Document And Entity Information
Document And Entity Information | 9 Months Ended |
Sep. 30, 2017shares | |
Entity Registrant Name | ALLIANT ENERGY CORP |
Entity Central Index Key | 352,541 |
Current Fiscal Year End Date | --12-31 |
Entity Filer Category | Large Accelerated Filer |
Entity Common Stock, Shares Outstanding | 231,204,360 |
Document Fiscal Year Focus | 2,017 |
Document Fiscal Period Focus | Q3 |
Document Type | 10-Q |
Amendment Flag | false |
Document Period End Date | Sep. 30, 2017 |
IPL [Member] | |
Entity Registrant Name | INTERSTATE POWER & LIGHT CO |
Entity Central Index Key | 52,485 |
Entity Filer Category | Non-accelerated Filer |
Entity Common Stock, Shares Outstanding | 13,370,788 |
WPL [Member] | |
Entity Registrant Name | WISCONSIN POWER & LIGHT CO |
Entity Central Index Key | 107,832 |
Entity Filer Category | Non-accelerated Filer |
Entity Common Stock, Shares Outstanding | 13,236,601 |
Condensed Consolidated Statemen
Condensed Consolidated Statements Of Income - USD ($) shares in Millions, $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Operating revenues: | ||||
Electric utility | $ 840.6 | $ 864.3 | $ 2,199.1 | $ 2,209.1 |
Gas utility | 45.8 | 39.5 | 262.7 | 248.7 |
Other utility | 11.2 | 9.4 | 34.4 | 35 |
Non-regulated | 9.3 | 11.4 | 29.9 | 30.2 |
Total operating revenues | 906.9 | 924.6 | 2,526.1 | 2,523 |
Operating expenses: | ||||
Electric production fuel and purchased power | 222.6 | 245.9 | 614.7 | 646.3 |
Electric transmission service | 121 | 138.6 | 363.3 | 396.8 |
Cost of gas sold | 15 | 12.5 | 135.5 | 132.3 |
Asset valuation charges for Franklin County wind farm | 0 | 86.4 | 0 | 86.4 |
Other operation and maintenance | 169.1 | 148.6 | 467.1 | 438.2 |
Depreciation and amortization | 120.7 | 104.1 | 342.7 | 308.7 |
Taxes other than income taxes | 27 | 25.9 | 79.1 | 77.2 |
Total operating expenses | 675.4 | 762 | 2,002.4 | 2,085.9 |
Operating income | 231.5 | 162.6 | 523.7 | 437.1 |
Interest expense and other: | ||||
Interest expense | 53.9 | 48.8 | 159 | 144.8 |
Equity income from unconsolidated investments, net | (10.1) | (9.2) | (32.9) | (28.8) |
Allowance for funds used during construction | (9.6) | (15.8) | (36.7) | (44.3) |
Interest income and other | (0.2) | (0.1) | (0.4) | (0.3) |
Total interest expense and other | 34 | 23.7 | 89 | 71.4 |
Income from continuing operations before income taxes | 197.5 | 138.9 | 434.7 | 365.7 |
Income tax expense (benefit) | 26.1 | 7.5 | 64.9 | 47.2 |
Income from continuing operations, net of tax | 171.4 | 131.4 | 369.8 | 318.5 |
Income (loss) from discontinued operations, net of tax | 0 | (0.4) | 1.4 | (2) |
Net income | 171.4 | 131 | 371.2 | 316.5 |
Preferred dividend requirements of Interstate Power and Light Company | 2.6 | 2.6 | 7.7 | 7.7 |
Net income attributable to common shareowners | $ 168.8 | $ 128.4 | $ 363.5 | $ 308.8 |
Weighted average number of common shares outstanding (basic and diluted) (in shares) | 231 | 227.2 | 229.2 | 227 |
Earnings per weighted average common share attributable to Alliant Energy common shareowners (basic and diluted): | ||||
Income from continuing operations, net of tax (basic and diluted) (in dollars per share) | $ 0.73 | $ 0.57 | $ 1.58 | $ 1.37 |
Income (loss) from discontinued operations, net of tax (basic and diluted) (in dollars per share) | 0 | 0 | 0.01 | (0.01) |
Earnings per weighted average common share attributable to Alliant Energy common shareowners (basic and diluted) (in dollars per share) | $ 0.73 | $ 0.57 | $ 1.59 | $ 1.36 |
Amounts attributable to common shareowners: | ||||
Income from continuing operations, net of tax | $ 168.8 | $ 128.8 | $ 362.1 | $ 310.8 |
Income (loss) from discontinued operations, net of tax | 0 | (0.4) | 1.4 | (2) |
Net income attributable to common shareowners | $ 168.8 | $ 128.4 | $ 363.5 | $ 308.8 |
Dividends declared per common share (in dollars per share) | $ 0.315 | $ 0.29375 | $ 0.945 | $ 0.88125 |
IPL [Member] | ||||
Operating revenues: | ||||
Electric utility | $ 489 | $ 483.2 | $ 1,217.6 | $ 1,209.2 |
Gas utility | 27.4 | 23.9 | 147.2 | 142.6 |
Other utility | 11 | 9.1 | 33.3 | 34.1 |
Total operating revenues | 527.4 | 516.2 | 1,398.1 | 1,385.9 |
Operating expenses: | ||||
Electric production fuel and purchased power | 122.5 | 125 | 330 | 324.8 |
Electric transmission service | 78.2 | 95.9 | 235 | 270.7 |
Cost of gas sold | 9.9 | 8 | 74.6 | 76.3 |
Other operation and maintenance | 104.4 | 94.8 | 288.7 | 279.8 |
Depreciation and amortization | 66.2 | 52.7 | 181 | 157.8 |
Taxes other than income taxes | 14.4 | 13.9 | 41.1 | 40.6 |
Total operating expenses | 395.6 | 390.3 | 1,150.4 | 1,150 |
Operating income | 131.8 | 125.9 | 247.7 | 235.9 |
Interest expense and other: | ||||
Interest expense | 27.9 | 25.5 | 83.5 | 75.4 |
Allowance for funds used during construction | (4.7) | (13.8) | (25.1) | (36.2) |
Interest income and other | (0.1) | 0 | (0.2) | (0.1) |
Total interest expense and other | 23.1 | 11.7 | 58.2 | 39.1 |
Income from continuing operations before income taxes | 108.7 | 114.2 | 189.5 | 196.8 |
Income tax expense (benefit) | (14.3) | (2.5) | (18.6) | (2.5) |
Net income | 123 | 116.7 | 208.1 | 199.3 |
Preferred dividend requirements of Interstate Power and Light Company | 2.6 | 2.6 | 7.7 | 7.7 |
Net income attributable to common shareowners | 120.4 | 114.1 | 200.4 | 191.6 |
Amounts attributable to common shareowners: | ||||
Net income attributable to common shareowners | 120.4 | 114.1 | 200.4 | 191.6 |
WPL [Member] | ||||
Operating revenues: | ||||
Electric utility | 351.6 | 381.1 | 981.5 | 999.9 |
Gas utility | 18.4 | 15.6 | 115.5 | 106.1 |
Other utility | 0.2 | 0.3 | 1.1 | 0.9 |
Total operating revenues | 370.2 | 397 | 1,098.1 | 1,106.9 |
Operating expenses: | ||||
Electric production fuel and purchased power | 100.1 | 120.9 | 284.7 | 321.5 |
Electric transmission service | 42.8 | 42.7 | 128.3 | 126.1 |
Cost of gas sold | 5.1 | 4.5 | 60.9 | 56 |
Other operation and maintenance | 66.1 | 54.2 | 179.7 | 157.2 |
Depreciation and amortization | 53.6 | 48.7 | 158.8 | 143.5 |
Taxes other than income taxes | 11.8 | 11 | 35.3 | 33.8 |
Total operating expenses | 279.5 | 282 | 847.7 | 838.1 |
Operating income | 90.7 | 115 | 250.4 | 268.8 |
Interest expense and other: | ||||
Interest expense | 23.1 | 22.9 | 69.1 | 68.7 |
Equity income from unconsolidated investments, net | (0.2) | (9.3) | (0.4) | (29) |
Allowance for funds used during construction | (4.9) | (2) | (11.6) | (8.1) |
Interest income and other | (0.1) | 0.1 | (0.2) | (0.2) |
Total interest expense and other | 17.9 | 11.7 | 56.9 | 31.4 |
Income from continuing operations before income taxes | 72.8 | 103.3 | 193.5 | 237.4 |
Income tax expense (benefit) | 23 | 33.7 | 60.1 | 77.1 |
Net income | 49.8 | 69.6 | 133.4 | 160.3 |
Net income attributable to noncontrolling interest | 0 | 0.6 | 0 | 1.6 |
Net income attributable to common shareowners | 49.8 | 69 | 133.4 | 158.7 |
Amounts attributable to common shareowners: | ||||
Net income attributable to common shareowners | $ 49.8 | $ 69 | $ 133.4 | $ 158.7 |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 |
Current assets: | ||
Cash and cash equivalents | $ 9.2 | $ 8.2 |
Accounts receivable, less allowance for doubtful accounts | 336.1 | 493.3 |
Production fuel, at weighted average cost | 80.9 | 98.1 |
Gas stored underground, at weighted average cost | 40.6 | 37.6 |
Materials and supplies, at weighted average cost | 99.1 | 86.6 |
Regulatory assets | 84.2 | 57.8 |
Other | 101.4 | 95.5 |
Total current assets | 751.5 | 877.1 |
Property, plant and equipment, net | 10,931.1 | 10,279.2 |
Investments: | ||
ATC Investment | 339.2 | 317.6 |
Other | 119.4 | 20 |
Total investments | 458.6 | 337.6 |
Other assets: | ||
Regulatory assets | 1,952.3 | 1,857.3 |
Deferred charges and other | 21.4 | 22.6 |
Total other assets | 1,973.7 | 1,879.9 |
Total assets | 14,114.9 | 13,373.8 |
Current liabilities: | ||
Current maturities of long-term debt | 105.2 | 4.6 |
Commercial paper | 390.3 | 244.1 |
Other short-term borrowings | 95 | 0 |
Accounts payable | 478.1 | 445.3 |
Regulatory liabilities | 145.1 | 186.2 |
Accrued taxes | 39.4 | 59.5 |
Other | 217 | 222.3 |
Total current liabilities | 1,470.1 | 1,162 |
Long-term debt, net (excluding current portion) | 4,255.1 | 4,315.6 |
Other liabilities: | ||
Deferred tax liabilities | 2,774.7 | 2,570.2 |
Regulatory liabilities | 483.4 | 494.8 |
Pension and other benefit obligations | 481.3 | 489.9 |
Other | 296.1 | 279.3 |
Total other liabilities | 4,035.5 | 3,834.2 |
Commitments and contingencies (Note 12) | ||
Common equity: | ||
Common stock | 2.3 | 2.3 |
Additional paid-in capital | 1,838.2 | 1,693.1 |
Retained earnings | 2,324.8 | 2,177 |
Accumulated other comprehensive loss | (0.4) | (0.4) |
Shares in deferred compensation trust - 454,532 and 441,695 shares at a weighted average cost of $23.52 and $22.71 per share | (10.7) | (10) |
Total common equity | 4,154.2 | 3,862 |
Cumulative preferred stock of Interstate Power and Light Company | 200 | 200 |
Total equity | 4,354.2 | 4,062 |
Total liabilities and equity | 14,114.9 | 13,373.8 |
IPL [Member] | ||
Current assets: | ||
Cash and cash equivalents | 4.7 | 3.3 |
Accounts receivable, less allowance for doubtful accounts | 143.5 | 240.7 |
Production fuel, at weighted average cost | 56.7 | 70.3 |
Gas stored underground, at weighted average cost | 21.6 | 16.3 |
Materials and supplies, at weighted average cost | 52.6 | 46.5 |
Regulatory assets | 38.9 | 17.7 |
Other | 39.3 | 27.7 |
Total current assets | 357.3 | 422.5 |
Property, plant and equipment, net | 5,764.9 | 5,435.6 |
Other assets: | ||
Regulatory assets | 1,552 | 1,441.1 |
Deferred charges and other | 8.5 | 5.5 |
Total other assets | 1,560.5 | 1,446.6 |
Total assets | 7,682.7 | 7,304.7 |
Current liabilities: | ||
Current maturities of long-term debt | 100 | 0 |
Commercial paper | 4 | 0 |
Accounts payable | 224.6 | 186.3 |
Accounts payable to associated companies | 56.4 | 43.3 |
Regulatory liabilities | 85.9 | 149.6 |
Accrued taxes | 39.3 | 53.8 |
Other | 92.8 | 88.8 |
Total current liabilities | 603 | 521.8 |
Long-term debt, net (excluding current portion) | 2,095 | 2,153.5 |
Other liabilities: | ||
Deferred tax liabilities | 1,643.5 | 1,511.8 |
Regulatory liabilities | 298.9 | 281.2 |
Pension and other benefit obligations | 171.4 | 173.2 |
Other | 238.5 | 214.2 |
Total other liabilities | 2,352.3 | 2,180.4 |
Commitments and contingencies (Note 12) | ||
Common equity: | ||
Common stock | 33.4 | 33.4 |
Additional paid-in capital | 1,697.8 | 1,597.8 |
Retained earnings | 701.2 | 617.8 |
Total common equity | 2,432.4 | 2,249 |
Cumulative preferred stock of Interstate Power and Light Company | 200 | 200 |
Total equity | 2,632.4 | 2,449 |
Total liabilities and equity | 7,682.7 | 7,304.7 |
WPL [Member] | ||
Current assets: | ||
Cash and cash equivalents | 3.2 | 4.2 |
Accounts receivable, less allowance for doubtful accounts | 185.8 | 226.3 |
Production fuel, at weighted average cost | 24.2 | 27.8 |
Gas stored underground, at weighted average cost | 19 | 21.3 |
Materials and supplies, at weighted average cost | 43.6 | 36.3 |
Regulatory assets | 45.3 | 40.1 |
Other | 64.6 | 60.5 |
Total current assets | 385.7 | 416.5 |
Property, plant and equipment, net | 4,782.4 | 4,426.7 |
Other assets: | ||
Regulatory assets | 400.3 | 416.2 |
Deferred charges and other | 25.7 | 30.9 |
Total other assets | 426 | 447.1 |
Total assets | 5,594.1 | 5,290.3 |
Current liabilities: | ||
Commercial paper | 224.6 | 52.3 |
Accounts payable | 197.2 | 192.9 |
Regulatory liabilities | 59.2 | 36.6 |
Other | 108.7 | 112.9 |
Total current liabilities | 589.7 | 394.7 |
Long-term debt, net (excluding current portion) | 1,536.2 | 1,535.2 |
Other liabilities: | ||
Deferred tax liabilities | 1,035.2 | 971.6 |
Regulatory liabilities | 184.5 | 213.6 |
Capital lease obligations - Sheboygan Falls Energy Facility | 72 | 77.2 |
Pension and other benefit obligations | 204.2 | 207.8 |
Other | 162.6 | 159.4 |
Total other liabilities | 1,658.5 | 1,629.6 |
Commitments and contingencies (Note 12) | ||
Common equity: | ||
Common stock | 66.2 | 66.2 |
Additional paid-in capital | 1,059 | 1,019 |
Retained earnings | 684.5 | 645.6 |
Total common equity | 1,809.7 | 1,730.8 |
Total liabilities and equity | $ 5,594.1 | $ 5,290.3 |
Condensed Consolidated Balance4
Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2017 | Dec. 31, 2016 |
Common stock, par value | $ 0.01 | $ 0.01 |
Common stock, shares authorized (in shares) | 480,000,000 | 480,000,000 |
Common stock, shares outstanding (in shares) | 231,204,360 | 227,673,654 |
Shares in deferred compensation trust (in shares) | 454,532 | 441,695 |
Shares in deferred compensation trust, weighted average cost per share (in dollars per share) | $ 23.52 | $ 22.71 |
IPL [Member] | ||
Common stock, par value | $ 2.50 | $ 2.50 |
Common stock, shares authorized (in shares) | 24,000,000 | 24,000,000 |
Common stock, shares outstanding (in shares) | 13,370,788 | 13,370,788 |
WPL [Member] | ||
Common stock, par value | $ 5 | $ 5 |
Common stock, shares authorized (in shares) | 18,000,000 | 18,000,000 |
Common stock, shares outstanding (in shares) | 13,236,601 | 13,236,601 |
Condensed Consolidated Stateme5
Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions | 9 Months Ended | |
Sep. 30, 2017 | Sep. 30, 2016 | |
Cash flows from operating activities: | ||
Net income | $ 371.2 | $ 316.5 |
Adjustments to reconcile net income to net cash flows from operating activities: | ||
Depreciation and amortization | 342.7 | 308.7 |
Deferred tax expense and tax credits | 102.7 | 76.7 |
Asset valuation charges for Franklin County wind farm | 0 | 86.4 |
Other | (7.1) | (44) |
Other changes in assets and liabilities: | ||
Accounts receivable | 72.8 | (101) |
Sales of accounts receivable | 91 | (4) |
Regulatory assets | (108.9) | 36.6 |
Regulatory liabilities | (64.8) | (66.5) |
Deferred income taxes | 101 | 71.8 |
Other | (17.2) | (27.2) |
Net cash flows from operating activities | 883.4 | 654 |
Cash flows used for investing activities: | ||
Utility business construction and acquisition expenditures | (909.7) | (743.6) |
Alliant Energy Corporate Services, Inc. and non-regulated businesses construction and acquisition expenditures | (139.7) | (43.3) |
Other | (22.9) | 15.1 |
Net cash flows used for investing activities | (1,072.3) | (771.8) |
Cash flows from (used for) financing activities: | ||
Common stock dividends | (215.7) | (199.8) |
Proceeds from issuance of common stock, net | 143.2 | 20.4 |
Proceeds from issuance of long-term debt | 0 | 300 |
Net change in commercial paper and other short-term borrowings | 281.2 | 78.5 |
Other | (18.8) | (2.4) |
Net cash flows from (used for) financing activities | 189.9 | 196.7 |
Net increase (decrease) in cash and cash equivalents | 1 | 78.9 |
Cash and cash equivalents at beginning of period | 8.2 | 5.8 |
Cash and cash equivalents at end of period | 9.2 | 84.7 |
Supplemental cash flows information: | ||
Interest, net of capitalized interest | (158.5) | (140.7) |
Income taxes, net | (11.4) | (8.3) |
Significant non-cash investing and financing activities: | ||
Accrued capital expenditures | 197.2 | 99.9 |
IPL [Member] | ||
Cash flows from operating activities: | ||
Net income | 208.1 | 199.3 |
Adjustments to reconcile net income to net cash flows from operating activities: | ||
Depreciation and amortization | 181 | 157.8 |
Other | 26.2 | 24.3 |
Other changes in assets and liabilities: | ||
Accounts receivable | 12.4 | (66.5) |
Sales of accounts receivable | 91 | (4) |
Regulatory assets | (107.8) | (14.1) |
Regulatory liabilities | (49.6) | (64.5) |
Deferred income taxes | 88.9 | 67.7 |
Other | 20.4 | (43.5) |
Net cash flows from operating activities | 470.6 | 256.5 |
Cash flows used for investing activities: | ||
Utility business construction and acquisition expenditures | (470.1) | (436.5) |
Other | (23.5) | 1.1 |
Net cash flows used for investing activities | (493.6) | (435.4) |
Cash flows from (used for) financing activities: | ||
Common stock dividends | (117) | (114) |
Capital contributions from parent | 100 | 65 |
Proceeds from issuance of long-term debt | 0 | 300 |
Net change in commercial paper and other short-term borrowings | 44 | 0 |
Other | (2.6) | 1.1 |
Net cash flows from (used for) financing activities | 24.4 | 252.1 |
Net increase (decrease) in cash and cash equivalents | 1.4 | 73.2 |
Cash and cash equivalents at beginning of period | 3.3 | 4.5 |
Cash and cash equivalents at end of period | 4.7 | 77.7 |
Supplemental cash flows information: | ||
Interest, net of capitalized interest | (84.1) | (72.5) |
Income taxes, net | 13.2 | 0.7 |
Significant non-cash investing and financing activities: | ||
Accrued capital expenditures | 71 | 44.5 |
WPL [Member] | ||
Cash flows from operating activities: | ||
Net income | 133.4 | 160.3 |
Adjustments to reconcile net income to net cash flows from operating activities: | ||
Depreciation and amortization | 158.8 | 143.5 |
Deferred tax expense and tax credits | 60.1 | 97.9 |
Other | 4.8 | (20.3) |
Other changes in assets and liabilities: | ||
Accounts receivable | 41.8 | (12.8) |
Regulatory assets | (1.1) | 50.7 |
Other | (36.6) | 20 |
Net cash flows from operating activities | 361.2 | 439.3 |
Cash flows used for investing activities: | ||
Utility business construction and acquisition expenditures | (454) | (307.1) |
Other | (16.2) | (19.6) |
Net cash flows used for investing activities | (470.2) | (326.7) |
Cash flows from (used for) financing activities: | ||
Common stock dividends | (94.5) | (101.2) |
Capital contributions from parent | 40 | 0 |
Net change in commercial paper and other short-term borrowings | 172.3 | (8.1) |
Other | (9.8) | 1.9 |
Net cash flows from (used for) financing activities | 108 | (107.4) |
Net increase (decrease) in cash and cash equivalents | (1) | 5.2 |
Cash and cash equivalents at beginning of period | 4.2 | 0.4 |
Cash and cash equivalents at end of period | 3.2 | 5.6 |
Supplemental cash flows information: | ||
Interest, net of capitalized interest | (68.1) | (67.7) |
Income taxes, net | (20.2) | 19.6 |
Significant non-cash investing and financing activities: | ||
Accrued capital expenditures | $ 122.3 | $ 50.8 |
Summary Of Significant Accounti
Summary Of Significant Accounting Policies | 9 Months Ended |
Sep. 30, 2017 | |
Summary Of Significant Accounting Policies | SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES NOTE 1(a) General - The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the latest combined Annual Report on Form 10-K. In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2017 are not necessarily indicative of results that may be expected for the year ending December 31, 2017 . A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes. Discontinued operations reported in Alliant Energy’s income statements is related to various warranty claims associated with the sale of RMT in 2013, which have resulted in operating expenses and income subsequent to the sale. NOTE 1(b) New Accounting Standards - Revenue Recognition - In May 2014, the Financial Accounting Standards Board issued an accounting standard providing principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This standard also requires disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018 and currently expect to use the modified retrospective method of adoption. If applicable, this method requires a cumulative-effect adjustment to the opening retained earnings balance on January 1, 2018, as if the standard had always been in effect. Alliant Energy, IPL and WPL have continued to make progress in the evaluation of the revenue recognition standard and do not currently anticipate a significant change in revenue recognition for retail electric and gas sales. These sales represent the majority of Alliant Energy’s, IPL’s and WPL’s revenues and are from tariff offerings that provide electricity or natural gas without a defined contractual term. For such arrangements, revenues from contracts with customers will be equivalent to the electricity or natural gas supplied and billed, or estimated to be billed, and there will be no significant shift in the timing or pattern of revenue recognition for such sales. The most significant impact to the financial statements for Alliant Energy, IPL and WPL is expected to be in the form of additional disclosures. The incremental disclosures could include disaggregation of revenue by location and customer class. Alliant Energy, IPL and WPL expect to complete the evaluation of the impact of the revenue recognition standard on their financial condition, results of operations and disclosures by January 1, 2018. Leases - In February 2016, the Financial Accounting Standards Board issued an accounting standard requiring lease assets and lease liabilities, including operating leases, to be recognized on the balance sheet for all leases with terms longer than 12 months. The standard also requires disclosure of key information about leasing arrangements. Alliant Energy, IPL and WPL currently expect to adopt this standard on January 1, 2019 and are evaluating the impact of this standard on their financial condition and results of operations and expect an increase in assets and liabilities from recognizing operating leases on their balance sheets. Presentation of Net Periodic Pension and Postretirement Benefit Costs - In March 2017, the Financial Accounting Standards Board issued an accounting standard amending the income statement presentation of the components of net periodic benefit costs for defined benefit pension and other postretirement plans. The standard requires entities to (1) disaggregate the current service cost component from the other components of net periodic benefit costs and present it with other employee compensation costs in the income statement; and (2) include the other components in the income statement outside of operating income. This new presentation will shift the majority of the net periodic benefit costs from “Other operation and maintenance” expenses to “Interest expense and other” expenses in the income statements. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization into property, plant and equipment, when applicable. IPL and WPL, as rate-regulated entities, currently expect to capitalize the other components of net periodic benefit costs into regulatory assets or regulatory liabilities. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018. Upon adoption, the standard must be applied retrospectively for the presentation requirements and prospectively for the capitalization requirements. Alliant Energy, IPL and WPL continue to evaluate additional impacts of this standard on their financial condition and results of operations. |
IPL [Member] | |
