulatory Matters (Details)

Regulatory Matters (Details) $ in Thousands	Feb. 16, 2018USD ($)	Dec. 21, 2017USD ($)	May 31, 2014MW	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Regulatory Matters [Line Items]
Total current regulatory assets				$ 38,433	$ 35,341
Total long-term regulatory assets				375,264	378,904
Total current regulatory liabilities				715	2,532
Total long-term regulatory liabilities				$ 861,966	$ 851,754
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 124,500
Public Utilities, Requested Rate Increase (Decrease), Percentage		9.10%
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	$ 96,700
Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage	7.10%
Eagle Valley [Member]
Regulatory Matters [Line Items]
Public Utilities, Approved Production Plant Capacity, Minimum | MW			644
Public Utilities, Approved Production Plan Capacity , Maximum | MW			685

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Asset retirement obligations	$ 79,459	$ 79,535
Unamortized deferred financing costs	22,800	24,400
Unamortized debt discount	$ 6,800	$ 6,900

Fair Value (Schedule Of Face An

Fair Value (Schedule Of Face And Fair Value Of Debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Face Value	$ 2,673,800	$ 2,656,800
Fair Value	2,831,300	2,893,000
Fixed Rate [Member]
Debt Instrument [Line Items]
Face Value	2,418,800	2,418,800
Fair Value	2,576,300	2,655,000
Variable Rate [Member]
Debt Instrument [Line Items]
Face Value	255,000	238,000
Fair Value	$ 255,000	$ 238,000

Debt (Schedule Long-Term Indebt

Debt (Schedule Long-Term Indebtedness) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unamortized discount - net	$ (6,800)	$ (6,900)
Deferred financing costs	(22,800)	(24,400)
Long-term debt	2,479,192	2,477,538
Net Consolidated IPALCO Long-term Debt	2,479,192	2,477,538
Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
First mortgage bonds	1,586,440	1,586,279
Unamortized discount - net	(6,321)	(6,353)
Long-term debt	1,676,125	1,675,935
Unsecured Debt	$ 89,685	89,656
Indianapolis Power And Light Company [Member] | First Mortgage Bond 3.875% Due August 2021 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	3.875%
Debt due date	Aug. 1, 2021
First mortgage bonds	$ 55,000	55,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 3.875% Due August 2021 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	3.875%
Debt due date	Aug. 1, 2021
First mortgage bonds	$ 40,000	40,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.55% Due December 2024 [Member]
Debt Instrument [Line Items]
Debt due date	Dec. 1, 2024
First mortgage bonds	$ 40,000	40,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.60% Due January 2034 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	6.60%
Debt due date	Jan. 1, 2034
First mortgage bonds	$ 100,000	100,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.05% Due October 2036 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	6.05%
Debt due date	Oct. 1, 2036
First mortgage bonds	$ 158,800	158,800
Indianapolis Power And Light Company [Member] | First Mortgage Bond 6.60% Due June 2037 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	6.60%
Debt due date	Jun. 1, 2037
First mortgage bonds	$ 165,000	165,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.875% Due November 2041 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	4.875%
Debt due date	Nov. 1, 2041
First mortgage bonds	$ 140,000	140,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.65% Due June 2043 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	4.65%
Debt due date	Jun. 1, 2043
First mortgage bonds	$ 170,000	170,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.50% Due June 2044[Member]
Debt Instrument [Line Items]
Debt, stated interest rate	4.50%
Debt due date	Jun. 1, 2044
First mortgage bonds	$ 130,000	130,000
Indianapolis Power And Light Company [Member] | First Mortgage Bond 4.70%, Due September 2045 [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	4.70%
Debt due date	Sep. 1, 2045
First mortgage bonds	$ 260,000	260,000
Indianapolis Power And Light Company [Member] | FMB Twenty [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	4.05%
Debt due date	May 1, 2046
First mortgage bonds	$ 350,000	350,000
Indianapolis Power And Light Company [Member] | Environmental Facilities Refunding Revenue Notes, Series 2015A [Member]
Debt Instrument [Line Items]
Debt due date	Dec. 22, 2020
Unsecured Debt	$ 30,000	30,000
Indianapolis Power And Light Company [Member] | Environmental Facilities Refunding Revenue Notes, Series 2015B [Member]
Debt Instrument [Line Items]
Debt due date	Dec. 22, 2020
Unsecured Debt	$ 60,000	60,000
Ipalco Enterprises, Inc. [Member]
Debt Instrument [Line Items]
Unamortized discount - net	(506)	(534)
Deferred financing costs	(6,427)	(7,863)
Net Consolidated IPALCO Long-term Debt	$ 803,067	801,603
Ipalco Enterprises, Inc. [Member] | 3.45% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Debt due date	Jul. 1, 2020
Long-term debt	$ 405,000	405,000
Ipalco Enterprises, Inc. [Member] | Three Point Seven Zero Percent Senior Secured Notes [Domain]
Debt Instrument [Line Items]
Debt due date	Sep. 1, 2024
Long-term debt	$ 405,000	405,000
First Mortgage Bonds [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Deferred financing costs	(16,039)	(16,168)
Unsecured Debt [Member] | Indianapolis Power And Light Company [Member]
Debt Instrument [Line Items]
Deferred financing costs	$ (315)	$ (344)