Summary Of Significant Accounting Policies | SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES NOTE 1(a) General - The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the latest combined Annual Report on Form 10-K. In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2017 are not necessarily indicative of results that may be expected for the year ending December 31, 2017 . A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes. Discontinued operations reported in Alliant Energy’s income statements is related to various warranty claims associated with the sale of RMT in 2013, which have resulted in operating expenses and income subsequent to the sale. NOTE 1(b) New Accounting Standards - Revenue Recognition - In May 2014, the Financial Accounting Standards Board issued an accounting standard providing principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This standard also requires disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018 and currently expect to use the modified retrospective method of adoption. If applicable, this method requires a cumulative-effect adjustment to the opening retained earnings balance on January 1, 2018, as if the standard had always been in effect. Alliant Energy, IPL and WPL have continued to make progress in the evaluation of the revenue recognition standard and do not currently anticipate a significant change in revenue recognition for retail electric and gas sales. These sales represent the majority of Alliant Energy’s, IPL’s and WPL’s revenues and are from tariff offerings that provide electricity or natural gas without a defined contractual term. For such arrangements, revenues from contracts with customers will be equivalent to the electricity or natural gas supplied and billed, or estimated to be billed, and there will be no significant shift in the timing or pattern of revenue recognition for such sales. The most significant impact to the financial statements for Alliant Energy, IPL and WPL is expected to be in the form of additional disclosures. The incremental disclosures could include disaggregation of revenue by location and customer class. Alliant Energy, IPL and WPL expect to complete the evaluation of the impact of the revenue recognition standard on their financial condition, results of operations and disclosures by January 1, 2018. Leases - In February 2016, the Financial Accounting Standards Board issued an accounting standard requiring lease assets and lease liabilities, including operating leases, to be recognized on the balance sheet for all leases with terms longer than 12 months. The standard also requires disclosure of key information about leasing arrangements. Alliant Energy, IPL and WPL currently expect to adopt this standard on January 1, 2019 and are evaluating the impact of this standard on their financial condition and results of operations and expect an increase in assets and liabilities from recognizing operating leases on their balance sheets. Presentation of Net Periodic Pension and Postretirement Benefit Costs - In March 2017, the Financial Accounting Standards Board issued an accounting standard amending the income statement presentation of the components of net periodic benefit costs for defined benefit pension and other postretirement plans. The standard requires entities to (1) disaggregate the current service cost component from the other components of net periodic benefit costs and present it with other employee compensation costs in the income statement; and (2) include the other components in the income statement outside of operating income. This new presentation will shift the majority of the net periodic benefit costs from “Other operation and maintenance” expenses to “Interest expense and other” expenses in the income statements. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization into property, plant and equipment, when applicable. IPL and WPL, as rate-regulated entities, currently expect to capitalize the other components of net periodic benefit costs into regulatory assets or regulatory liabilities. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018. Upon adoption, the standard must be applied retrospectively for the presentation requirements and prospectively for the capitalization requirements. Alliant Energy, IPL and WPL continue to evaluate additional impacts of this standard on their financial condition and results of operations. |
WPL [Member] | |
Summary Of Significant Accounting Policies | SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES NOTE 1(a) General - The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the latest combined Annual Report on Form 10-K. In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2017 are not necessarily indicative of results that may be expected for the year ending December 31, 2017 . A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes. Discontinued operations reported in Alliant Energy’s income statements is related to various warranty claims associated with the sale of RMT in 2013, which have resulted in operating expenses and income subsequent to the sale. NOTE 1(b) New Accounting Standards - Revenue Recognition - In May 2014, the Financial Accounting Standards Board issued an accounting standard providing principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This standard also requires disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018 and currently expect to use the modified retrospective method of adoption. If applicable, this method requires a cumulative-effect adjustment to the opening retained earnings balance on January 1, 2018, as if the standard had always been in effect. Alliant Energy, IPL and WPL have continued to make progress in the evaluation of the revenue recognition standard and do not currently anticipate a significant change in revenue recognition for retail electric and gas sales. These sales represent the majority of Alliant Energy’s, IPL’s and WPL’s revenues and are from tariff offerings that provide electricity or natural gas without a defined contractual term. For such arrangements, revenues from contracts with customers will be equivalent to the electricity or natural gas supplied and billed, or estimated to be billed, and there will be no significant shift in the timing or pattern of revenue recognition for such sales. The most significant impact to the financial statements for Alliant Energy, IPL and WPL is expected to be in the form of additional disclosures. The incremental disclosures could include disaggregation of revenue by location and customer class. Alliant Energy, IPL and WPL expect to complete the evaluation of the impact of the revenue recognition standard on their financial condition, results of operations and disclosures by January 1, 2018. Leases - In February 2016, the Financial Accounting Standards Board issued an accounting standard requiring lease assets and lease liabilities, including operating leases, to be recognized on the balance sheet for all leases with terms longer than 12 months. The standard also requires disclosure of key information about leasing arrangements. Alliant Energy, IPL and WPL currently expect to adopt this standard on January 1, 2019 and are evaluating the impact of this standard on their financial condition and results of operations and expect an increase in assets and liabilities from recognizing operating leases on their balance sheets. Presentation of Net Periodic Pension and Postretirement Benefit Costs - In March 2017, the Financial Accounting Standards Board issued an accounting standard amending the income statement presentation of the components of net periodic benefit costs for defined benefit pension and other postretirement plans. The standard requires entities to (1) disaggregate the current service cost component from the other components of net periodic benefit costs and present it with other employee compensation costs in the income statement; and (2) include the other components in the income statement outside of operating income. This new presentation will shift the majority of the net periodic benefit costs from “Other operation and maintenance” expenses to “Interest expense and other” expenses in the income statements. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization into property, plant and equipment, when applicable. IPL and WPL, as rate-regulated entities, currently expect to capitalize the other components of net periodic benefit costs into regulatory assets or regulatory liabilities. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018. Upon adoption, the standard must be applied retrospectively for the presentation requirements and prospectively for the capitalization requirements. Alliant Energy, IPL and WPL continue to evaluate additional impacts of this standard on their financial condition and results of operations. |
Regulatory Matters
Regulatory Matters | 9 Months Ended |
Sep. 30, 2017 | |
Public Utilities, General Disclosures [Line Items] | |
Regulatory Matters | REGULATORY MATTERS Regulatory Assets and Regulatory Liabilities - Regulatory assets were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Tax-related $1,147.9 $1,055.6 $1,107.9 $1,022.4 $40.0 $33.2 Pension and OPEB costs 547.8 578.7 279.3 294.0 268.5 284.7 Asset retirement obligations 107.9 105.9 71.9 64.3 36.0 41.6 EGUs retired early 67.4 41.4 32.9 — 34.5 41.4 Derivatives 49.9 30.7 22.3 10.0 27.6 20.7 Emission allowances 25.6 26.2 25.6 26.2 — — Other 90.0 76.6 51.0 41.9 39.0 34.7 $2,036.5 $1,915.1 $1,590.9 $1,458.8 $445.6 $456.3 Regulatory liabilities were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Cost of removal obligations $412.1 $411.6 $272.9 $269.4 $139.2 $142.2 Electric transmission cost recovery 94.8 72.0 35.9 35.7 58.9 36.3 IPL’s tax benefit riders 45.0 83.5 45.0 83.5 — — Commodity cost recovery 21.2 30.8 15.0 17.8 6.2 13.0 Energy efficiency cost recovery 20.0 20.5 — — 20.0 20.5 Derivatives 10.9 31.5 5.8 12.1 5.1 19.4 Other 24.5 31.1 10.2 12.3 14.3 18.8 $628.5 $681.0 $384.8 $430.8 $243.7 $250.2 Tax-related - Alliant Energy’s and IPL’s tax-related regulatory assets are generally impacted by certain property-related differences at IPL for which deferred tax is not recorded in the income statement pursuant to Iowa rate-making principles. Deferred tax amounts for such property-related differences at IPL are recorded to regulatory assets, along with the necessary revenue requirement tax gross-ups. During the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s tax-related regulatory assets increased primarily due to property-related differences for qualifying repair expenditures. Asset retirement obligations - In September 2017, IPL reached a partial settlement agreement related to its retail electric rate review (2016 Test Year), subject to IUB approval. The proposed settlement does not include the recovery of certain asset retirement obligation costs previously recorded as regulatory assets, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below. Electric generating units retired early - In June 2017, IPL retired Sutherland Units 1 and 3 and reclassified the remaining net book value of these EGUs from property, plant and equipment to a regulatory asset on Alliant Energy’s and IPL’s balance sheets. IPL is currently earning a return on the remaining net book value of these EGUs, as well as recovering the remaining net book value of these EGUs from both its retail and wholesale customers. IPL’s proposed settlement reached in September 2017 includes recovery of the remaining net book value of these EGUs from IPL’s retail customers over a 10 -year period. However, the proposed settlement does not allow IPL to earn a return on the remaining net book value of these EGUs from its retail customers when final rates are implemented, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below. IPL has requested continued recovery of the remaining net book value of these EGUs from its retail customers over a 10 -year period from the IUB, with a decision currently expected in the first quarter of 2018. In September 2017, FERC approved continued recovery of the remaining net book value of these EGUs from IPL’s wholesale customers over a 10 -year period. Derivatives - Refer to Note 11 for discussion of derivative assets and derivative liabilities. Electric transmission cost recovery - A group of MISO cooperative and municipal utilities previously filed two complaints with FERC requesting a reduction to the base return on equity used by MISO transmission owners, including ITC and ATC LLC, to determine electric transmission costs billed to utilities, including IPL and WPL. In September 2016, FERC issued an order on the first complaint and established a base return on equity of 10.32% , excluding any incentive adders granted by FERC, effective September 28, 2016, and for the refund period from November 12, 2013 through February 11, 2015 (first complaint period). During the nine months ended September 30, 2017, Alliant Energy, IPL and WPL received the refunds for the first complaint period of $50 million , $39 million and $11 million , respectively, after final true-ups. IPL and WPL each initially recorded the retail portion of the refunds to a regulatory liability. Pursuant to IUB approval, IPL’s retail portion of the refund from ITC is currently being refunded to its retail customers in 2017. WPL’s retail portion of the refund from ATC LLC will remain in a regulatory liability until such refunds are approved to be returned to retail customers in a future rate proceeding. IPL’s and WPL’s wholesale customers received their share of the refunds through normal monthly billing practices in 2017. IPL’s tax benefit riders - IPL’s tax benefit riders utilize regulatory liabilities to credit bills of IPL’s Iowa retail electric and gas customers to help offset the impact of rate increases on such customers. These regulatory liabilities are related to tax benefits from tax accounting method changes for repairs expenditures and cost of removal expenditures, and a rate-making accounting change for capitalized interest. For the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s “IPL’s tax benefit riders” regulatory liabilities decreased by ($39) million as follows (in millions): Electric tax benefit rider credits ($51 ) Gas tax benefit rider credits (5 ) Rate-making accounting change 17 ($39 ) In the third quarter of 2017, Alliant Energy and IPL implemented a rate-making accounting change for capitalized interest. IPL currently anticipates crediting its related tax benefits from this rate-making accounting change to its Iowa retail electric and gas customers in the future, and as a result, Alliant Energy and IPL recorded an increase of $17 million to IPL’s tax benefit riders regulatory liabilities during the nine months ended September 30, 2017. Utility Rate Reviews - IPL’s Retail Electric Rate Review (2016 Test Year) - In April 2017, IPL filed a request with the IUB to increase annual electric base rates for its Iowa retail electric customers by $176 million , or approximately 12% . The request was based on a 2016 historical Test Year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of capital projects, primarily power grid modernization and investments that advance cleaner energy, including Marshalltown. An interim retail electric base rate increase of $102 million , or approximately 7% , on an annual basis, was implemented effective April 13, 2017, without regulatory review, and will be subject to refund pending determination of final rates. Tax benefit rider credits and MISO transmission owner return on equity refunds are expected to reduce the effect of the rate increase on customer bills in 2017 and 2018. For the three and nine months ended September 30, 2017 , Alliant Energy and IPL recorded increases in electric base rates of $34 million and $54 million , respectively, in conjunction with the interim retail electric base rate increase. In September 2017, IPL reached a partial, non-unanimous settlement agreement with the Iowa Office of Consumer Advocate, the Iowa Business Energy Coalition and the Large Energy Group for an annual electric base rate increase of $130 million , or approximately 9% . The final proposed rate increase (based on proposed settlement) includes increased depreciation expense resulting from an updated depreciation study; recovery over a four -year period of asset retirement obligation expenditures since the last retail electric rate filing in 2010; recovery over a 10 -year period of the remaining net book value of Sutherland Units 1 and 3, unamortized forward contract costs for SO2 emission allowances through the energy adjustment clause and cancelled project costs approved in a prior emissions plan and budget; and no double leverage applied to the weighted-average cost of capital. The proposed settlement did not address rate design or IPL’s proposal to continue the electric transmission cost rider. As a result of the proposed settlement, in the third quarter of 2017, IPL recorded a write-down of regulatory assets of $9 million , including $4 million to “Other operation and maintenance” expenses primarily related to IPL being no longer probable of earning a return on the remaining net book value of Sutherland Units 1 and 3 from its retail customers when final rates are implemented, and $5 million to “Depreciation and amortization” expenses for asset retirement obligations deemed no longer probable of recovery in future rates. IPL currently expects to implement final rates in the first quarter of 2018. The IUB must issue a decision on requests for retail rate changes within 10 months of the date of the application for which changes are filed. WPL’s Retail Electric and Gas Rate Review (2017/2018 Test Period) - In December 2016, WPL received an order from the PSCW authorizing WPL to implement an increase in annual retail electric rates of $9 million , or approximately 1% , and an increase in annual retail gas base rates of $9 million , or approximately 13% . The $9 million net annual retail electric rate increase reflects a $60 million increase in base rates, partially offset by a $51 million reduction in fuel-related costs, using an estimate for 2017 fuel-related costs. These increases were effective January 1, 2017 and extend through the end of 2018. For the three and nine months ended September 30, 2017 , Alliant Energy and WPL recorded increases in electric base rates of $4 million and $42 million , and increases in gas base rates of $2 million and $6 million , respectively, in conjunction with the base rate increases authorized in the PSCW’s December 2016 order. WPL’s Retail Fuel-related Rate Filing (2016 Test Year) - Pursuant to a 2015 PSCW order, WPL’s 2016 fuel-related costs were subject to deferral if they were outside an annual bandwidth of plus or minus 2% of the approved annual forecasted fuel-related costs. Retail fuel-related costs incurred by WPL in 2016 were lower than fuel-related costs used to determine rates for such period resulting in an over-collection of fuel-related costs. In August 2017, the PSCW authorized WPL to utilize $6 million of the over-collections as an offset to projected 2017 fuel-related cost under-collections. As of September 30, 2017 , $3 million of remaining fuel-related costs for 2016 outside of the approved bandwidth are included in “Commodity cost recovery” in Alliant Energy’s and WPL’s regulatory liabilities table above, and these costs are expected to offset any rate changes for WPL’s 2018 fuel-related costs. WPL’s Retail Fuel-related Rate Filing (2017 Test Year) - In March 2017, WPL filed an application with the PSCW for a mid-year fuel-related cost adjustment for 2017. Fuel-related costs for 2017 are currently expected to exceed the approved 2017 fuel-related cost plan by more than the 2% annual bandwidth. In August 2017, the PSCW authorized WPL to utilize $6 million of the 2016 fuel-related cost over-collections to offset a portion of the projected fuel-related cost under-collections for 2017. As of September 30, 2017 , after applying the 2016 over-recovery amounts, the remaining fuel-related costs for 2017 outside of the approved bandwidth were $3 million and are included in “Other” in Alliant Energy’s and WPL’s regulatory assets table above. WPL’s Retail Fuel-related Rate Filing (2018 Test Year) - In July 2017, WPL filed a request with the PSCW to increase annual rates for WPL’s retail electric customers by $6 million , or approximately 1% , in 2018. The increase primarily reflects a change in expected fuel-related costs in 2018, which are expected to be offset by $3 million of over-collections from WPL’s 2016 fuel-related costs as discussed above. Any rate changes granted from this request are expected to be effective January 1, 2018. |
IPL [Member] | |
Public Utilities, General Disclosures [Line Items] | |
Regulatory Matters | REGULATORY MATTERS Regulatory Assets and Regulatory Liabilities - Regulatory assets were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Tax-related $1,147.9 $1,055.6 $1,107.9 $1,022.4 $40.0 $33.2 Pension and OPEB costs 547.8 578.7 279.3 294.0 268.5 284.7 Asset retirement obligations 107.9 105.9 71.9 64.3 36.0 41.6 EGUs retired early 67.4 41.4 32.9 — 34.5 41.4 Derivatives 49.9 30.7 22.3 10.0 27.6 20.7 Emission allowances 25.6 26.2 25.6 26.2 — — Other 90.0 76.6 51.0 41.9 39.0 34.7 $2,036.5 $1,915.1 $1,590.9 $1,458.8 $445.6 $456.3 Regulatory liabilities were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Cost of removal obligations $412.1 $411.6 $272.9 $269.4 $139.2 $142.2 Electric transmission cost recovery 94.8 72.0 35.9 35.7 58.9 36.3 IPL’s tax benefit riders 45.0 83.5 45.0 83.5 — — Commodity cost recovery 21.2 30.8 15.0 17.8 6.2 13.0 Energy efficiency cost recovery 20.0 20.5 — — 20.0 20.5 Derivatives 10.9 31.5 5.8 12.1 5.1 19.4 Other 24.5 31.1 10.2 12.3 14.3 18.8 $628.5 $681.0 $384.8 $430.8 $243.7 $250.2 Tax-related - Alliant Energy’s and IPL’s tax-related regulatory assets are generally impacted by certain property-related differences at IPL for which deferred tax is not recorded in the income statement pursuant to Iowa rate-making principles. Deferred tax amounts for such property-related differences at IPL are recorded to regulatory assets, along with the necessary revenue requirement tax gross-ups. During the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s tax-related regulatory assets increased primarily due to property-related differences for qualifying repair expenditures. Asset retirement obligations - In September 2017, IPL reached a partial settlement agreement related to its retail electric rate review (2016 Test Year), subject to IUB approval. The proposed settlement does not include the recovery of certain asset retirement obligation costs previously recorded as regulatory assets, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below. Electric generating units retired early - In June 2017, IPL retired Sutherland Units 1 and 3 and reclassified the remaining net book value of these EGUs from property, plant and equipment to a regulatory asset on Alliant Energy’s and IPL’s balance sheets. IPL is currently earning a return on the remaining net book value of these EGUs, as well as recovering the remaining net book value of these EGUs from both its retail and wholesale customers. IPL’s proposed settlement reached in September 2017 includes recovery of the remaining net book value of these EGUs from IPL’s retail customers over a 10 -year period. However, the proposed settlement does not allow IPL to earn a return on the remaining net book value of these EGUs from its retail customers when final rates are implemented, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below. IPL has requested continued recovery of the remaining net book value of these EGUs from its retail customers over a 10 -year period from the IUB, with a decision currently expected in the first quarter of 2018. In September 2017, FERC approved continued recovery of the remaining net book value of these EGUs from IPL’s wholesale customers over a 10 -year period. Derivatives - Refer to Note 11 for discussion of derivative assets and derivative liabilities. Electric transmission cost recovery - A group of MISO cooperative and municipal utilities previously filed two complaints with FERC requesting a reduction to the base return on equity used by MISO transmission owners, including ITC and ATC LLC, to determine electric transmission costs billed to utilities, including IPL and WPL. In September 2016, FERC issued an order on the first complaint and established a base return on equity of 10.32% , excluding any incentive adders granted by FERC, effective September 28, 2016, and for the refund period from November 12, 2013 through February 11, 2015 (first complaint period). During the nine months ended September 30, 2017, Alliant Energy, IPL and WPL received the refunds for the first complaint period of $50 million , $39 million and $11 million , respectively, after final true-ups. IPL and WPL each initially recorded the retail portion of the refunds to a regulatory liability. Pursuant to IUB approval, IPL’s retail portion of the refund from ITC is currently being refunded to its retail customers in 2017. WPL’s retail portion of the refund from ATC LLC will remain in a regulatory liability until such refunds are approved to be returned to retail customers in a future rate proceeding. IPL’s and WPL’s wholesale customers received their share of the refunds through normal monthly billing practices in 2017. IPL’s tax benefit riders - IPL’s tax benefit riders utilize regulatory liabilities to credit bills of IPL’s Iowa retail electric and gas customers to help offset the impact of rate increases on such customers. These regulatory liabilities are related to tax benefits from tax accounting method changes for repairs expenditures and cost of removal expenditures, and a rate-making accounting change for capitalized interest. For the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s “IPL’s tax benefit riders” regulatory liabilities decreased by ($39) million as follows (in millions): Electric tax benefit rider credits ($51 ) Gas tax benefit rider credits (5 ) Rate-making accounting change 17 ($39 ) In the third quarter of 2017, Alliant Energy and IPL implemented a rate-making accounting change for capitalized interest. IPL currently anticipates crediting its related tax benefits from this rate-making accounting change to its Iowa retail electric and gas customers in the future, and as a result, Alliant Energy and IPL recorded an increase of $17 million to IPL’s tax benefit riders regulatory liabilities during the nine months ended September 30, 2017. Utility Rate Reviews - IPL’s Retail Electric Rate Review (2016 Test Year) - In April 2017, IPL filed a request with the IUB to increase annual electric base rates for its Iowa retail electric customers by $176 million , or approximately 12% . The request was based on a 2016 historical Test Year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of capital projects, primarily power grid modernization and investments that advance cleaner energy, including Marshalltown. An interim retail electric base rate increase of $102 million , or approximately 7% , on an annual basis, was implemented effective April 13, 2017, without regulatory review, and will be subject to refund pending determination of final rates. Tax benefit rider credits and MISO transmission owner return on equity refunds are expected to reduce the effect of the rate increase on customer bills in 2017 and 2018. For the three and nine months ended September 30, 2017 , Alliant Energy and IPL recorded increases in electric base rates of $34 million and $54 million , respectively, in conjunction with the interim retail electric base rate increase. In September 2017, IPL reached a partial, non-unanimous settlement agreement with the Iowa Office of Consumer Advocate, the Iowa Business Energy Coalition and the Large Energy Group for an annual electric base rate increase of $130 million , or approximately 9% . The final proposed rate increase (based on proposed settlement) includes increased depreciation expense resulting from an updated depreciation study; recovery over a four -year period of asset retirement obligation expenditures since the last retail electric rate filing in 2010; recovery over a 10 -year period of the remaining net book value of Sutherland Units 1 and 3, unamortized forward contract costs for SO2 emission allowances through the energy adjustment clause and cancelled project costs approved in a prior emissions plan and budget; and no double leverage applied to the weighted-average cost of capital. The proposed settlement did not address rate design or IPL’s proposal to continue the electric transmission cost rider. As a result of the proposed settlement, in the third quarter of 2017, IPL recorded a write-down of regulatory assets of $9 million , including $4 million to “Other operation and maintenance” expenses primarily related to IPL being no longer probable of earning a return on the remaining net book value of Sutherland Units 1 and 3 from its retail customers when final rates are implemented, and $5 million to “Depreciation and amortization” expenses for asset retirement obligations deemed no longer probable of recovery in future rates. IPL currently expects to implement final rates in the first quarter of 2018. The IUB must issue a decision on requests for retail rate changes within 10 months of the date of the application for which changes are filed. |
WPL [Member] | |
Public Utilities, General Disclosures [Line Items] | |
Regulatory Matters | REGULATORY MATTERS Regulatory Assets and Regulatory Liabilities - Regulatory assets were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Tax-related $1,147.9 $1,055.6 $1,107.9 $1,022.4 $40.0 $33.2 Pension and OPEB costs 547.8 578.7 279.3 294.0 268.5 284.7 Asset retirement obligations 107.9 105.9 71.9 64.3 36.0 41.6 EGUs retired early 67.4 41.4 32.9 — 34.5 41.4 Derivatives 49.9 30.7 22.3 10.0 27.6 20.7 Emission allowances 25.6 26.2 25.6 26.2 — — Other 90.0 76.6 51.0 41.9 39.0 34.7 $2,036.5 $1,915.1 $1,590.9 $1,458.8 $445.6 $456.3 Regulatory liabilities were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Cost of removal obligations $412.1 $411.6 $272.9 $269.4 $139.2 $142.2 Electric transmission cost recovery 94.8 72.0 35.9 35.7 58.9 36.3 IPL’s tax benefit riders 45.0 83.5 45.0 83.5 — — Commodity cost recovery 21.2 30.8 15.0 17.8 6.2 13.0 Energy efficiency cost recovery 20.0 20.5 — — 20.0 20.5 Derivatives 10.9 31.5 5.8 12.1 5.1 19.4 Other 24.5 31.1 10.2 12.3 14.3 18.8 $628.5 $681.0 $384.8 $430.8 $243.7 $250.2 Tax-related - Alliant Energy’s and IPL’s tax-related regulatory assets are generally impacted by certain property-related differences at IPL for which deferred tax is not recorded in the income statement pursuant to Iowa rate-making principles. Deferred tax amounts for such property-related differences at IPL are recorded to regulatory assets, along with the necessary revenue requirement tax gross-ups. During the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s tax-related regulatory assets increased primarily due to property-related differences for qualifying repair expenditures. Asset retirement obligations - In September 2017, IPL reached a partial settlement agreement related to its retail electric rate review (2016 Test Year), subject to IUB approval. The proposed settlement does not include the recovery of certain asset retirement obligation costs previously recorded as regulatory assets, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below. Electric generating units retired early - In June 2017, IPL retired Sutherland Units 1 and 3 and reclassified the remaining net book value of these EGUs from property, plant and equipment to a regulatory asset on Alliant Energy’s and IPL’s balance sheets. IPL is currently earning a return on the remaining net book value of these EGUs, as well as recovering the remaining net book value of these EGUs from both its retail and wholesale customers. IPL’s proposed settlement reached in September 2017 includes recovery of the remaining net book value of these EGUs from IPL’s retail customers over a 10 -year period. However, the proposed settlement does not allow IPL to earn a return on the remaining net book value of these EGUs from its retail customers when final rates are implemented, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below. IPL has requested continued recovery of the remaining net book value of these EGUs from its retail customers over a 10 -year period from the IUB, with a decision currently expected in the first quarter of 2018. In September 2017, FERC approved continued recovery of the remaining net book value of these EGUs from IPL’s wholesale customers over a 10 -year period. Derivatives - Refer to Note 11 for discussion of derivative assets and derivative liabilities. Electric transmission cost recovery - A group of MISO cooperative and municipal utilities previously filed two complaints with FERC requesting a reduction to the base return on equity used by MISO transmission owners, including ITC and ATC LLC, to determine electric transmission costs billed to utilities, including IPL and WPL. In September 2016, FERC issued an order on the first complaint and established a base return on equity of 10.32% , excluding any incentive adders granted by FERC, effective September 28, 2016, and for the refund period from November 12, 2013 through February 11, 2015 (first complaint period). During the nine months ended September 30, 2017, Alliant Energy, IPL and WPL received the refunds for the first complaint period of $50 million , $39 million and $11 million , respectively, after final true-ups. IPL and WPL each initially recorded the retail portion of the refunds to a regulatory liability. Pursuant to IUB approval, IPL’s retail portion of the refund from ITC is currently being refunded to its retail customers in 2017. WPL’s retail portion of the refund from ATC LLC will remain in a regulatory liability until such refunds are approved to be returned to retail customers in a future rate proceeding. IPL’s and WPL’s wholesale customers received their share of the refunds through normal monthly billing practices in 2017. IPL’s tax benefit riders - IPL’s tax benefit riders utilize regulatory liabilities to credit bills of IPL’s Iowa retail electric and gas customers to help offset the impact of rate increases on such customers. These regulatory liabilities are related to tax benefits from tax accounting method changes for repairs expenditures and cost of removal expenditures, and a rate-making accounting change for capitalized interest. For the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s “IPL’s tax benefit riders” regulatory liabilities decreased by ($39) million as follows (in millions): Electric tax benefit rider credits ($51 ) Gas tax benefit rider credits (5 ) Rate-making accounting change 17 ($39 ) In the third quarter of 2017, Alliant Energy and IPL implemented a rate-making accounting change for capitalized interest. IPL currently anticipates crediting its related tax benefits from this rate-making accounting change to its Iowa retail electric and gas customers in the future, and as a result, Alliant Energy and IPL recorded an increase of $17 million to IPL’s tax benefit riders regulatory liabilities during the nine months ended September 30, 2017. Utility Rate Reviews - IPL’s Retail Electric Rate Review (2016 Test Year) - In April 2017, IPL filed a request with the IUB to increase annual electric base rates for its Iowa retail electric customers by $176 million , or approximately 12% . The request was based on a 2016 historical Test Year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of capital projects, primarily power grid modernization and investments that advance cleaner energy, including Marshalltown. An interim retail electric base rate increase of $102 million , or approximately 7% , on an annual basis, was implemented effective April 13, 2017, without regulatory review, and will be subject to refund pending determination of final rates. Tax benefit rider credits and MISO transmission owner return on equity refunds are expected to reduce the effect of the rate increase on customer bills in 2017 and 2018. For the three and nine months ended September 30, 2017 , Alliant Energy and IPL recorded increases in electric base rates of $34 million and $54 million , respectively, in conjunction with the interim retail electric base rate increase. In September 2017, IPL reached a partial, non-unanimous settlement agreement with the Iowa Office of Consumer Advocate, the Iowa Business Energy Coalition and the Large Energy Group for an annual electric base rate increase of $130 million , or approximately 9% . The final proposed rate increase (based on proposed settlement) includes increased depreciation expense resulting from an updated depreciation study; recovery over a four -year period of asset retirement obligation expenditures since the last retail electric rate filing in 2010; recovery over a 10 -year period of the remaining net book value of Sutherland Units 1 and 3, unamortized forward contract costs for SO2 emission allowances through the energy adjustment clause and cancelled project costs approved in a prior emissions plan and budget; and no double leverage applied to the weighted-average cost of capital. The proposed settlement did not address rate design or IPL’s proposal to continue the electric transmission cost rider. As a result of the proposed settlement, in the third quarter of 2017, IPL recorded a write-down of regulatory assets of $9 million , including $4 million to “Other operation and maintenance” expenses primarily related to IPL being no longer probable of earning a return on the remaining net book value of Sutherland Units 1 and 3 from its retail customers when final rates are implemented, and $5 million to “Depreciation and amortization” expenses for asset retirement obligations deemed no longer probable of recovery in future rates. IPL currently expects to implement final rates in the first quarter of 2018. The IUB must issue a decision on requests for retail rate changes within 10 months of the date of the application for which changes are filed. WPL’s Retail Electric and Gas Rate Review (2017/2018 Test Period) - In December 2016, WPL received an order from the PSCW authorizing WPL to implement an increase in annual retail electric rates of $9 million , or approximately 1% , and an increase in annual retail gas base rates of $9 million , or approximately 13% . The $9 million net annual retail electric rate increase reflects a $60 million increase in base rates, partially offset by a $51 million reduction in fuel-related costs, using an estimate for 2017 fuel-related costs. These increases were effective January 1, 2017 and extend through the end of 2018. For the three and nine months ended September 30, 2017 , Alliant Energy and WPL recorded increases in electric base rates of $4 million and $42 million , and increases in gas base rates of $2 million and $6 million , respectively, in conjunction with the base rate increases authorized in the PSCW’s December 2016 order. WPL’s Retail Fuel-related Rate Filing (2016 Test Year) - Pursuant to a 2015 PSCW order, WPL’s 2016 fuel-related costs were subject to deferral if they were outside an annual bandwidth of plus or minus 2% of the approved annual forecasted fuel-related costs. Retail fuel-related costs incurred by WPL in 2016 were lower than fuel-related costs used to determine rates for such period resulting in an over-collection of fuel-related costs. In August 2017, the PSCW authorized WPL to utilize $6 million of the over-collections as an offset to projected 2017 fuel-related cost under-collections. As of September 30, 2017 , $3 million of remaining fuel-related costs for 2016 outside of the approved bandwidth are included in “Commodity cost recovery” in Alliant Energy’s and WPL’s regulatory liabilities table above, and these costs are expected to offset any rate changes for WPL’s 2018 fuel-related costs. WPL’s Retail Fuel-related Rate Filing (2017 Test Year) - In March 2017, WPL filed an application with the PSCW for a mid-year fuel-related cost adjustment for 2017. Fuel-related costs for 2017 are currently expected to exceed the approved 2017 fuel-related cost plan by more than the 2% annual bandwidth. In August 2017, the PSCW authorized WPL to utilize $6 million of the 2016 fuel-related cost over-collections to offset a portion of the projected fuel-related cost under-collections for 2017. As of September 30, 2017 , after applying the 2016 over-recovery amounts, the remaining fuel-related costs for 2017 outside of the approved bandwidth were $3 million and are included in “Other” in Alliant Energy’s and WPL’s regulatory assets table above. WPL’s Retail Fuel-related Rate Filing (2018 Test Year) - In July 2017, WPL filed a request with the PSCW to increase annual rates for WPL’s retail electric customers by $6 million , or approximately 1% , in 2018. The increase primarily reflects a change in expected fuel-related costs in 2018, which are expected to be offset by $3 million of over-collections from WPL’s 2016 fuel-related costs as discussed above. Any rate changes granted from this request are expected to be effective January 1, 2018. |
Property, Plant and Equipment
Property, Plant and Equipment | 9 Months Ended |
Sep. 30, 2017 | |
Property, Plant and Equipment [Line Items] | |
Property, Plant and Equipment | PROPERTY, PLANT AND EQUIPMENT Utility - Natural Gas-Fired Generation Projects - IPL’s Marshalltown Generating Station - IPL’s construction of Marshalltown, an approximate 660 MW natural gas-fired combined-cycle EGU, was completed and the EGU was placed into service in April 2017. As of September 30, 2017 , Alliant Energy and IPL recorded total project costs of $643 million and AFUDC of $81 million for Marshalltown in “Property, plant and equipment, net” on their balance sheets. WPL’s West Riverside Energy Center - WPL is currently constructing West Riverside, an approximate 730 MW natural gas-fired combined-cycle EGU. Construction began in 2016 and is currently expected to be completed by early 2020. As of September 30, 2017 , Alliant Energy and WPL recorded capitalized expenditures for construction work in progress of $278 million and AFUDC of $9 million for West Riverside in “Property, plant and equipment, net” on their balance sheets. These capital expenditures do not yet reflect any potential impacts from the exercise of purchase options by certain WPL electric cooperatives for a partial ownership interest in West Riverside. Wind Generation - IPL’s Expansion of Wind Generation - IPL currently plans to add up to 1,000 MW of new wind projects to its existing generation portfolio. These wind projects are expected to be placed into service in 2019 and 2020. As of September 30, 2017 , Alliant Energy and IPL recorded capitalized expenditures for construction work in progress of $184 million and AFUDC of $7 million for this expansion of wind generation in “Property, plant and equipment, net” on their balance sheets. Franklin County Wind Farm - Based on an evaluation of the strategic options for the Franklin County wind farm performed in the third quarter of 2016, Alliant Energy concluded, as of September 30, 2016, it was probable the Franklin County wind farm would be transferred to IPL. As a result, Alliant Energy performed an impairment analysis of such assets and recorded non-cash, pre-tax asset valuation charges of $86 million (after-tax charges of $51 million , or $0.23 per share) in the third quarter of 2016. Alliant Energy recorded such charges as a reduction to property, plant and equipment on its balance sheet in 2016 and charges to “Asset valuation charges for Franklin County wind farm” in its income statements for the three and nine months ended September 30, 2016. The proposed settlement for IPL’s retail electric rate review (2016 Test Year) included recovery of the transfer price for the Franklin County wind farm. In April 2017, the Franklin County wind farm was transferred from AEF to IPL as approved by a February 2017 FERC order. IPL’s purchase price, including certain transaction-related costs, was $32 million . As of the closing date, the estimated fair values of the assets purchased and liabilities assumed by IPL were as follows (in millions): Electric plant in service $40 Current assets 2 Total assets acquired 42 Other liabilities 10 Net assets acquired $32 WPL’s Proposed Acquisition of Forward Wind Energy Center - In October 2017, WPL entered into definitive agreements to acquire the assets of the Forward Wind Energy Center (FWEC), which is a 129 MW wind farm located in Wisconsin. WPL currently expects to acquire 55 MW of FWEC for approximately $74 million . WPL currently expects to file for approval from the PSCW and FERC in the fourth quarter of 2017, with decisions expected by the second quarter of 2018. Retirement of IPL’s Sutherland Units 1 and 3 - In June 2017, IPL retired Sutherland Units 1 and 3 and reclassified the remaining net book value of these EGUs from property, plant and equipment to a regulatory asset on Alliant Energy’s and IPL’s balance sheets. Refer to Note 2 for further discussion. |
IPL [Member] | |
Property, Plant and Equipment [Line Items] | |