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term Debt	$ 2,479,192	$ 2,477,538
Line of credit, outstanding borrowings	165,000	148,000
Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term Debt	1,676,125	1,675,935
Secured Debt	1,586,440	1,586,279
Parent Company [Member] | Three Point Seven Zero Percent Senior Secured Notes [Domain]
Debt Instrument [Line Items]
Long-term Debt	$ 405,000	$ 405,000
Debt instrument, maturity date	Sep. 1, 2024

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation Tax Cuts and Jobs Act of 2017 Percent			21.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%
State and federal income tax rate	18.30%	31.80%

Benefit Plans (Narrative) (Deta

Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Postretirement Health Care Benefits [Member] | Subsidiaries [Member]
Defined Benefit Plan Disclosure [Line Items]
Unfunded obligation	$ 7.1	$ 7

Benefit Plans (Schedule Of Defi

Benefit Plans (Schedule Of Defined Benefit Plans Disclosures) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Unfunded Status of Plans [Roll Forward]
Net funded status before tax adjustments	$ (43,161)
Service cost	(2,113)	$ (1,836)
Interest cost	(6,305)	(6,327)
Expected return on assets	10,200	11,167
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	449
Employer contributions	30,000
Net funded status before tax adjustments	(11,828)
Regulatory Assets Related to Pensions [Roll Forward]
Amortization of prior service cost	(959)	(1,060)
Defined Benefit Plan, Amortization of Gain (Loss)	(2,851)	(3,300)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	1,230	$ 146
Pension Plan [Member]
Net Unfunded Status of Plans [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(781)
Regulatory Assets Related to Pensions [Roll Forward]
Regulatory assets before tax adjustments	211,125
Amortization of prior service cost	(959)
Regulatory assets before tax adjustments	206,534
Defined Benefit Plan, Amortization of Gain (Loss)	$ (2,851)

Benefit Plans (Schedule Of Net

Benefit Plans (Schedule Of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Retirement Benefits [Abstract]
Service cost	$ 2,113	$ 1,836
Interest cost	6,305	6,327
Expected return on assets	(10,200)	(11,167)
Amortization of prior service cost	959	1,060
Amortization of actuarial loss	2,851	3,300
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement	1,230	146
Net periodic benefit cost	$ 3,258	$ 1,502

Commitments and Contingencies (

Commitments and Contingencies (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

Business Segment Information (D

Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Electric Revenue	$ 354,504	$ 336,909
Income Tax Expense (Benefit)	7,045	12,183
Interest and Debt Expense	23,768	25,083
Net Income (Loss) Attributable to Parent	32,303	26,996
Assets	4,742,091	4,740,561	$ 4,740,561
Cash	4,600		18,300
Other Long-term Investments	$ 4,000		$ 5,100
Nonutility assets representation rate, percentage	1.00%
Electric [Member]
Segment Reporting Information [Line Items]
Electric Revenue	$ 354,504	336,909
Income Tax Expense (Benefit)	9,056	15,724
Interest and Debt Expense	16,068	16,073
Net Income (Loss) Attributable to Parent	38,108	32,270
Assets	4,733,584	4,719,547
Other Segments [Member]
Segment Reporting Information [Line Items]
Income Tax Expense (Benefit)	(2,011)	(3,541)
Interest and Debt Expense	7,700	9,010
Net Income (Loss) Attributable to Parent	(5,805)	(5,274)
Assets	$ 8,507	$ 21,014

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 31, 2018
Disaggregation of Revenue [Line Items]
Contract with Customer, Asset, Gross	$ 152,900		$ 155,700
Revenue from Contract with Customer, Excluding Assessed Tax	352,300
UTILITY OPERATING REVENUES	354,504	$ 336,909
Retail Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	348,500
Other non-606 revenue	919
Wholesale Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,510
Miscellaneous revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,243
Other non-606 revenue	$ 1,332