Property, Plant and Equipment | PROPERTY, PLANT AND EQUIPMENT Utility - Natural Gas-Fired Generation Projects - IPL’s Marshalltown Generating Station - IPL’s construction of Marshalltown, an approximate 660 MW natural gas-fired combined-cycle EGU, was completed and the EGU was placed into service in April 2017. As of September 30, 2017 , Alliant Energy and IPL recorded total project costs of $643 million and AFUDC of $81 million for Marshalltown in “Property, plant and equipment, net” on their balance sheets. WPL’s West Riverside Energy Center - WPL is currently constructing West Riverside, an approximate 730 MW natural gas-fired combined-cycle EGU. Construction began in 2016 and is currently expected to be completed by early 2020. As of September 30, 2017 , Alliant Energy and WPL recorded capitalized expenditures for construction work in progress of $278 million and AFUDC of $9 million for West Riverside in “Property, plant and equipment, net” on their balance sheets. These capital expenditures do not yet reflect any potential impacts from the exercise of purchase options by certain WPL electric cooperatives for a partial ownership interest in West Riverside. Wind Generation - IPL’s Expansion of Wind Generation - IPL currently plans to add up to 1,000 MW of new wind projects to its existing generation portfolio. These wind projects are expected to be placed into service in 2019 and 2020. As of September 30, 2017 , Alliant Energy and IPL recorded capitalized expenditures for construction work in progress of $184 million and AFUDC of $7 million for this expansion of wind generation in “Property, plant and equipment, net” on their balance sheets. Franklin County Wind Farm - Based on an evaluation of the strategic options for the Franklin County wind farm performed in the third quarter of 2016, Alliant Energy concluded, as of September 30, 2016, it was probable the Franklin County wind farm would be transferred to IPL. As a result, Alliant Energy performed an impairment analysis of such assets and recorded non-cash, pre-tax asset valuation charges of $86 million (after-tax charges of $51 million , or $0.23 per share) in the third quarter of 2016. Alliant Energy recorded such charges as a reduction to property, plant and equipment on its balance sheet in 2016 and charges to “Asset valuation charges for Franklin County wind farm” in its income statements for the three and nine months ended September 30, 2016. The proposed settlement for IPL’s retail electric rate review (2016 Test Year) included recovery of the transfer price for the Franklin County wind farm. In April 2017, the Franklin County wind farm was transferred from AEF to IPL as approved by a February 2017 FERC order. IPL’s purchase price, including certain transaction-related costs, was $32 million . As of the closing date, the estimated fair values of the assets purchased and liabilities assumed by IPL were as follows (in millions): Electric plant in service $40 Current assets 2 Total assets acquired 42 Other liabilities 10 Net assets acquired $32 WPL’s Proposed Acquisition of Forward Wind Energy Center - In October 2017, WPL entered into definitive agreements to acquire the assets of the Forward Wind Energy Center (FWEC), which is a 129 MW wind farm located in Wisconsin. WPL currently expects to acquire 55 MW of FWEC for approximately $74 million . WPL currently expects to file for approval from the PSCW and FERC in the fourth quarter of 2017, with decisions expected by the second quarter of 2018. Retirement of IPL’s Sutherland Units 1 and 3 - In June 2017, IPL retired Sutherland Units 1 and 3 and reclassified the remaining net book value of these EGUs from property, plant and equipment to a regulatory asset on Alliant Energy’s and IPL’s balance sheets. Refer to Note 2 for further discussion. |
WPL [Member] | |
Property, Plant and Equipment [Line Items] | |
Property, Plant and Equipment | PROPERTY, PLANT AND EQUIPMENT Utility - Natural Gas-Fired Generation Projects - IPL’s Marshalltown Generating Station - IPL’s construction of Marshalltown, an approximate 660 MW natural gas-fired combined-cycle EGU, was completed and the EGU was placed into service in April 2017. As of September 30, 2017 , Alliant Energy and IPL recorded total project costs of $643 million and AFUDC of $81 million for Marshalltown in “Property, plant and equipment, net” on their balance sheets. WPL’s West Riverside Energy Center - WPL is currently constructing West Riverside, an approximate 730 MW natural gas-fired combined-cycle EGU. Construction began in 2016 and is currently expected to be completed by early 2020. As of September 30, 2017 , Alliant Energy and WPL recorded capitalized expenditures for construction work in progress of $278 million and AFUDC of $9 million for West Riverside in “Property, plant and equipment, net” on their balance sheets. These capital expenditures do not yet reflect any potential impacts from the exercise of purchase options by certain WPL electric cooperatives for a partial ownership interest in West Riverside. Wind Generation - IPL’s Expansion of Wind Generation - IPL currently plans to add up to 1,000 MW of new wind projects to its existing generation portfolio. These wind projects are expected to be placed into service in 2019 and 2020. As of September 30, 2017 , Alliant Energy and IPL recorded capitalized expenditures for construction work in progress of $184 million and AFUDC of $7 million for this expansion of wind generation in “Property, plant and equipment, net” on their balance sheets. Franklin County Wind Farm - Based on an evaluation of the strategic options for the Franklin County wind farm performed in the third quarter of 2016, Alliant Energy concluded, as of September 30, 2016, it was probable the Franklin County wind farm would be transferred to IPL. As a result, Alliant Energy performed an impairment analysis of such assets and recorded non-cash, pre-tax asset valuation charges of $86 million (after-tax charges of $51 million , or $0.23 per share) in the third quarter of 2016. Alliant Energy recorded such charges as a reduction to property, plant and equipment on its balance sheet in 2016 and charges to “Asset valuation charges for Franklin County wind farm” in its income statements for the three and nine months ended September 30, 2016. The proposed settlement for IPL’s retail electric rate review (2016 Test Year) included recovery of the transfer price for the Franklin County wind farm. In April 2017, the Franklin County wind farm was transferred from AEF to IPL as approved by a February 2017 FERC order. IPL’s purchase price, including certain transaction-related costs, was $32 million . As of the closing date, the estimated fair values of the assets purchased and liabilities assumed by IPL were as follows (in millions): Electric plant in service $40 Current assets 2 Total assets acquired 42 Other liabilities 10 Net assets acquired $32 WPL’s Proposed Acquisition of Forward Wind Energy Center - In October 2017, WPL entered into definitive agreements to acquire the assets of the Forward Wind Energy Center (FWEC), which is a 129 MW wind farm located in Wisconsin. WPL currently expects to acquire 55 MW of FWEC for approximately $74 million . WPL currently expects to file for approval from the PSCW and FERC in the fourth quarter of 2017, with decisions expected by the second quarter of 2018. |
Receivables
Receivables | 9 Months Ended |
Sep. 30, 2017 | |
Receivables [Line Items] | |
Receivables | RECEIVABLES Sales of Accounts Receivable - IPL maintains a Receivables Purchase and Sale Agreement (Receivables Agreement) whereby it may sell its customer accounts receivables, unbilled revenues and certain other accounts receivables to a third party through wholly-owned and consolidated special purpose entities. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. As of September 30, 2017 , IPL had $1.5 million of available capacity under its sales of accounts receivable program. For the three and nine months ended September 30 , 2017 and 2016 , IPL’s costs incurred related to the sales of accounts receivable program were not material. IPL’s maximum and average outstanding cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Maximum outstanding aggregate cash proceeds $112.0 $172.0 $112.0 $172.0 Average outstanding aggregate cash proceeds 66.2 112.3 58.7 91.5 The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2017 December 31, 2016 Customer accounts receivable $153.6 $157.6 Unbilled utility revenues 89.1 90.4 Other receivables 1.1 0.1 Receivables sold to third party 243.8 248.1 Less: cash proceeds (a) 112.0 21.0 Deferred proceeds 131.8 227.1 Less: allowance for doubtful accounts 16.5 16.0 Fair value of deferred proceeds $115.3 $211.1 (a) Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements. As of September 30, 2017 , outstanding receivables past due under the Receivables Agreement were $54.1 million . Additional attributes of IPL’s receivables sold under the Receivables Agreement for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Collections reinvested in receivables $347.9 $499.7 $1,283.2 $1,362.1 Write-off losses (recoveries), net 3.5 (0.3 ) 10.4 (0.6 ) In connection with the implementation of IPL’s new customer billing and information system in 2016, IPL postponed the write-off of customer bills for a portion of 2016, resulting in lower write-offs for the three and nine months ended September 30 , 2016. |
IPL [Member] | |
Receivables [Line Items] | |
Receivables | RECEIVABLES Sales of Accounts Receivable - IPL maintains a Receivables Purchase and Sale Agreement (Receivables Agreement) whereby it may sell its customer accounts receivables, unbilled revenues and certain other accounts receivables to a third party through wholly-owned and consolidated special purpose entities. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. As of September 30, 2017 , IPL had $1.5 million of available capacity under its sales of accounts receivable program. For the three and nine months ended September 30 , 2017 and 2016 , IPL’s costs incurred related to the sales of accounts receivable program were not material. IPL’s maximum and average outstanding cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Maximum outstanding aggregate cash proceeds $112.0 $172.0 $112.0 $172.0 Average outstanding aggregate cash proceeds 66.2 112.3 58.7 91.5 The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2017 December 31, 2016 Customer accounts receivable $153.6 $157.6 Unbilled utility revenues 89.1 90.4 Other receivables 1.1 0.1 Receivables sold to third party 243.8 248.1 Less: cash proceeds (a) 112.0 21.0 Deferred proceeds 131.8 227.1 Less: allowance for doubtful accounts 16.5 16.0 Fair value of deferred proceeds $115.3 $211.1 (a) Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements. As of September 30, 2017 , outstanding receivables past due under the Receivables Agreement were $54.1 million . Additional attributes of IPL’s receivables sold under the Receivables Agreement for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Collections reinvested in receivables $347.9 $499.7 $1,283.2 $1,362.1 Write-off losses (recoveries), net 3.5 (0.3 ) 10.4 (0.6 ) In connection with the implementation of IPL’s new customer billing and information system in 2016, IPL postponed the write-off of customer bills for a portion of 2016, resulting in lower write-offs for the three and nine months ended September 30 , 2016. |
Investments
Investments | 9 Months Ended |
Sep. 30, 2017 | |
Schedule of Investments [Line Items] | |
Investments | INVESTMENTS NOTE 5(a) Unconsolidated Equity Investments - Equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and nine months ended September 30 was as follows (in millions): Alliant Energy WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 ATC Investment ($10.1 ) ($9.1 ) ($32.7 ) ($28.6 ) $— ($9.1 ) $— ($28.6 ) Other — (0.1 ) (0.2 ) (0.2 ) (0.2 ) (0.2 ) (0.4 ) (0.4 ) ($10.1 ) ($9.2 ) ($32.9 ) ($28.8 ) ($0.2 ) ($9.3 ) ($0.4 ) ($29.0 ) ATC Investment - On December 31, 2016, pursuant to a June 2016 PSCW order, WPL Transco, LLC was liquidated and WPL transferred its investment in ATC LLC to ATI. As a result, WPL no longer records equity income from its prior investment in ATC LLC. There were no impacts of this transfer to Alliant Energy’s consolidated financial statements. As of December 31, 2016, ATI owns Alliant Energy’s entire investment in ATC. Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a 50% cash equity ownership interest in a 225 MW non-regulated wind farm located in Oklahoma, which started commercial operations in December 2016. The wind farm provides electricity to a third-party under a long-term purchased power agreement. In the third quarter of 2017, Alliant Energy’s “Other investments” assets increased $98 million from this acquisition. Alliant Energy will not maintain or operate the wind farm, and provided a parent guarantee of its subsidiary’s indemnification obligations under the operating agreement and purchased power agreement. Refer to Note 12(d) for discussion of the guarantee. Alliant Energy accounts for this non-regulated investment under the equity method of accounting, with the related equity (income) loss from unconsolidated investments included in the “Other” line in the above table. In conjunction with the acquisition, in July 2017, AEF entered into a $95 million , 364 -day variable-rate term loan credit agreement (with Alliant Energy as guarantor). NOTE 5(b) Cash Surrender Value of Life Insurance Policies - During the nine months ended September 30 , 2016, certain of Alliant Energy’s and IPL’s company-owned life insurance policies were liquidated. The related proceeds of $31 million and $19 million were recorded in investing activities in Alliant Energy’s and IPL’s cash flows statements, respectively. |
IPL [Member] | |
Schedule of Investments [Line Items] | |
Investments | INVESTMENTS NOTE 5(a) Unconsolidated Equity Investments - Equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and nine months ended September 30 was as follows (in millions): Alliant Energy WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 ATC Investment ($10.1 ) ($9.1 ) ($32.7 ) ($28.6 ) $— ($9.1 ) $— ($28.6 ) Other — (0.1 ) (0.2 ) (0.2 ) (0.2 ) (0.2 ) (0.4 ) (0.4 ) ($10.1 ) ($9.2 ) ($32.9 ) ($28.8 ) ($0.2 ) ($9.3 ) ($0.4 ) ($29.0 ) ATC Investment - On December 31, 2016, pursuant to a June 2016 PSCW order, WPL Transco, LLC was liquidated and WPL transferred its investment in ATC LLC to ATI. As a result, WPL no longer records equity income from its prior investment in ATC LLC. There were no impacts of this transfer to Alliant Energy’s consolidated financial statements. As of December 31, 2016, ATI owns Alliant Energy’s entire investment in ATC. Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a 50% cash equity ownership interest in a 225 MW non-regulated wind farm located in Oklahoma, which started commercial operations in December 2016. The wind farm provides electricity to a third-party under a long-term purchased power agreement. In the third quarter of 2017, Alliant Energy’s “Other investments” assets increased $98 million from this acquisition. Alliant Energy will not maintain or operate the wind farm, and provided a parent guarantee of its subsidiary’s indemnification obligations under the operating agreement and purchased power agreement. Refer to Note 12(d) for discussion of the guarantee. Alliant Energy accounts for this non-regulated investment under the equity method of accounting, with the related equity (income) loss from unconsolidated investments included in the “Other” line in the above table. In conjunction with the acquisition, in July 2017, AEF entered into a $95 million , 364 -day variable-rate term loan credit agreement (with Alliant Energy as guarantor). NOTE 5(b) Cash Surrender Value of Life Insurance Policies - During the nine months ended September 30 , 2016, certain of Alliant Energy’s and IPL’s company-owned life insurance policies were liquidated. The related proceeds of $31 million and $19 million were recorded in investing activities in Alliant Energy’s and IPL’s cash flows statements, respectively. |
WPL [Member] | |
Schedule of Investments [Line Items] | |
Investments | INVESTMENTS NOTE 5(a) Unconsolidated Equity Investments - Equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and nine months ended September 30 was as follows (in millions): Alliant Energy WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 ATC Investment ($10.1 ) ($9.1 ) ($32.7 ) ($28.6 ) $— ($9.1 ) $— ($28.6 ) Other — (0.1 ) (0.2 ) (0.2 ) (0.2 ) (0.2 ) (0.4 ) (0.4 ) ($10.1 ) ($9.2 ) ($32.9 ) ($28.8 ) ($0.2 ) ($9.3 ) ($0.4 ) ($29.0 ) ATC Investment - On December 31, 2016, pursuant to a June 2016 PSCW order, WPL Transco, LLC was liquidated and WPL transferred its investment in ATC LLC to ATI. As a result, WPL no longer records equity income from its prior investment in ATC LLC. There were no impacts of this transfer to Alliant Energy’s consolidated financial statements. As of December 31, 2016, ATI owns Alliant Energy’s entire investment in ATC. |
Common Equity
Common Equity | 9 Months Ended |
Sep. 30, 2017 | |
Common Equity [Line Items] | |
Common Equity | COMMON EQUITY Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows: Shares outstanding, January 1, 2017 227,673,654 At-the-market offering program 3,074,931 Shareowner Direct Plan issuances 496,437 Equity-based compensation plans ( Note 9(b) ) 5,185 Other (45,847 ) Shares outstanding, September 30, 2017 231,204,360 At-the-Market Offering Program - In May 2017, Alliant Energy filed a prospectus supplement under which it could sell up to $125 million of its common stock through an at-the-market offering program. As of September 30, 2017 , Alliant Energy issued 3,074,931 shares of common stock through this program and received cash proceeds of $124 million , net of $1 million in commissions and fees. The proceeds from the issuances of common stock were used for general corporate purposes. Alliant Energy currently has no plans to issue any additional common stock through this at-the-market offering program. Dividend Restrictions - As of September 30, 2017 , IPL’s amount of retained earnings that were free of dividend restrictions was $701 million . As of September 30, 2017 , WPL’s amount of retained earnings that were free of dividend restrictions was $32 million for the remainder of 2017 . Restricted Net Assets of Subsidiaries - As of September 30, 2017 , the amount of IPL’s and WPL’s net assets that were not available to be transferred to their parent company, Alliant Energy, in the form of loans, advances or cash dividends without the consent of IPL’s and WPL’s regulatory authorities was $1.7 billion and $1.8 billion , respectively. Comprehensive Income - For the three and nine months ended September 30, 2017 and 2016 , Alliant Energy had no other comprehensive income; therefore, its comprehensive income was equal to its net income and its comprehensive income attributable to Alliant Energy common shareowners was equal to its net income attributable to Alliant Energy common shareowners for such periods. For the three and nine months ended September 30, 2017 and 2016 , IPL and WPL had no other comprehensive income; therefore, their comprehensive income was equal to their net income and their comprehensive income available for common stock was equal to their earnings available for common stock for such periods. |
IPL [Member] | |
Common Equity [Line Items] | |
Common Equity | COMMON EQUITY Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows: Shares outstanding, January 1, 2017 227,673,654 At-the-market offering program 3,074,931 Shareowner Direct Plan issuances 496,437 Equity-based compensation plans ( Note 9(b) ) 5,185 Other (45,847 ) Shares outstanding, September 30, 2017 231,204,360 At-the-Market Offering Program - In May 2017, Alliant Energy filed a prospectus supplement under which it could sell up to $125 million of its common stock through an at-the-market offering program. As of September 30, 2017 , Alliant Energy issued 3,074,931 shares of common stock through this program and received cash proceeds of $124 million , net of $1 million in commissions and fees. The proceeds from the issuances of common stock were used for general corporate purposes. Alliant Energy currently has no plans to issue any additional common stock through this at-the-market offering program. Dividend Restrictions - As of September 30, 2017 , IPL’s amount of retained earnings that were free of dividend restrictions was $701 million . As of September 30, 2017 , WPL’s amount of retained earnings that were free of dividend restrictions was $32 million for the remainder of 2017 . Restricted Net Assets of Subsidiaries - As of September 30, 2017 , the amount of IPL’s and WPL’s net assets that were not available to be transferred to their parent company, Alliant Energy, in the form of loans, advances or cash dividends without the consent of IPL’s and WPL’s regulatory authorities was $1.7 billion and $1.8 billion , respectively. Comprehensive Income - For the three and nine months ended September 30, 2017 and 2016 , Alliant Energy had no other comprehensive income; therefore, its comprehensive income was equal to its net income and its comprehensive income attributable to Alliant Energy common shareowners was equal to its net income attributable to Alliant Energy common shareowners for such periods. For the three and nine months ended September 30, 2017 and 2016 , IPL and WPL had no other comprehensive income; therefore, their comprehensive income was equal to their net income and their comprehensive income available for common stock was equal to their earnings available for common stock for such periods. |
WPL [Member] | |
Common Equity [Line Items] | |
Common Equity | COMMON EQUITY Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows: Shares outstanding, January 1, 2017 227,673,654 At-the-market offering program 3,074,931 Shareowner Direct Plan issuances 496,437 Equity-based compensation plans ( Note 9(b) ) 5,185 Other (45,847 ) Shares outstanding, September 30, 2017 231,204,360 At-the-Market Offering Program - In May 2017, Alliant Energy filed a prospectus supplement under which it could sell up to $125 million of its common stock through an at-the-market offering program. As of September 30, 2017 , Alliant Energy issued 3,074,931 shares of common stock through this program and received cash proceeds of $124 million , net of $1 million in commissions and fees. The proceeds from the issuances of common stock were used for general corporate purposes. Alliant Energy currently has no plans to issue any additional common stock through this at-the-market offering program. Dividend Restrictions - As of September 30, 2017 , IPL’s amount of retained earnings that were free of dividend restrictions was $701 million . As of September 30, 2017 , WPL’s amount of retained earnings that were free of dividend restrictions was $32 million for the remainder of 2017 . Restricted Net Assets of Subsidiaries - As of September 30, 2017 , the amount of IPL’s and WPL’s net assets that were not available to be transferred to their parent company, Alliant Energy, in the form of loans, advances or cash dividends without the consent of IPL’s and WPL’s regulatory authorities was $1.7 billion and $1.8 billion , respectively. Comprehensive Income - For the three and nine months ended September 30, 2017 and 2016 , Alliant Energy had no other comprehensive income; therefore, its comprehensive income was equal to its net income and its comprehensive income attributable to Alliant Energy common shareowners was equal to its net income attributable to Alliant Energy common shareowners for such periods. For the three and nine months ended September 30, 2017 and 2016 , IPL and WPL had no other comprehensive income; therefore, their comprehensive income was equal to their net income and their comprehensive income available for common stock was equal to their earnings available for common stock for such periods. |
Debt
Debt | 9 Months Ended |
Sep. 30, 2017 | |
Debt [Line Items] | |
Debt | DEBT Note 7(a) Short-term Debt - In August 2017, Alliant Energy, IPL and WPL entered into a single new credit facility agreement, which expires in August 2022. The new credit facility agreement includes financial covenants similar to those that were included in the previous credit facility agreements. As of September 30, 2017 , the short-term borrowing capacity under the new credit facility agreement totaled $1 billion ( $300 million for Alliant Energy at the parent company level, $300 million for IPL and $400 million for WPL). Subject to certain conditions, Alliant Energy (at the parent company level), IPL and WPL may each reallocate and change its initial sublimit up to $500 million , $400 million and $500 million , respectively, within the $1 billion total commitment. Information regarding commercial paper classified as short-term debt was as follows (dollars in millions): September 30, 2017 Alliant Energy IPL WPL Commercial paper outstanding $390.3 $4.0 $224.6 Commercial paper weighted average interest rates 1.2% 1.4% 1.1% Available credit facility capacity (a) $569.7 $256.0 $175.4 Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $55.4 Average amount outstanding (based on daily outstanding balances) $386.2 $220.1 $0.4 $0.1 $217.0 $36.4 Weighted average interest rates 1.3% 0.6% 1.4% 0.6% 1.1% 0.4% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $62.9 Average amount outstanding (based on daily outstanding balances) $323.9 $210.7 $0.5 $— $144.2 $33.2 Weighted average interest rates 1.1% 0.6% 1.2% 0.6% 1.0% 0.4% (a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017 . In July 2017, AEF entered into a $95 million , 364 -day variable-rate ( 1.8% at September 30, 2017 ) term loan credit agreement (with Alliant Energy as guarantor) related to the acquisition of a non-regulated wind farm located in Oklahoma, which includes substantially the same financial covenants that are included in Alliant Energy’s current credit facility agreement. Refer to Note 5(a) for further discussion of the non-regulated wind farm acquisition. NOTE 7(b) Long-term Debt - As of September 30, 2017 , $40.0 million of commercial paper was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s balance sheets due to the existence of a long-term credit facility that back-stops this commercial paper balance, along with Alliant Energy’s and IPL’s intent and ability to refinance these balances on a long-term basis. As of September 30, 2017 , this commercial paper balance had a 1.4% interest rate. In October 2017, WPL issued $300 million of 3.05% debentures due 2027. The proceeds from the issuance were used by WPL to reduce commercial paper and for general corporate purposes. |
IPL [Member] | |
Debt [Line Items] | |
Debt | DEBT Note 7(a) Short-term Debt - In August 2017, Alliant Energy, IPL and WPL entered into a single new credit facility agreement, which expires in August 2022. The new credit facility agreement includes financial covenants similar to those that were included in the previous credit facility agreements. As of September 30, 2017 , the short-term borrowing capacity under the new credit facility agreement totaled $1 billion ( $300 million for Alliant Energy at the parent company level, $300 million for IPL and $400 million for WPL). Subject to certain conditions, Alliant Energy (at the parent company level), IPL and WPL may each reallocate and change its initial sublimit up to $500 million , $400 million and $500 million , respectively, within the $1 billion total commitment. Information regarding commercial paper classified as short-term debt was as follows (dollars in millions): September 30, 2017 Alliant Energy IPL WPL Commercial paper outstanding $390.3 $4.0 $224.6 Commercial paper weighted average interest rates 1.2% 1.4% 1.1% Available credit facility capacity (a) $569.7 $256.0 $175.4 Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $55.4 Average amount outstanding (based on daily outstanding balances) $386.2 $220.1 $0.4 $0.1 $217.0 $36.4 Weighted average interest rates 1.3% 0.6% 1.4% 0.6% 1.1% 0.4% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $62.9 Average amount outstanding (based on daily outstanding balances) $323.9 $210.7 $0.5 $— $144.2 $33.2 Weighted average interest rates 1.1% 0.6% 1.2% 0.6% 1.0% 0.4% (a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017 . In July 2017, AEF entered into a $95 million , 364 -day variable-rate ( 1.8% at September 30, 2017 ) term loan credit agreement (with Alliant Energy as guarantor) related to the acquisition of a non-regulated wind farm located in Oklahoma, which includes substantially the same financial covenants that are included in Alliant Energy’s current credit facility agreement. Refer to Note 5(a) for further discussion of the non-regulated wind farm acquisition. NOTE 7(b) Long-term Debt - As of September 30, 2017 , $40.0 million of commercial paper was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s balance sheets due to the existence of a long-term credit facility that back-stops this commercial paper balance, along with Alliant Energy’s and IPL’s intent and ability to refinance these balances on a long-term basis. As of September 30, 2017 , this commercial paper balance had a 1.4% interest rate. |
WPL [Member] | |
Debt [Line Items] | |
Debt | DEBT Note 7(a) Short-term Debt - In August 2017, Alliant Energy, IPL and WPL entered into a single new credit facility agreement, which expires in August 2022. The new credit facility agreement includes financial covenants similar to those that were included in the previous credit facility agreements. As of September 30, 2017 , the short-term borrowing capacity under the new credit facility agreement totaled $1 billion ( $300 million for Alliant Energy at the parent company level, $300 million for IPL and $400 million for WPL). Subject to certain conditions, Alliant Energy (at the parent company level), IPL and WPL may each reallocate and change its initial sublimit up to $500 million , $400 million and $500 million , respectively, within the $1 billion total commitment. Information regarding commercial paper classified as short-term debt was as follows (dollars in millions): September 30, 2017 Alliant Energy IPL WPL Commercial paper outstanding $390.3 $4.0 $224.6 Commercial paper weighted average interest rates 1.2% 1.4% 1.1% Available credit facility capacity (a) $569.7 $256.0 $175.4 Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $55.4 Average amount outstanding (based on daily outstanding balances) $386.2 $220.1 $0.4 $0.1 $217.0 $36.4 Weighted average interest rates 1.3% 0.6% 1.4% 0.6% 1.1% 0.4% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $62.9 Average amount outstanding (based on daily outstanding balances) $323.9 $210.7 $0.5 $— $144.2 $33.2 Weighted average interest rates 1.1% 0.6% 1.2% 0.6% 1.0% 0.4% (a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017 . In July 2017, AEF entered into a $95 million , 364 -day variable-rate ( 1.8% at September 30, 2017 ) term loan credit agreement (with Alliant Energy as guarantor) related to the acquisition of a non-regulated wind farm located in Oklahoma, which includes substantially the same financial covenants that are included in Alliant Energy’s current credit facility agreement. Refer to Note 5(a) for further discussion of the non-regulated wind farm acquisition. NOTE 7(b) Long-term Debt - As of September 30, 2017 , $40.0 million of commercial paper was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s balance sheets due to the existence of a long-term credit facility that back-stops this commercial paper balance, along with Alliant Energy’s and IPL’s intent and ability to refinance these balances on a long-term basis. As of September 30, 2017 , this commercial paper balance had a 1.4% interest rate. In October 2017, WPL issued $300 million of 3.05% debentures due 2027. The proceeds from the issuance were used by WPL to reduce commercial paper and for general corporate purposes. |
Income Taxes
Income Taxes | 9 Months Ended |
Sep. 30, 2017 | |
Income Taxes [Line Items] | |
Income Taxes | INCOME TAXES Income Tax Rates - The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes. Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (10.1 ) (11.9 ) (22.6 ) (16.5 ) (1.9 ) (0.7 ) IPL’s tax benefit riders (8.3 ) (13.1 ) (20.9 ) (20.1 ) — — Production tax credits (6.2 ) (9.0 ) (7.0 ) (6.0 ) (7.0 ) (5.7 ) Other items, net 2.8 4.4 2.3 5.4 5.5 4.0 Overall income tax rate 13.2 % 5.4 % (13.2 %) (2.2 %) 31.6 % 32.6 % Alliant Energy IPL WPL Nine Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (9.1 ) (8.2 ) (20.6 ) (14.8 ) (1.8 ) (0.8 ) IPL’s tax benefit riders (8.1 ) (10.2 ) (20.1 ) (19.6 ) — — Production tax credits (6.0 ) (7.2 ) (6.8 ) (6.1 ) (7.0 ) (6.1 ) Other items, net 3.1 3.5 2.7 4.2 4.9 4.4 Overall income tax rate 14.9 % 12.9 % (9.8 %) (1.3 %) 31.1 % 32.5 % Deferred Tax Assets and Liabilities - For the nine months ended September 30 , 2017 , Alliant Energy’s, IPL’s and WPL’s deferred tax liabilities increased $204.5 million , $131.7 million and $63.6 million , respectively. These increases were primarily due to property-related differences recorded during the nine months ended September 30 , 2017 . Alliant Energy’s and IPL’s increases were partially offset by the generation of federal net operating losses recorded during the nine months ended September 30 , 2017 , which are primarily due to accelerated tax depreciation associated with Marshalltown. Carryforwards - At September 30, 2017 , carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2030-2037 $815 $500 $208 State net operating losses 2018-2037 701 14 2 Federal tax credits 2022-2037 297 110 125 |
IPL [Member] | |
Income Taxes [Line Items] | |
Income Taxes | INCOME TAXES Income Tax Rates - The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes. Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (10.1 ) (11.9 ) (22.6 ) (16.5 ) (1.9 ) (0.7 ) IPL’s tax benefit riders (8.3 ) (13.1 ) (20.9 ) (20.1 ) — — Production tax credits (6.2 ) (9.0 ) (7.0 ) (6.0 ) (7.0 ) (5.7 ) Other items, net 2.8 4.4 2.3 5.4 5.5 4.0 Overall income tax rate 13.2 % 5.4 % (13.2 %) (2.2 %) 31.6 % 32.6 % Alliant Energy IPL WPL Nine Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (9.1 ) (8.2 ) (20.6 ) (14.8 ) (1.8 ) (0.8 ) IPL’s tax benefit riders (8.1 ) (10.2 ) (20.1 ) (19.6 ) — — Production tax credits (6.0 ) (7.2 ) (6.8 ) (6.1 ) (7.0 ) (6.1 ) Other items, net 3.1 3.5 2.7 4.2 4.9 4.4 Overall income tax rate 14.9 % 12.9 % (9.8 %) (1.3 %) 31.1 % 32.5 % Deferred Tax Assets and Liabilities - For the nine months ended September 30 , 2017 , Alliant Energy’s, IPL’s and WPL’s deferred tax liabilities increased $204.5 million , $131.7 million and $63.6 million , respectively. These increases were primarily due to property-related differences recorded during the nine months ended September 30 , 2017 . Alliant Energy’s and IPL’s increases were partially offset by the generation of federal net operating losses recorded during the nine months ended September 30 , 2017 , which are primarily due to accelerated tax depreciation associated with Marshalltown. Carryforwards - At September 30, 2017 , carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2030-2037 $815 $500 $208 State net operating losses 2018-2037 701 14 2 Federal tax credits 2022-2037 297 110 125 |
WPL [Member] | |
Income Taxes [Line Items] | |
Income Taxes | INCOME TAXES Income Tax Rates - The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes. Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (10.1 ) (11.9 ) (22.6 ) (16.5 ) (1.9 ) (0.7 ) IPL’s tax benefit riders (8.3 ) (13.1 ) (20.9 ) (20.1 ) — — Production tax credits (6.2 ) (9.0 ) (7.0 ) (6.0 ) (7.0 ) (5.7 ) Other items, net 2.8 4.4 2.3 5.4 5.5 4.0 Overall income tax rate 13.2 % 5.4 % (13.2 %) (2.2 %) 31.6 % 32.6 % Alliant Energy IPL WPL Nine Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (9.1 ) (8.2 ) (20.6 ) (14.8 ) (1.8 ) (0.8 ) IPL’s tax benefit riders (8.1 ) (10.2 ) (20.1 ) (19.6 ) — — Production tax credits (6.0 ) (7.2 ) (6.8 ) (6.1 ) (7.0 ) (6.1 ) Other items, net 3.1 3.5 2.7 4.2 4.9 4.4 Overall income tax rate 14.9 % 12.9 % (9.8 %) (1.3 %) 31.1 % 32.5 % Deferred Tax Assets and Liabilities - For the nine months ended September 30 , 2017 , Alliant Energy’s, IPL’s and WPL’s deferred tax liabilities increased $204.5 million , $131.7 million and $63.6 million , respectively. These increases were primarily due to property-related differences recorded during the nine months ended September 30 , 2017 . Alliant Energy’s and IPL’s increases were partially offset by the generation of federal net operating losses recorded during the nine months ended September 30 , 2017 , which are primarily due to accelerated tax depreciation associated with Marshalltown. Carryforwards - At September 30, 2017 , carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2030-2037 $815 $500 $208 State net operating losses 2018-2037 701 14 2 Federal tax credits 2022-2037 297 110 125 |
Benefit Plans
Benefit Plans | 9 Months Ended |
Sep. 30, 2017 | |
Benefit Plans | BENEFIT PLANS NOTE 9(a) Pension and Other Postretirement Benefits Plans - Net Periodic Benefit Costs - The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and nine months ended September 30 are included in the tables below (in millions). In IPL’s and WPL’s tables below, the defined benefit pension plan amounts represent those respective amounts for their bargaining unit employees covered under the qualified plans that they sponsor, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans. In IPL’s and WPL’s tables below, the OPEB plans amounts represent respective amounts for their employees, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Corporate Services sponsored OPEB plan. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $3.1 $3.2 $9.3 $9.5 $1.2 $1.4 $3.7 $4.0 Interest cost 12.7 13.2 38.3 39.7 2.2 2.3 6.5 7.0 Expected return on plan assets (16.3 ) (16.3 ) (49.1 ) (49.1 ) (1.5 ) (1.6 ) (4.6 ) (4.6 ) Amortization of prior service credit (0.1 ) (0.1 ) (0.3 ) (0.2 ) (0.1 ) (1.0 ) (0.2 ) (3.1 ) Amortization of actuarial loss 9.4 9.3 28.2 28.0 1.0 1.2 2.9 3.6 Settlement losses (a) 0.9 — 0.9 — — — — — $9.7 $9.3 $27.3 $27.9 $2.8 $2.3 $8.3 $6.9 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.8 $1.8 $5.5 $5.6 $0.5 $0.5 $1.6 $1.7 Interest cost 5.9 6.1 17.6 18.4 0.8 1.0 2.6 2.9 Expected return on plan assets (7.7 ) (7.7 ) (23.1 ) (23.2 ) (1.0 ) (1.0 ) (3.2 ) (3.2 ) Amortization of prior service credit — — (0.1 ) (0.1 ) — (0.7 ) — (2.0 ) Amortization of actuarial loss 4.0 4.2 12.1 12.4 0.5 0.7 1.5 2.0 $4.0 $4.4 $12.0 $13.1 $0.8 $0.5 $2.5 $1.4 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.2 $1.3 $3.6 $3.7 $0.5 $0.5 $1.4 $1.5 Interest cost 5.5 5.5 16.4 16.7 0.9 0.9 2.6 2.8 Expected return on plan assets (7.2 ) (7.0 ) (21.4 ) (21.2 ) (0.2 ) (0.2 ) (0.6 ) (0.6 ) Amortization of prior service cost (credit) 0.1 — 0.1 0.1 (0.1 ) (0.3 ) (0.2 ) (0.7 ) Amortization of actuarial loss 4.6 4.4 13.9 13.2 0.4 0.5 1.2 1.4 $4.2 $4.2 $12.6 $12.5 $1.5 $1.4 $4.4 $4.4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. NOTE 9(b) Equity-based Compensation Plans - A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and nine months ended September 30 was as follows (in millions): Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 Compensation expense $5.1 $4.4 $9.9 $16.8 $2.8 $2.4 $5.4 $8.9 $2.1 $1.9 $4.1 $7.3 Income tax benefits 2.1 1.7 4.0 6.8 1.1 1.0 2.2 3.7 0.9 0.7 1.7 2.9 As of September 30, 2017 , Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $8.5 million , $4.7 million and $3.5 million , respectively, which is expected to be recognized over a weighted average period of between one and two years. Performance Shares and Performance Units - A summary of the performance shares and performance units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of awards, was as follows: Performance Shares Performance Units Nonvested awards, January 1 257,599 93,320 Granted 65,350 21,558 Vested (99,438 ) (37,395 ) Forfeited — (4,243 ) Nonvested awards, September 30 223,511 73,240 Vested Awards - During the nine months ended September 30 , 2017 , certain performance shares and performance units that were granted in 2014 vested, resulting in payouts (a combination of cash and common stock for the performance shares and cash only for the performance units) as follows: Performance Shares Performance Units Performance awards vested 99,438 37,395 Percentage of target number of performance awards 147.5 % 147.5 % Aggregate payout value (in millions) $5.6 $1.5 Payout - cash (in millions) $5.1 $1.5 Payout - common stock shares issued 5,185 N/A Fair Value of Awards - Information related to fair values of nonvested performance shares and performance units at September 30, 2017 , by year of grant, was as follows: Performance Shares Performance Units 2017 Grant 2016 Grant 2015 Grant 2017 Grant 2016 Grant 2015 Grant Nonvested awards at target 65,350 67,355 90,806 19,531 21,751 31,958 Alliant Energy common stock closing price on September 29, 2017 $41.57 $41.57 $41.57 $41.57 $41.57 N/A Alliant Energy common stock closing price on grant date N/A N/A N/A N/A N/A $32.55 Estimated payout percentage based on performance criteria 100 % 138 % 113 % 100 % 138 % 113 % Fair values of each nonvested award $41.57 $57.37 $46.97 $41.57 $57.37 $36.78 Performance Restricted Stock Units - A summary of the performance restricted stock units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of units, was as follows: Units Weighted Average Grant Date Fair Value Nonvested units, January 1 67,355 $33.96 Granted 65,350 39.12 Nonvested units, September 30 132,705 36.50 Restricted Stock Units - A summary of the restricted stock units activity for the nine months ended September 30 , 2017 , was as follows: Nonvested units, January 1 57,736 Granted 56,013 Nonvested units, September 30 113,749 |
IPL [Member] | |
Benefit Plans | BENEFIT PLANS NOTE 9(a) Pension and Other Postretirement Benefits Plans - Net Periodic Benefit Costs - The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and nine months ended September 30 are included in the tables below (in millions). In IPL’s and WPL’s tables below, the defined benefit pension plan amounts represent those respective amounts for their bargaining unit employees covered under the qualified plans that they sponsor, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans. In IPL’s and WPL’s tables below, the OPEB plans amounts represent respective amounts for their employees, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Corporate Services sponsored OPEB plan. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $3.1 $3.2 $9.3 $9.5 $1.2 $1.4 $3.7 $4.0 Interest cost 12.7 13.2 38.3 39.7 2.2 2.3 6.5 7.0 Expected return on plan assets (16.3 ) (16.3 ) (49.1 ) (49.1 ) (1.5 ) (1.6 ) (4.6 ) (4.6 ) Amortization of prior service credit (0.1 ) (0.1 ) (0.3 ) (0.2 ) (0.1 ) (1.0 ) (0.2 ) (3.1 ) Amortization of actuarial loss 9.4 9.3 28.2 28.0 1.0 1.2 2.9 3.6 Settlement losses (a) 0.9 — 0.9 — — — — — $9.7 $9.3 $27.3 $27.9 $2.8 $2.3 $8.3 $6.9 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.8 $1.8 $5.5 $5.6 $0.5 $0.5 $1.6 $1.7 Interest cost 5.9 6.1 17.6 18.4 0.8 1.0 2.6 2.9 Expected return on plan assets (7.7 ) (7.7 ) (23.1 ) (23.2 ) (1.0 ) (1.0 ) (3.2 ) (3.2 ) Amortization of prior service credit — — (0.1 ) (0.1 ) — (0.7 ) — (2.0 ) Amortization of actuarial loss 4.0 4.2 12.1 12.4 0.5 0.7 1.5 2.0 $4.0 $4.4 $12.0 $13.1 $0.8 $0.5 $2.5 $1.4 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.2 $1.3 $3.6 $3.7 $0.5 $0.5 $1.4 $1.5 Interest cost 5.5 5.5 16.4 16.7 0.9 0.9 2.6 2.8 Expected return on plan assets (7.2 ) (7.0 ) (21.4 ) (21.2 ) (0.2 ) (0.2 ) (0.6 ) (0.6 ) Amortization of prior service cost (credit) 0.1 — 0.1 0.1 (0.1 ) (0.3 ) (0.2 ) (0.7 ) Amortization of actuarial loss 4.6 4.4 13.9 13.2 0.4 0.5 1.2 1.4 $4.2 $4.2 $12.6 $12.5 $1.5 $1.4 $4.4 $4.4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. NOTE 9(b) Equity-based Compensation Plans - A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and nine months ended September 30 was as follows (in millions): Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 Compensation expense $5.1 $4.4 $9.9 $16.8 $2.8 $2.4 $5.4 $8.9 $2.1 $1.9 $4.1 $7.3 Income tax benefits 2.1 1.7 4.0 6.8 1.1 1.0 2.2 3.7 0.9 0.7 1.7 2.9 As of September 30, 2017 , Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $8.5 million , $4.7 million and $3.5 million , respectively, which is expected to be recognized over a weighted average period of between one and two years. Performance Shares and Performance Units - A summary of the performance shares and performance units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of awards, was as follows: Performance Shares Performance Units Nonvested awards, January 1 257,599 93,320 Granted 65,350 21,558 Vested (99,438 ) (37,395 ) Forfeited — (4,243 ) Nonvested awards, September 30 223,511 73,240 Vested Awards - During the nine months ended September 30 , 2017 , certain performance shares and performance units that were granted in 2014 vested, resulting in payouts (a combination of cash and common stock for the performance shares and cash only for the performance units) as follows: Performance Shares Performance Units Performance awards vested 99,438 37,395 Percentage of target number of performance awards 147.5 % 147.5 % Aggregate payout value (in millions) $5.6 $1.5 Payout - cash (in millions) $5.1 $1.5 Payout - common stock shares issued 5,185 N/A Fair Value of Awards - Information related to fair values of nonvested performance shares and performance units at September 30, 2017 , by year of grant, was as follows: Performance Shares Performance Units 2017 Grant 2016 Grant 2015 Grant 2017 Grant 2016 Grant 2015 Grant Nonvested awards at target 65,350 67,355 90,806 19,531 21,751 31,958 Alliant Energy common stock closing price on September 29, 2017 $41.57 $41.57 $41.57 $41.57 $41.57 N/A Alliant Energy common stock closing price on grant date N/A N/A N/A N/A N/A $32.55 Estimated payout percentage based on performance criteria 100 % 138 % 113 % 100 % 138 % 113 % Fair values of each nonvested award $41.57 $57.37 $46.97 $41.57 $57.37 $36.78 Performance Restricted Stock Units - A summary of the performance restricted stock units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of units, was as follows: Units Weighted Average Grant Date Fair Value Nonvested units, January 1 67,355 $33.96 Granted 65,350 39.12 Nonvested units, September 30 132,705 36.50 Restricted Stock Units - A summary of the restricted stock units activity for the nine months ended September 30 , 2017 , was as follows: Nonvested units, January 1 57,736 Granted 56,013 Nonvested units, September 30 113,749 |
WPL [Member] | |
Benefit Plans | BENEFIT PLANS NOTE 9(a) Pension and Other Postretirement Benefits Plans - Net Periodic Benefit Costs - The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and nine months ended September 30 are included in the tables below (in millions). In IPL’s and WPL’s tables below, the defined benefit pension plan amounts represent those respective amounts for their bargaining unit employees covered under the qualified plans that they sponsor, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans. In IPL’s and WPL’s tables below, the OPEB plans amounts represent respective amounts for their employees, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Corporate Services sponsored OPEB plan. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $3.1 $3.2 $9.3 $9.5 $1.2 $1.4 $3.7 $4.0 Interest cost 12.7 13.2 38.3 39.7 2.2 2.3 6.5 7.0 Expected return on plan assets (16.3 ) (16.3 ) (49.1 ) (49.1 ) (1.5 ) (1.6 ) (4.6 ) (4.6 ) Amortization of prior service credit (0.1 ) (0.1 ) (0.3 ) (0.2 ) (0.1 ) (1.0 ) (0.2 ) (3.1 ) Amortization of actuarial loss 9.4 9.3 28.2 28.0 1.0 1.2 2.9 3.6 Settlement losses (a) 0.9 — 0.9 — — — — — $9.7 $9.3 $27.3 $27.9 $2.8 $2.3 $8.3 $6.9 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.8 $1.8 $5.5 $5.6 $0.5 $0.5 $1.6 $1.7 Interest cost 5.9 6.1 17.6 18.4 0.8 1.0 2.6 2.9 Expected return on plan assets (7.7 ) (7.7 ) (23.1 ) (23.2 ) (1.0 ) (1.0 ) (3.2 ) (3.2 ) Amortization of prior service credit — — (0.1 ) (0.1 ) — (0.7 ) — (2.0 ) Amortization of actuarial loss 4.0 4.2 12.1 12.4 0.5 0.7 1.5 2.0 $4.0 $4.4 $12.0 $13.1 $0.8 $0.5 $2.5 $1.4 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.2 $1.3 $3.6 $3.7 $0.5 $0.5 $1.4 $1.5 Interest cost 5.5 5.5 16.4 16.7 0.9 0.9 2.6 2.8 Expected return on plan assets (7.2 ) (7.0 ) (21.4 ) (21.2 ) (0.2 ) (0.2 ) (0.6 ) (0.6 ) Amortization of prior service cost (credit) 0.1 — 0.1 0.1 (0.1 ) (0.3 ) (0.2 ) (0.7 ) Amortization of actuarial loss 4.6 4.4 13.9 13.2 0.4 0.5 1.2 1.4 $4.2 $4.2 $12.6 $12.5 $1.5 $1.4 $4.4 $4.4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. NOTE 9(b) Equity-based Compensation Plans - A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and nine months ended September 30 was as follows (in millions): Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 Compensation expense $5.1 $4.4 $9.9 $16.8 $2.8 $2.4 $5.4 $8.9 $2.1 $1.9 $4.1 $7.3 Income tax benefits 2.1 1.7 4.0 6.8 1.1 1.0 2.2 3.7 0.9 0.7 1.7 2.9 As of September 30, 2017 , Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $8.5 million , $4.7 million and $3.5 million , respectively, which is expected to be recognized over a weighted average period of between one and two years. Performance Shares and Performance Units - A summary of the performance shares and performance units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of awards, was as follows: Performance Shares Performance Units Nonvested awards, January 1 257,599 93,320 Granted 65,350 21,558 Vested (99,438 ) (37,395 ) Forfeited — (4,243 ) Nonvested awards, September 30 223,511 73,240 Vested Awards - During the nine months ended September 30 , 2017 , certain performance shares and performance units that were granted in 2014 vested, resulting in payouts (a combination of cash and common stock for the performance shares and cash only for the performance units) as follows: Performance Shares Performance Units Performance awards vested 99,438 37,395 Percentage of target number of performance awards 147.5 % 147.5 % Aggregate payout value (in millions) $5.6 $1.5 Payout - cash (in millions) $5.1 $1.5 Payout - common stock shares issued 5,185 N/A Fair Value of Awards - Information related to fair values of nonvested performance shares and performance units at September 30, 2017 , by year of grant, was as follows: Performance Shares Performance Units 2017 Grant 2016 Grant 2015 Grant 2017 Grant 2016 Grant 2015 Grant Nonvested awards at target 65,350 67,355 90,806 19,531 21,751 31,958 Alliant Energy common stock closing price on September 29, 2017 $41.57 $41.57 $41.57 $41.57 $41.57 N/A Alliant Energy common stock closing price on grant date N/A N/A N/A N/A N/A $32.55 Estimated payout percentage based on performance criteria 100 % 138 % 113 % 100 % 138 % 113 % Fair values of each nonvested award $41.57 $57.37 $46.97 $41.57 $57.37 $36.78 Performance Restricted Stock Units - A summary of the performance restricted stock units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of units, was as follows: Units Weighted Average Grant Date Fair Value Nonvested units, January 1 67,355 $33.96 Granted 65,350 39.12 Nonvested units, September 30 132,705 36.50 Restricted Stock Units - A summary of the restricted stock units activity for the nine months ended September 30 , 2017 , was as follows: Nonvested units, January 1 57,736 Granted 56,013 Nonvested units, September 30 113,749 |
Fair Value Measurements
Fair Value Measurements | 9 Months Ended |
Sep. 30, 2017 | |
Fair Value Measurements | FAIR VALUE MEASUREMENTS Valuation Hierarchy - At each reporting date, Level 1 items included IPL’s 5.1% cumulative preferred stock, Level 2 items included certain non-exchange traded commodity contracts and substantially all of the long-term debt instruments, and Level 3 items included FTRs, certain non-exchange traded commodity contracts and IPL’s deferred proceeds. Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions): Alliant Energy September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $29.4 $— $2.9 $26.5 $29.4 $41.4 $— $4.6 $36.8 $41.4 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 45.1 — 14.9 30.2 45.1 28.6 — 0.5 28.1 28.6 Long-term debt (incl. current maturities) 4,360.3 — 4,893.3 2.9 4,896.2 4,320.2 — 4,795.7 3.3 4,799.0 Cumulative preferred stock of IPL 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 IPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $21.1 $— $1.6 $19.5 $21.1 $20.8 $— $2.8 $18.0 $20.8 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 18.7 — 4.5 14.2 18.7 8.3 — 0.4 7.9 8.3 Long-term debt (incl. current maturities) 2,195.0 — 2,430.1 — 2,430.1 2,153.5 — 2,352.3 — 2,352.3 Cumulative preferred stock 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 WPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $8.3 $— $1.3 $7.0 $8.3 $20.6 $— $1.8 $18.8 $20.6 Liabilities: Derivatives 26.4 — 10.4 16.0 26.4 20.3 — 0.1 20.2 20.3 Long-term debt 1,536.2 — 1,829.3 — 1,829.3 1,535.2 — 1,807.4 — 1,807.4 Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions): Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $9.2 $0.6 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.3 ) (5.1 ) — — Transfers out of Level 3 — 0.8 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (8.5 ) (4.0 ) (54.7 ) 165.3 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.2 ) ($5.0 ) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $8.7 ($32.7 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (31.3 ) 8.0 — — Transfers into Level 3 — 0.9 — — Transfers out of Level 3 12.2 1.2 — — Purchases 28.3 22.0 — — Sales (0.3 ) (0.9 ) — — Settlements (a) (21.3 ) (6.4 ) (95.8 ) 67.7 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($29.4 ) $9.7 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $17.1 $18.3 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.4 ) (0.4 ) — — Transfers out of Level 3 — 0.3 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (7.3 ) (4.6 ) (54.7 ) 165.3 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.5 ) ($0.4 ) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $10.1 ($1.9 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (13.9 ) 4.8 — — Transfers into Level 3 — 0.5 — — Transfers out of Level 3 3.1 0.2 — — Purchases 24.6 20.6 — — Sales (0.2 ) (0.9 ) — — Settlements (a) (18.4 ) (9.9 ) (95.8 ) 67.7 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($12.6 ) $5.7 $— $— WPL Commodity Contract Derivative Assets and (Liabilities), net Three Months Ended September 30 2017 2016 Beginning balance, July 1 ($7.9 ) ($17.7 ) Total net gains (losses) included in changes in net assets (realized/unrealized) 0.1 (4.7 ) Transfers out of Level 3 — 0.5 Settlements (1.2 ) 0.6 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 $0.3 ($4.6 ) WPL Commodity Contract Derivative Assets and (Liabilities), net Nine Months Ended September 30 2017 2016 Beginning balance, January 1 ($1.4 ) ($30.8 ) Total net gains (losses) included in changes in net assets (realized/unrealized) (17.4 ) 3.2 Transfers into Level 3 — 0.4 Transfers out of Level 3 9.1 1.0 Purchases 3.7 1.4 Sales (0.1 ) — Settlements (2.9 ) 3.5 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($16.8 ) $4.0 (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold. Commodity Contracts - The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2017 ($22.2 ) $18.5 ($10.4 ) $15.7 ($11.8 ) $2.8 December 31, 2016 (2.3 ) 11.0 0.1 10.0 (2.4 ) 1.0 |
IPL [Member] | |
Fair Value Measurements | FAIR VALUE MEASUREMENTS Valuation Hierarchy - At each reporting date, Level 1 items included IPL’s 5.1% cumulative preferred stock, Level 2 items included certain non-exchange traded commodity contracts and substantially all of the long-term debt instruments, and Level 3 items included FTRs, certain non-exchange traded commodity contracts and IPL’s deferred proceeds. Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions): Alliant Energy September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $29.4 $— $2.9 $26.5 $29.4 $41.4 $— $4.6 $36.8 $41.4 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 45.1 — 14.9 30.2 45.1 28.6 — 0.5 28.1 28.6 Long-term debt (incl. current maturities) 4,360.3 — 4,893.3 2.9 4,896.2 4,320.2 — 4,795.7 3.3 4,799.0 Cumulative preferred stock of IPL 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 IPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $21.1 $— $1.6 $19.5 $21.1 $20.8 $— $2.8 $18.0 $20.8 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 18.7 — 4.5 14.2 18.7 8.3 — 0.4 7.9 8.3 Long-term debt (incl. current maturities) 2,195.0 — 2,430.1 — 2,430.1 2,153.5 — 2,352.3 — 2,352.3 Cumulative preferred stock 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 WPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $8.3 $— $1.3 $7.0 $8.3 $20.6 $— $1.8 $18.8 $20.6 Liabilities: Derivatives 26.4 — 10.4 16.0 26.4 20.3 — 0.1 20.2 20.3 Long-term debt 1,536.2 — 1,829.3 — 1,829.3 1,535.2 — 1,807.4 — 1,807.4 Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions): Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $9.2 $0.6 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.3 ) (5.1 ) — — Transfers out of Level 3 — 0.8 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (8.5 ) (4.0 ) (54.7 ) 165.3 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.2 ) ($5.0 ) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $8.7 ($32.7 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (31.3 ) 8.0 — — Transfers into Level 3 — 0.9 — — Transfers out of Level 3 12.2 1.2 — — Purchases 28.3 22.0 — — Sales (0.3 ) (0.9 ) — — Settlements (a) (21.3 ) (6.4 ) (95.8 ) 67.7 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($29.4 ) $9.7 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $17.1 $18.3 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.4 ) (0.4 ) — — Transfers out of Level 3 — 0.3 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (7.3 ) (4.6 ) (54.7 ) 165.3 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.5 ) ($0.4 ) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $10.1 ($1.9 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (13.9 ) 4.8 — — Transfers into Level 3 — 0.5 — — Transfers out of Level 3 3.1 0.2 — — Purchases 24.6 20.6 — — Sales (0.2 ) (0.9 ) — — Settlements (a) (18.4 ) (9.9 ) (95.8 ) 67.7 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($12.6 ) $5.7 $— $— WPL Commodity Contract Derivative Assets and (Liabilities), net Three Months Ended September 30 2017 2016 Beginning balance, July 1 ($7.9 ) ($17.7 ) Total net gains (losses) included in changes in net assets (realized/unrealized) 0.1 (4.7 ) Transfers out of Level 3 — 0.5 Settlements (1.2 ) 0.6 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 $0.3 ($4.6 ) WPL Commodity Contract Derivative Assets and (Liabilities), net Nine Months Ended September 30 2017 2016 Beginning balance, January 1 ($1.4 ) ($30.8 ) Total net gains (losses) included in changes in net assets (realized/unrealized) (17.4 ) 3.2 Transfers into Level 3 — 0.4 Transfers out of Level 3 9.1 1.0 Purchases 3.7 1.4 Sales (0.1 ) — Settlements (2.9 ) 3.5 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($16.8 ) $4.0 (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold. Commodity Contracts - The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2017 ($22.2 ) $18.5 ($10.4 ) $15.7 ($11.8 ) $2.8 December 31, 2016 (2.3 ) 11.0 0.1 10.0 (2.4 ) 1.0 |
WPL [Member] | |
Fair Value Measurements | FAIR VALUE MEASUREMENTS Valuation Hierarchy - At each reporting date, Level 1 items included IPL’s 5.1% cumulative preferred stock, Level 2 items included certain non-exchange traded commodity contracts and substantially all of the long-term debt instruments, and Level 3 items included FTRs, certain non-exchange traded commodity contracts and IPL’s deferred proceeds. Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions): Alliant Energy September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $29.4 $— $2.9 $26.5 $29.4 $41.4 $— $4.6 $36.8 $41.4 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 45.1 — 14.9 30.2 45.1 28.6 — 0.5 28.1 28.6 Long-term debt (incl. current maturities) 4,360.3 — 4,893.3 2.9 4,896.2 4,320.2 — 4,795.7 3.3 4,799.0 Cumulative preferred stock of IPL 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 IPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $21.1 $— $1.6 $19.5 $21.1 $20.8 $— $2.8 $18.0 $20.8 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 18.7 — 4.5 14.2 18.7 8.3 — 0.4 7.9 8.3 Long-term debt (incl. current maturities) 2,195.0 — 2,430.1 — 2,430.1 2,153.5 — 2,352.3 — 2,352.3 Cumulative preferred stock 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 WPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $8.3 $— $1.3 $7.0 $8.3 $20.6 $— $1.8 $18.8 $20.6 Liabilities: Derivatives 26.4 — 10.4 16.0 26.4 20.3 — 0.1 20.2 20.3 Long-term debt 1,536.2 — 1,829.3 — 1,829.3 1,535.2 — 1,807.4 — 1,807.4 Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions): Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $9.2 $0.6 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.3 ) (5.1 ) — — Transfers out of Level 3 — 0.8 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (8.5 ) (4.0 ) (54.7 ) 165.3 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.2 ) ($5.0 ) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $8.7 ($32.7 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (31.3 ) 8.0 — — Transfers into Level 3 — 0.9 — — Transfers out of Level 3 12.2 1.2 — — Purchases 28.3 22.0 — — Sales (0.3 ) (0.9 ) — — Settlements (a) (21.3 ) (6.4 ) (95.8 ) 67.7 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($29.4 ) $9.7 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $17.1 $18.3 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.4 ) (0.4 ) — — Transfers out of Level 3 — 0.3 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (7.3 ) (4.6 ) (54.7 ) 165.3 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.5 ) ($0.4 ) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $10.1 ($1.9 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (13.9 ) 4.8 — — Transfers into Level 3 — 0.5 — — Transfers out of Level 3 3.1 0.2 — — Purchases 24.6 20.6 — — Sales (0.2 ) (0.9 ) — — Settlements (a) (18.4 ) (9.9 ) (95.8 ) 67.7 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($12.6 ) $5.7 $— $— WPL Commodity Contract Derivative Assets and (Liabilities), net Three Months Ended September 30 2017 2016 Beginning balance, July 1 ($7.9 ) ($17.7 ) Total net gains (losses) included in changes in net assets (realized/unrealized) 0.1 (4.7 ) Transfers out of Level 3 — 0.5 Settlements (1.2 ) 0.6 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 $0.3 ($4.6 ) WPL Commodity Contract Derivative Assets and (Liabilities), net Nine Months Ended September 30 2017 2016 Beginning balance, January 1 ($1.4 ) ($30.8 ) Total net gains (losses) included in changes in net assets (realized/unrealized) (17.4 ) 3.2 Transfers into Level 3 — 0.4 Transfers out of Level 3 9.1 1.0 Purchases 3.7 1.4 Sales (0.1 ) — Settlements (2.9 ) 3.5 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($16.8 ) $4.0 (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold. Commodity Contracts - The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2017 ($22.2 ) $18.5 ($10.4 ) $15.7 ($11.8 ) $2.8 December 31, 2016 (2.3 ) 11.0 0.1 10.0 (2.4 ) 1.0 |
Derivative Instruments
Derivative Instruments | 9 Months Ended |
Sep. 30, 2017 | |
Derivative Instruments [Line Items] | |
Derivative Instruments | DERIVATIVE INSTRUMENTS Commodity Derivatives - Notional Amounts - As of September 30, 2017 , gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts, FTRs, coal contracts and diesel fuel contracts that were accounted for as commodity derivative instruments were as follows (units in thousands): Electricity FTRs Natural Gas Coal Diesel Fuel MWhs Years MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 1,645 2017-2018 14,745 2017-2018 173,234 2017-2026 4,963 2017-2019 7,308 2017-2019 IPL — — 9,219 2017-2018 79,561 2017-2026 1,820 2017-2019 — — WPL 1,645 2017-2018 5,526 2017-2018 93,673 2017-2026 3,143 2017-2018 7,308 2017-2019 Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities. The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $26.7 $29.4 $20.3 $19.1 $6.4 $10.3 Non-current derivative assets 2.7 12.0 0.8 1.7 1.9 10.3 Current derivative liabilities 18.5 13.3 4.6 2.7 13.9 10.6 Non-current derivative liabilities 26.6 15.3 14.1 5.6 12.5 9.7 Credit Risk-related Contingent Features - Various agreements contain credit risk-related contingent features, including requirements to maintain certain credit ratings and/or limitations on liability positions under the agreements based on credit ratings. Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. In the event of a material change in creditworthiness or if liability positions exceed certain contractual limits, credit support may need to be provided in the form of letters of credit or cash collateral up to the amount of exposure under the contracts, or the contracts may need to be unwound and underlying liability positions paid. At September 30, 2017 and December 31, 2016 , the aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position was not materially different than amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered. Balance Sheet Offsetting - The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, amounts would not be materially different from gross amounts of derivative assets and derivative liabilities at September 30, 2017 and December 31, 2016 . Fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) are not offset against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. |
IPL [Member] | |
Derivative Instruments [Line Items] | |
Derivative Instruments | DERIVATIVE INSTRUMENTS Commodity Derivatives - Notional Amounts - As of September 30, 2017 , gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts, FTRs, coal contracts and diesel fuel contracts that were accounted for as commodity derivative instruments were as follows (units in thousands): Electricity FTRs Natural Gas Coal Diesel Fuel MWhs Years MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 1,645 2017-2018 14,745 2017-2018 173,234 2017-2026 4,963 2017-2019 7,308 2017-2019 IPL — — 9,219 2017-2018 79,561 2017-2026 1,820 2017-2019 — — WPL 1,645 2017-2018 5,526 2017-2018 93,673 2017-2026 3,143 2017-2018 7,308 2017-2019 Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities. The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $26.7 $29.4 $20.3 $19.1 $6.4 $10.3 Non-current derivative assets 2.7 12.0 0.8 1.7 1.9 10.3 Current derivative liabilities 18.5 13.3 4.6 2.7 13.9 10.6 Non-current derivative liabilities 26.6 15.3 14.1 5.6 12.5 9.7 Credit Risk-related Contingent Features - Various agreements contain credit risk-related contingent features, including requirements to maintain certain credit ratings and/or limitations on liability positions under the agreements based on credit ratings. Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. In the event of a material change in creditworthiness or if liability positions exceed certain contractual limits, credit support may need to be provided in the form of letters of credit or cash collateral up to the amount of exposure under the contracts, or the contracts may need to be unwound and underlying liability positions paid. At September 30, 2017 and December 31, 2016 , the aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position was not materially different than amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered. Balance Sheet Offsetting - The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, amounts would not be materially different from gross amounts of derivative assets and derivative liabilities at September 30, 2017 and December 31, 2016 . Fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) are not offset against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. |
WPL [Member] | |
Derivative Instruments [Line Items] | |
Derivative Instruments | DERIVATIVE INSTRUMENTS Commodity Derivatives - Notional Amounts - As of September 30, 2017 , gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts, FTRs, coal contracts and diesel fuel contracts that were accounted for as commodity derivative instruments were as follows (units in thousands): Electricity FTRs Natural Gas Coal Diesel Fuel MWhs Years MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 1,645 2017-2018 14,745 2017-2018 173,234 2017-2026 4,963 2017-2019 7,308 2017-2019 IPL — — 9,219 2017-2018 79,561 2017-2026 1,820 2017-2019 — — WPL 1,645 2017-2018 5,526 2017-2018 93,673 2017-2026 3,143 2017-2018 7,308 2017-2019 Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities. The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $26.7 $29.4 $20.3 $19.1 $6.4 $10.3 Non-current derivative assets 2.7 12.0 0.8 1.7 1.9 10.3 Current derivative liabilities 18.5 13.3 4.6 2.7 13.9 10.6 Non-current derivative liabilities 26.6 15.3 14.1 5.6 12.5 9.7 Credit Risk-related Contingent Features - Various agreements contain credit risk-related contingent features, including requirements to maintain certain credit ratings and/or limitations on liability positions under the agreements based on credit ratings. Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. In the event of a material change in creditworthiness or if liability positions exceed certain contractual limits, credit support may need to be provided in the form of letters of credit or cash collateral up to the amount of exposure under the contracts, or the contracts may need to be unwound and underlying liability positions paid. At September 30, 2017 and December 31, 2016 , the aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position was not materially different than amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered. Balance Sheet Offsetting - The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, amounts would not be materially different from gross amounts of derivative assets and derivative liabilities at September 30, 2017 and December 31, 2016 . Fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) are not offset against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. |
Commitments And Contingencies
Commitments And Contingencies | 9 Months Ended |
Sep. 30, 2017 | |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES NOTE 12(a) Capital Purchase Obligations - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects. IPL’s projects include the installation of an SCR system at Ottumwa Unit 1 to reduce NOx emissions at the EGU. WPL’s projects include West Riverside. At September 30, 2017 , Alliant Energy’s, IPL’s and WPL’s minimum future commitments related to certain contractual obligations for these projects were $105 million , $8 million and $97 million , respectively. NOTE 12(b) Other Purchase Obligations - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. In addition, there are various purchase obligations associated with other goods and services. At September 30, 2017 , minimum future commitments related to these purchase obligations were as follows (in millions): Alliant Energy IPL WPL Purchased power (a) $1,278 $1,194 $84 Natural gas 847 422 425 Coal (b) 144 66 78 Other (c) 34 25 1 $2,303 $1,707 $588 (a) Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. (b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change. (c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017 . NOTE 12(c) Legal Proceedings - Flood Damage Claims - In 2013, several plaintiffs purporting to represent a class of residential and commercial property owners filed a complaint against Cedar Rapids and Iowa City Railway Company (CRANDIC), Alliant Energy and various other defendants in the Iowa District Court for Linn County. Plaintiffs assert claims of negligence and strict liability based on their allegations that CRANDIC (along with other defendants) caused or exacerbated flooding of the Cedar River in June 2008. In February 2016, the Iowa District Court for Linn County ruled in favor of Alliant Energy and CRANDIC and dismissed all claims against them, resulting in no loss. In August 2016, the Iowa District Court for Linn County dismissed all claims against the remaining defendants. In September 2016, plaintiffs filed a notice of appeal with the Supreme Court of Iowa. Alliant Energy does not currently believe any material losses for this complaint are both probable and reasonably estimated, and therefore has not recognized any material loss contingency amounts as of September 30, 2017 . NOTE 12(d) Guarantees and Indemnifications - RMT - In 2013, Alliant Energy sold RMT. RMT provided renewable energy services, including construction and high voltage connection services for wind and solar projects. As part of the sale, Alliant Energy indemnified the buyer for any claims, including claims of warranty under the project obligations that were commenced or are based on actions that occurred prior to the sale, except for liabilities already accounted for through adjustments to the purchase price. Alliant Energy also guaranteed RMT’s performance obligations related to certain of RMT’s projects that were commenced prior to Alliant Energy’s sale of RMT. In the first quarter of 2017, all warranty periods and performance guarantees expired and all outstanding warranty claims were resolved. Whiting Petroleum - In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Whiting Petroleum is an independent oil and gas company. Alliant Energy Resources, LLC, as the successor to a predecessor entity that owned Whiting Petroleum, and a wholly-owned subsidiary of AEF, continues to guarantee the partnership obligations of an affiliate of Whiting Petroleum under general partnership agreements in the oil and gas industry, including with respect to the future abandonment of certain platforms off the coast of California and related onshore plant and equipment owned by the partnerships. The guarantees do not include a maximum limit. As of September 30, 2017 , the present value of the abandonment obligations is estimated at $33 million . Alliant Energy is not aware of any material liabilities related to these guarantees of which it is probable that Alliant Energy Resources, LLC will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2017 . Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-regulated wind farm located in Oklahoma. The wind farm provides electricity to a third-party under a long-term purchased power agreement. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and purchased power agreement. Alliant Energy’s obligations under the operating agreement were $98 million as of September 30, 2017 and will reduce annually until expiring in July 2047 . Alliant Energy’s obligations under the purchased power agreement are subject to a maximum limit of $17 million and expire in December 2031 , subject to potential extension. Alliant Energy is not aware of any material liabilities related to this guarantee that it is probable that it will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2017 . Refer to Note 5(a) for further discussion of the non-regulated wind investment. IPL’s Minnesota Electric Distribution Assets - IPL provided indemnifications associated with the July 2015 sale of its Minnesota electric distribution assets for losses resulting from potential breach of IPL’s representations, warranties and obligations under the sale agreement. Alliant Energy and IPL believe the likelihood of having to make any material cash payments under these indemnifications is remote. IPL has not recorded any material liabilities related to these indemnifications as of September 30, 2017 . The general terms of the indemnifications provided by IPL included a maximum limit of $17 million and expire in October 2020 . NOTE 12(e) Environmental Matters - Manufactured Gas Plant (MGP) Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. Environmental liabilities related to the MGP sites are recorded based upon periodic studies. Such amounts are based on the best current estimate of the remaining amount to be incurred for investigation, remediation and monitoring costs for those sites where the investigation process has been or is substantially completed, and the minimum of the estimated cost range for those sites where the investigation is in its earlier stages. There are inherent uncertainties associated with the estimated remaining costs for MGP projects primarily due to unknown site conditions and potential changes in regulatory agency requirements. It is possible that future cost estimates will be greater than current estimates as the investigation process proceeds and as additional facts become known. Costs of future expenditures for environmental remediation obligations are not discounted. At September 30, 2017 , estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions). At September 30, 2017 , such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $12 - $31 $10 - $27 Current and non-current environmental liabilities 16 14 WPL Consent Decree - In 2013, the U.S. District Court for the Western District of Wisconsin approved a Consent Decree that WPL, along with the other owners of Edgewater and Columbia, entered into with the EPA and the Sierra Club, thereby resolving claims against WPL. Such claims included allegations that the owners of Edgewater, Nelson Dewey and Columbia violated the Prevention of Significant Deterioration program requirements, Title V Operating Permit requirements of the Clean Air Act (CAA) and the Wisconsin State Implementation Plan designed to implement the CAA. WPL has completed various requirements under the Consent Decree. WPL’s remaining requirements include installing an SCR system at Columbia Unit 2 and fuel switching or retiring Edgewater Unit 4 by December 31, 2018. The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits for Columbia Units 1 and 2, and Edgewater Units 4 and 5. In addition, the Consent Decree includes annual plant-wide SO2 and NOx emission caps for Columbia and Edgewater. WPL is also in the process of completing approximately $7 million in environmental mitigation projects. Alliant Energy and WPL currently expect to recover material costs incurred by WPL related to compliance with the terms of the Consent Decree from WPL’s electric customers. IPL Consent Decree - In 2015, the U.S. District Court for the Northern District of Iowa approved a Consent Decree that IPL entered into with the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, thereby resolving potential CAA issues associated with emissions from IPL’s coal-fired generating facilities in Iowa. IPL has completed various requirements under the Consent Decree. IPL’s remaining requirements include installing an SCR system or equivalent NOx reduction system at Ottumwa by December 31, 2019; fuel switching or retiring Prairie Creek Unit 4 by June 1, 2018, Burlington by December 31, 2021 and Prairie Creek Units 1 and 3 by December 31, 2025. The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits with varying averaging times for Burlington, Lansing, M.L. Kapp, Ottumwa and Prairie Creek. In addition, the Consent Decree includes calendar-year SO2 and NOx emission caps for Prairie Creek, and calendar-year SO2 and NOx emission caps in aggregate for Burlington, Dubuque, Lansing, M.L. Kapp, Ottumwa, Prairie Creek and Sutherland. IPL is also in the process of completing approximately $6 million in environmental mitigation projects. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to the environmental control systems and environmental mitigation projects from IPL’s electric customers. Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however future capital investments and/or modifications to EGUs to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including carbon emissions from new (CAA Section 111(b)) and existing (CAA Section 111(d)) fossil-fueled EGUs. |
IPL [Member] | |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES NOTE 12(a) Capital Purchase Obligations - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects. IPL’s projects include the installation of an SCR system at Ottumwa Unit 1 to reduce NOx emissions at the EGU. WPL’s projects include West Riverside. At September 30, 2017 , Alliant Energy’s, IPL’s and WPL’s minimum future commitments related to certain contractual obligations for these projects were $105 million , $8 million and $97 million , respectively. NOTE 12(b) Other Purchase Obligations - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. In addition, there are various purchase obligations associated with other goods and services. At September 30, 2017 , minimum future commitments related to these purchase obligations were as follows (in millions): Alliant Energy IPL WPL Purchased power (a) $1,278 $1,194 $84 Natural gas 847 422 425 Coal (b) 144 66 78 Other (c) 34 25 1 $2,303 $1,707 $588 (a) Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. (b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change. (c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017 . NOTE 12(c) Legal Proceedings - Flood Damage Claims - In 2013, several plaintiffs purporting to represent a class of residential and commercial property owners filed a complaint against Cedar Rapids and Iowa City Railway Company (CRANDIC), Alliant Energy and various other defendants in the Iowa District Court for Linn County. Plaintiffs assert claims of negligence and strict liability based on their allegations that CRANDIC (along with other defendants) caused or exacerbated flooding of the Cedar River in June 2008. In February 2016, the Iowa District Court for Linn County ruled in favor of Alliant Energy and CRANDIC and dismissed all claims against them, resulting in no loss. In August 2016, the Iowa District Court for Linn County dismissed all claims against the remaining defendants. In September 2016, plaintiffs filed a notice of appeal with the Supreme Court of Iowa. Alliant Energy does not currently believe any material losses for this complaint are both probable and reasonably estimated, and therefore has not recognized any material loss contingency amounts as of September 30, 2017 . NOTE 12(d) Guarantees and Indemnifications - RMT - In 2013, Alliant Energy sold RMT. RMT provided renewable energy services, including construction and high voltage connection services for wind and solar projects. As part of the sale, Alliant Energy indemnified the buyer for any claims, including claims of warranty under the project obligations that were commenced or are based on actions that occurred prior to the sale, except for liabilities already accounted for through adjustments to the purchase price. Alliant Energy also guaranteed RMT’s performance obligations related to certain of RMT’s projects that were commenced prior to Alliant Energy’s sale of RMT. In the first quarter of 2017, all warranty periods and performance guarantees expired and all outstanding warranty claims were resolved. Whiting Petroleum - In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Whiting Petroleum is an independent oil and gas company. Alliant Energy Resources, LLC, as the successor to a predecessor entity that owned Whiting Petroleum, and a wholly-owned subsidiary of AEF, continues to guarantee the partnership obligations of an affiliate of Whiting Petroleum under general partnership agreements in the oil and gas industry, including with respect to the future abandonment of certain platforms off the coast of California and related onshore plant and equipment owned by the partnerships. The guarantees do not include a maximum limit. As of September 30, 2017 , the present value of the abandonment obligations is estimated at $33 million . Alliant Energy is not aware of any material liabilities related to these guarantees of which it is probable that Alliant Energy Resources, LLC will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2017 . Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-regulated wind farm located in Oklahoma. The wind farm provides electricity to a third-party under a long-term purchased power agreement. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and purchased power agreement. Alliant Energy’s obligations under the operating agreement were $98 million as of September 30, 2017 and will reduce annually until expiring in July 2047 . Alliant Energy’s obligations under the purchased power agreement are subject to a maximum limit of $17 million and expire in December 2031 , subject to potential extension. Alliant Energy is not aware of any material liabilities related to this guarantee that it is probable that it will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2017 . Refer to Note 5(a) for further discussion of the non-regulated wind investment. IPL’s Minnesota Electric Distribution Assets - IPL provided indemnifications associated with the July 2015 sale of its Minnesota electric distribution assets for losses resulting from potential breach of IPL’s representations, warranties and obligations under the sale agreement. Alliant Energy and IPL believe the likelihood of having to make any material cash payments under these indemnifications is remote. IPL has not recorded any material liabilities related to these indemnifications as of September 30, 2017 . The general terms of the indemnifications provided by IPL included a maximum limit of $17 million and expire in October 2020 . NOTE 12(e) Environmental Matters - Manufactured Gas Plant (MGP) Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. Environmental liabilities related to the MGP sites are recorded based upon periodic studies. Such amounts are based on the best current estimate of the remaining amount to be incurred for investigation, remediation and monitoring costs for those sites where the investigation process has been or is substantially completed, and the minimum of the estimated cost range for those sites where the investigation is in its earlier stages. There are inherent uncertainties associated with the estimated remaining costs for MGP projects primarily due to unknown site conditions and potential changes in regulatory agency requirements. It is possible that future cost estimates will be greater than current estimates as the investigation process proceeds and as additional facts become known. Costs of future expenditures for environmental remediation obligations are not discounted. At September 30, 2017 , estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions). At September 30, 2017 , such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $12 - $31 $10 - $27 Current and non-current environmental liabilities 16 14 WPL Consent Decree - In 2013, the U.S. District Court for the Western District of Wisconsin approved a Consent Decree that WPL, along with the other owners of Edgewater and Columbia, entered into with the EPA and the Sierra Club, thereby resolving claims against WPL. Such claims included allegations that the owners of Edgewater, Nelson Dewey and Columbia violated the Prevention of Significant Deterioration program requirements, Title V Operating Permit requirements of the Clean Air Act (CAA) and the Wisconsin State Implementation Plan designed to implement the CAA. WPL has completed various requirements under the Consent Decree. WPL’s remaining requirements include installing an SCR system at Columbia Unit 2 and fuel switching or retiring Edgewater Unit 4 by December 31, 2018. The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits for Columbia Units 1 and 2, and Edgewater Units 4 and 5. In addition, the Consent Decree includes annual plant-wide SO2 and NOx emission caps for Columbia and Edgewater. WPL is also in the process of completing approximately $7 million in environmental mitigation projects. Alliant Energy and WPL currently expect to recover material costs incurred by WPL related to compliance with the terms of the Consent Decree from WPL’s electric customers. IPL Consent Decree - In 2015, the U.S. District Court for the Northern District of Iowa approved a Consent Decree that IPL entered into with the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, thereby resolving potential CAA issues associated with emissions from IPL’s coal-fired generating facilities in Iowa. IPL has completed various requirements under the Consent Decree. IPL’s remaining requirements include installing an SCR system or equivalent NOx reduction system at Ottumwa by December 31, 2019; fuel switching or retiring Prairie Creek Unit 4 by June 1, 2018, Burlington by December 31, 2021 and Prairie Creek Units 1 and 3 by December 31, 2025. The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits with varying averaging times for Burlington, Lansing, M.L. Kapp, Ottumwa and Prairie Creek. In addition, the Consent Decree includes calendar-year SO2 and NOx emission caps for Prairie Creek, and calendar-year SO2 and NOx emission caps in aggregate for Burlington, Dubuque, Lansing, M.L. Kapp, Ottumwa, Prairie Creek and Sutherland. IPL is also in the process of completing approximately $6 million in environmental mitigation projects. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to the environmental control systems and environmental mitigation projects from IPL’s electric customers. Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however future capital investments and/or modifications to EGUs to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including carbon emissions from new (CAA Section 111(b)) and existing (CAA Section 111(d)) fossil-fueled EGUs. |
WPL [Member] | |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES NOTE 12(a) Capital Purchase Obligations - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects. IPL’s projects include the installation of an SCR system at Ottumwa Unit 1 to reduce NOx emissions at the EGU. WPL’s projects include West Riverside. At September 30, 2017 , Alliant Energy’s, IPL’s and WPL’s minimum future commitments related to certain contractual obligations for these projects were $105 million , $8 million and $97 million , respectively. NOTE 12(b) Other Purchase Obligations - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. In addition, there are various purchase obligations associated with other goods and services. At September 30, 2017 , minimum future commitments related to these purchase obligations were as follows (in millions): Alliant Energy IPL WPL Purchased power (a) $1,278 $1,194 $84 Natural gas 847 422 425 Coal (b) 144 66 78 Other (c) 34 25 1 $2,303 $1,707 $588 (a) Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. (b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change. (c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017 . NOTE 12(c) Legal Proceedings - Flood Damage Claims - In 2013, several plaintiffs purporting to represent a class of residential and commercial property owners filed a complaint against Cedar Rapids and Iowa City Railway Company (CRANDIC), Alliant Energy and various other defendants in the Iowa District Court for Linn County. Plaintiffs assert claims of negligence and strict liability based on their allegations that CRANDIC (along with other defendants) caused or exacerbated flooding of the Cedar River in June 2008. In February 2016, the Iowa District Court for Linn County ruled in favor of Alliant Energy and CRANDIC and dismissed all claims against them, resulting in no loss. In August 2016, the Iowa District Court for Linn County dismissed all claims against the remaining defendants. In September 2016, plaintiffs filed a notice of appeal with the Supreme Court of Iowa. Alliant Energy does not currently believe any material losses for this complaint are both probable and reasonably estimated, and therefore has not recognized any material loss contingency amounts as of September 30, 2017 . NOTE 12(d) Guarantees and Indemnifications - RMT - In 2013, Alliant Energy sold RMT. RMT provided renewable energy services, including construction and high voltage connection services for wind and solar projects. As part of the sale, Alliant Energy indemnified the buyer for any claims, including claims of warranty under the project obligations that were commenced or are based on actions that occurred prior to the sale, except for liabilities already accounted for through adjustments to the purchase price. Alliant Energy also guaranteed RMT’s performance obligations related to certain of RMT’s projects that were commenced prior to Alliant Energy’s sale of RMT. In the first quarter of 2017, all warranty periods and performance guarantees expired and all outstanding warranty claims were resolved. Whiting Petroleum - In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Whiting Petroleum is an independent oil and gas company. Alliant Energy Resources, LLC, as the successor to a predecessor entity that owned Whiting Petroleum, and a wholly-owned subsidiary of AEF, continues to guarantee the partnership obligations of an affiliate of Whiting Petroleum under general partnership agreements in the oil and gas industry, including with respect to the future abandonment of certain platforms off the coast of California and related onshore plant and equipment owned by the partnerships. The guarantees do not include a maximum limit. As of September 30, 2017 , the present value of the abandonment obligations is estimated at $33 million . Alliant Energy is not aware of any material liabilities related to these guarantees of which it is probable that Alliant Energy Resources, LLC will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2017 . Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-regulated wind farm located in Oklahoma. The wind farm provides electricity to a third-party under a long-term purchased power agreement. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and purchased power agreement. Alliant Energy’s obligations under the operating agreement were $98 million as of September 30, 2017 and will reduce annually until expiring in July 2047 . Alliant Energy’s obligations under the purchased power agreement are subject to a maximum limit of $17 million and expire in December 2031 , subject to potential extension. Alliant Energy is not aware of any material liabilities related to this guarantee that it is probable that it will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2017 . Refer to Note 5(a) for further discussion of the non-regulated wind investment. IPL’s Minnesota Electric Distribution Assets - IPL provided indemnifications associated with the July 2015 sale of its Minnesota electric distribution assets for losses resulting from potential breach of IPL’s representations, warranties and obligations under the sale agreement. Alliant Energy and IPL believe the likelihood of having to make any material cash payments under these indemnifications is remote. IPL has not recorded any material liabilities related to these indemnifications as of September 30, 2017 . The general terms of the indemnifications provided by IPL included a maximum limit of $17 million and expire in October 2020 . NOTE 12(e) Environmental Matters - Manufactured Gas Plant (MGP) Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. Environmental liabilities related to the MGP sites are recorded based upon periodic studies. Such amounts are based on the best current estimate of the remaining amount to be incurred for investigation, remediation and monitoring costs for those sites where the investigation process has been or is substantially completed, and the minimum of the estimated cost range for those sites where the investigation is in its earlier stages. There are inherent uncertainties associated with the estimated remaining costs for MGP projects primarily due to unknown site conditions and potential changes in regulatory agency requirements. It is possible that future cost estimates will be greater than current estimates as the investigation process proceeds and as additional facts become known. Costs of future expenditures for environmental remediation obligations are not discounted. At September 30, 2017 , estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions). At September 30, 2017 , such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $12 - $31 $10 - $27 Current and non-current environmental liabilities 16 14 WPL Consent Decree - In 2013, the U.S. District Court for the Western District of Wisconsin approved a Consent Decree that WPL, along with the other owners of Edgewater and Columbia, entered into with the EPA and the Sierra Club, thereby resolving claims against WPL. Such claims included allegations that the owners of Edgewater, Nelson Dewey and Columbia violated the Prevention of Significant Deterioration program requirements, Title V Operating Permit requirements of the Clean Air Act (CAA) and the Wisconsin State Implementation Plan designed to implement the CAA. WPL has completed various requirements under the Consent Decree. WPL’s remaining requirements include installing an SCR system at Columbia Unit 2 and fuel switching or retiring Edgewater Unit 4 by December 31, 2018. The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits for Columbia Units 1 and 2, and Edgewater Units 4 and 5. In addition, the Consent Decree includes annual plant-wide SO2 and NOx emission caps for Columbia and Edgewater. WPL is also in the process of completing approximately $7 million in environmental mitigation projects. Alliant Energy and WPL currently expect to recover material costs incurred by WPL related to compliance with the terms of the Consent Decree from WPL’s electric customers. IPL Consent Decree - In 2015, the U.S. District Court for the Northern District of Iowa approved a Consent Decree that IPL entered into with the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, thereby resolving potential CAA issues associated with emissions from IPL’s coal-fired generating facilities in Iowa. IPL has completed various requirements under the Consent Decree. IPL’s remaining requirements include installing an SCR system or equivalent NOx reduction system at Ottumwa by December 31, 2019; fuel switching or retiring Prairie Creek Unit 4 by June 1, 2018, Burlington by December 31, 2021 and Prairie Creek Units 1 and 3 by December 31, 2025. The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits with varying averaging times for Burlington, Lansing, M.L. Kapp, Ottumwa and Prairie Creek. In addition, the Consent Decree includes calendar-year SO2 and NOx emission caps for Prairie Creek, and calendar-year SO2 and NOx emission caps in aggregate for Burlington, Dubuque, Lansing, M.L. Kapp, Ottumwa, Prairie Creek and Sutherland. IPL is also in the process of completing approximately $6 million in environmental mitigation projects. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to the environmental control systems and environmental mitigation projects from IPL’s electric customers. Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however future capital investments and/or modifications to EGUs to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including carbon emissions from new (CAA Section 111(b)) and existing (CAA Section 111(d)) fossil-fueled EGUs. |
Segments Of Business
Segments Of Business | 9 Months Ended |
Sep. 30, 2017 | |
Segment Reporting Information [Line Items] | |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm. Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2017 Operating revenues $840.6 $45.8 $11.2 $897.6 $9.3 $906.9 Operating income (loss) 232.6 (2.4 ) (7.7 ) 222.5 9.0 231.5 Net income (loss) attributable to Alliant Energy common shareowners 176.3 (7.5 ) 168.8 Three Months Ended September 30, 2016 Operating revenues $864.3 $39.5 $9.4 $913.2 $11.4 $924.6 Operating income (loss) 244.2 (3.7 ) 0.4 240.9 (78.3 ) 162.6 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 183.1 (54.3 ) 128.8 Loss from discontinued operations, net of tax — (0.4 ) (0.4 ) Net income (loss) 183.1 (54.7 ) 128.4 Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2017 Operating revenues $2,199.1 $262.7 $34.4 $2,496.2 $29.9 $2,526.1 Operating income (loss) 475.4 29.5 (6.8 ) 498.1 25.6 523.7 Amounts attributable to Alliant Energy common shareowners: Income from continuing operations, net of tax 353.5 8.6 362.1 Income from discontinued operations, net of tax — 1.4 1.4 Net income 353.5 10.0 363.5 Nine Months Ended September 30, 2016 Operating revenues $2,209.1 $248.7 $35.0 $2,492.8 $30.2 $2,523.0 Operating income (loss) 473.3 27.0 4.4 504.7 (67.6 ) 437.1 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 350.3 (39.5 ) 310.8 Loss from discontinued operations, net of tax — (2.0 ) (2.0 ) Net income (loss) 350.3 (41.5 ) 308.8 (a) Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. IPL - Certain financial information relating to IPL’s business segments is as follows. Intersegment revenues were not material to IPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $489.0 $27.4 $11.0 $527.4 Operating income (loss) 138.3 (2.1 ) (4.4 ) 131.8 Earnings available for common stock 120.4 Three Months Ended September 30, 2016 Operating revenues $483.2 $23.9 $9.1 $516.2 Operating income (loss) 125.9 (1.4 ) 1.4 125.9 Earnings available for common stock 114.1 Nine Months Ended September 30, 2017 Operating revenues $1,217.6 $147.2 $33.3 $1,398.1 Operating income (loss) 234.5 14.7 (1.5 ) 247.7 Earnings available for common stock 200.4 Nine Months Ended September 30, 2016 Operating revenues $1,209.2 $142.6 $34.1 $1,385.9 Operating income 213.8 15.3 6.8 235.9 Earnings available for common stock 191.6 WPL - Certain financial information relating to WPL’s business segments is as follows. Intersegment revenues were not material to WPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $351.6 $18.4 $0.2 $370.2 Operating income (loss) 94.3 (0.3 ) (3.3 ) 90.7 Earnings available for common stock 49.8 Three Months Ended September 30, 2016 Operating revenues $381.1 $15.6 $0.3 $397.0 Operating income (loss) 118.3 (2.3 ) (1.0 ) 115.0 Earnings available for common stock 69.0 Nine Months Ended September 30, 2017 Operating revenues $981.5 $115.5 $1.1 $1,098.1 Operating income (loss) 240.9 14.8 (5.3 ) 250.4 Earnings available for common stock 133.4 Nine Months Ended September 30, 2016 Operating revenues $999.9 $106.1 $0.9 $1,106.9 Operating income (loss) 259.5 11.7 (2.4 ) 268.8 Earnings available for common stock 158.7 |
IPL [Member] | |
Segment Reporting Information [Line Items] | |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm. Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2017 Operating revenues $840.6 $45.8 $11.2 $897.6 $9.3 $906.9 Operating income (loss) 232.6 (2.4 ) (7.7 ) 222.5 9.0 231.5 Net income (loss) attributable to Alliant Energy common shareowners 176.3 (7.5 ) 168.8 Three Months Ended September 30, 2016 Operating revenues $864.3 $39.5 $9.4 $913.2 $11.4 $924.6 Operating income (loss) 244.2 (3.7 ) 0.4 240.9 (78.3 ) 162.6 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 183.1 (54.3 ) 128.8 Loss from discontinued operations, net of tax — (0.4 ) (0.4 ) Net income (loss) 183.1 (54.7 ) 128.4 Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2017 Operating revenues $2,199.1 $262.7 $34.4 $2,496.2 $29.9 $2,526.1 Operating income (loss) 475.4 29.5 (6.8 ) 498.1 25.6 523.7 Amounts attributable to Alliant Energy common shareowners: Income from continuing operations, net of tax 353.5 8.6 362.1 Income from discontinued operations, net of tax — 1.4 1.4 Net income 353.5 10.0 363.5 Nine Months Ended September 30, 2016 Operating revenues $2,209.1 $248.7 $35.0 $2,492.8 $30.2 $2,523.0 Operating income (loss) 473.3 27.0 4.4 504.7 (67.6 ) 437.1 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 350.3 (39.5 ) 310.8 Loss from discontinued operations, net of tax — (2.0 ) (2.0 ) Net income (loss) 350.3 (41.5 ) 308.8 (a) Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. IPL - Certain financial information relating to IPL’s business segments is as follows. Intersegment revenues were not material to IPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $489.0 $27.4 $11.0 $527.4 Operating income (loss) 138.3 (2.1 ) (4.4 ) 131.8 Earnings available for common stock 120.4 Three Months Ended September 30, 2016 Operating revenues $483.2 $23.9 $9.1 $516.2 Operating income (loss) 125.9 (1.4 ) 1.4 125.9 Earnings available for common stock 114.1 Nine Months Ended September 30, 2017 Operating revenues $1,217.6 $147.2 $33.3 $1,398.1 Operating income (loss) 234.5 14.7 (1.5 ) 247.7 Earnings available for common stock 200.4 Nine Months Ended September 30, 2016 Operating revenues $1,209.2 $142.6 $34.1 $1,385.9 Operating income 213.8 15.3 6.8 235.9 Earnings available for common stock 191.6 WPL - Certain financial information relating to WPL’s business segments is as follows. Intersegment revenues were not material to WPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $351.6 $18.4 $0.2 $370.2 Operating income (loss) 94.3 (0.3 ) (3.3 ) 90.7 Earnings available for common stock 49.8 Three Months Ended September 30, 2016 Operating revenues $381.1 $15.6 $0.3 $397.0 Operating income (loss) 118.3 (2.3 ) (1.0 ) 115.0 Earnings available for common stock 69.0 Nine Months Ended September 30, 2017 Operating revenues $981.5 $115.5 $1.1 $1,098.1 Operating income (loss) 240.9 14.8 (5.3 ) 250.4 Earnings available for common stock 133.4 Nine Months Ended September 30, 2016 Operating revenues $999.9 $106.1 $0.9 $1,106.9 Operating income (loss) 259.5 11.7 (2.4 ) 268.8 Earnings available for common stock 158.7 |
WPL [Member] | |
Segment Reporting Information [Line Items] | |
Segments Of Business | SEGMENTS OF BUSINESS Alliant Energy - Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm. Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2017 Operating revenues $840.6 $45.8 $11.2 $897.6 $9.3 $906.9 Operating income (loss) 232.6 (2.4 ) (7.7 ) 222.5 9.0 231.5 Net income (loss) attributable to Alliant Energy common shareowners 176.3 (7.5 ) 168.8 Three Months Ended September 30, 2016 Operating revenues $864.3 $39.5 $9.4 $913.2 $11.4 $924.6 Operating income (loss) 244.2 (3.7 ) 0.4 240.9 (78.3 ) 162.6 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 183.1 (54.3 ) 128.8 Loss from discontinued operations, net of tax — (0.4 ) (0.4 ) Net income (loss) 183.1 (54.7 ) 128.4 Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2017 Operating revenues $2,199.1 $262.7 $34.4 $2,496.2 $29.9 $2,526.1 Operating income (loss) 475.4 29.5 (6.8 ) 498.1 25.6 523.7 Amounts attributable to Alliant Energy common shareowners: Income from continuing operations, net of tax 353.5 8.6 362.1 Income from discontinued operations, net of tax — 1.4 1.4 Net income 353.5 10.0 363.5 Nine Months Ended September 30, 2016 Operating revenues $2,209.1 $248.7 $35.0 $2,492.8 $30.2 $2,523.0 Operating income (loss) 473.3 27.0 4.4 504.7 (67.6 ) 437.1 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 350.3 (39.5 ) 310.8 Loss from discontinued operations, net of tax — (2.0 ) (2.0 ) Net income (loss) 350.3 (41.5 ) 308.8 (a) Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. IPL - Certain financial information relating to IPL’s business segments is as follows. Intersegment revenues were not material to IPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $489.0 $27.4 $11.0 $527.4 Operating income (loss) 138.3 (2.1 ) (4.4 ) 131.8 Earnings available for common stock 120.4 Three Months Ended September 30, 2016 Operating revenues $483.2 $23.9 $9.1 $516.2 Operating income (loss) 125.9 (1.4 ) 1.4 125.9 Earnings available for common stock 114.1 Nine Months Ended September 30, 2017 Operating revenues $1,217.6 $147.2 $33.3 $1,398.1 Operating income (loss) 234.5 14.7 (1.5 ) 247.7 Earnings available for common stock 200.4 Nine Months Ended September 30, 2016 Operating revenues $1,209.2 $142.6 $34.1 $1,385.9 Operating income 213.8 15.3 6.8 235.9 Earnings available for common stock 191.6 WPL - Certain financial information relating to WPL’s business segments is as follows. Intersegment revenues were not material to WPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $351.6 $18.4 $0.2 $370.2 Operating income (loss) 94.3 (0.3 ) (3.3 ) 90.7 Earnings available for common stock 49.8 Three Months Ended September 30, 2016 Operating revenues $381.1 $15.6 $0.3 $397.0 Operating income (loss) 118.3 (2.3 ) (1.0 ) 115.0 Earnings available for common stock 69.0 Nine Months Ended September 30, 2017 Operating revenues $981.5 $115.5 $1.1 $1,098.1 Operating income (loss) 240.9 14.8 (5.3 ) 250.4 Earnings available for common stock 133.4 Nine Months Ended September 30, 2016 Operating revenues $999.9 $106.1 $0.9 $1,106.9 Operating income (loss) 259.5 11.7 (2.4 ) 268.8 Earnings available for common stock 158.7 |
Related Parties
Related Parties | 9 Months Ended |
Sep. 30, 2017 | |
Related Party Transactions [Line Items] | |
Related Parties | RELATED PARTIES Service Agreements - Pursuant to service agreements, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, fees associated with various professional services, depreciation and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions): IPL WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 Corporate Services billings $48 $41 $130 $124 $37 $33 $100 $103 Sales credited 8 4 15 7 6 3 8 6 Purchases billed 109 126 271 324 32 23 99 65 Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Net payables to Corporate Services $118 $104 $64 $72 ATC LLC - Pursuant to various agreements, WPL receives a range of transmission services from ATC LLC. WPL provides operation, maintenance, and construction services to ATC LLC. WPL and ATC LLC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 ATC LLC billings to WPL $26 $28 $79 $82 WPL billings to ATC LLC 2 4 8 10 WPL owed ATC LLC net amounts of $8 million as of September 30, 2017 and $8 million as of December 31, 2016 . Refer to Note 5(a) for discussion of WPL’s transfer of its investment in ATC LLC to ATI on December 31, 2016. Franklin County Wind Farm - Refer to Note 3 for discussion of the transfer of the Franklin County wind farm from AEF to IPL in April 2017. |
IPL [Member] | |
Related Party Transactions [Line Items] | |
Related Parties | RELATED PARTIES Service Agreements - Pursuant to service agreements, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, fees associated with various professional services, depreciation and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions): IPL WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 Corporate Services billings $48 $41 $130 $124 $37 $33 $100 $103 Sales credited 8 4 15 7 6 3 8 6 Purchases billed 109 126 271 324 32 23 99 65 Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Net payables to Corporate Services $118 $104 $64 $72 ATC LLC - Pursuant to various agreements, WPL receives a range of transmission services from ATC LLC. WPL provides operation, maintenance, and construction services to ATC LLC. WPL and ATC LLC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 ATC LLC billings to WPL $26 $28 $79 $82 WPL billings to ATC LLC 2 4 8 10 WPL owed ATC LLC net amounts of $8 million as of September 30, 2017 and $8 million as of December 31, 2016 . Refer to Note 5(a) for discussion of WPL’s transfer of its investment in ATC LLC to ATI on December 31, 2016. Franklin County Wind Farm - Refer to Note 3 for discussion of the transfer of the Franklin County wind farm from AEF to IPL in April 2017. |
WPL [Member] | |
Related Party Transactions [Line Items] | |
Related Parties | RELATED PARTIES Service Agreements - Pursuant to service agreements, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, fees associated with various professional services, depreciation and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions): IPL WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 Corporate Services billings $48 $41 $130 $124 $37 $33 $100 $103 Sales credited 8 4 15 7 6 3 8 6 Purchases billed 109 126 271 324 32 23 99 65 Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Net payables to Corporate Services $118 $104 $64 $72 ATC LLC - Pursuant to various agreements, WPL receives a range of transmission services from ATC LLC. WPL provides operation, maintenance, and construction services to ATC LLC. WPL and ATC LLC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 ATC LLC billings to WPL $26 $28 $79 $82 WPL billings to ATC LLC 2 4 8 10 WPL owed ATC LLC net amounts of $8 million as of September 30, 2017 and $8 million as of December 31, 2016 . Refer to Note 5(a) for discussion of WPL’s transfer of its investment in ATC LLC to ATI on December 31, 2016. |
Summary Of Significant Accoun20
Summary Of Significant Accounting Policies (Policy) | 9 Months Ended |
Sep. 30, 2017 | |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the latest combined Annual Report on Form 10-K. |
General, Use of Estimates | In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2017 are not necessarily indicative of results that may be expected for the year ending December 31, 2017 . A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. |
General, Reclassification | Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes. |
General, Discontinued Operations | Discontinued operations reported in Alliant Energy’s income statements is related to various warranty claims associated with the sale of RMT in 2013, which have resulted in operating expenses and income subsequent to the sale. |
New Accounting Standards | New Accounting Standards - Revenue Recognition - In May 2014, the Financial Accounting Standards Board issued an accounting standard providing principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This standard also requires disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018 and currently expect to use the modified retrospective method of adoption. If applicable, this method requires a cumulative-effect adjustment to the opening retained earnings balance on January 1, 2018, as if the standard had always been in effect. Alliant Energy, IPL and WPL have continued to make progress in the evaluation of the revenue recognition standard and do not currently anticipate a significant change in revenue recognition for retail electric and gas sales. These sales represent the majority of Alliant Energy’s, IPL’s and WPL’s revenues and are from tariff offerings that provide electricity or natural gas without a defined contractual term. For such arrangements, revenues from contracts with customers will be equivalent to the electricity or natural gas supplied and billed, or estimated to be billed, and there will be no significant shift in the timing or pattern of revenue recognition for such sales. The most significant impact to the financial statements for Alliant Energy, IPL and WPL is expected to be in the form of additional disclosures. The incremental disclosures could include disaggregation of revenue by location and customer class. Alliant Energy, IPL and WPL expect to complete the evaluation of the impact of the revenue recognition standard on their financial condition, results of operations and disclosures by January 1, 2018. Leases - In February 2016, the Financial Accounting Standards Board issued an accounting standard requiring lease assets and lease liabilities, including operating leases, to be recognized on the balance sheet for all leases with terms longer than 12 months. The standard also requires disclosure of key information about leasing arrangements. Alliant Energy, IPL and WPL currently expect to adopt this standard on January 1, 2019 and are evaluating the impact of this standard on their financial condition and results of operations and expect an increase in assets and liabilities from recognizing operating leases on their balance sheets. Presentation of Net Periodic Pension and Postretirement Benefit Costs - In March 2017, the Financial Accounting Standards Board issued an accounting standard amending the income statement presentation of the components of net periodic benefit costs for defined benefit pension and other postretirement plans. The standard requires entities to (1) disaggregate the current service cost component from the other components of net periodic benefit costs and present it with other employee compensation costs in the income statement; and (2) include the other components in the income statement outside of operating income. This new presentation will shift the majority of the net periodic benefit costs from “Other operation and maintenance” expenses to “Interest expense and other” expenses in the income statements. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization into property, plant and equipment, when applicable. IPL and WPL, as rate-regulated entities, currently expect to capitalize the other components of net periodic benefit costs into regulatory assets or regulatory liabilities. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018. Upon adoption, the standard must be applied retrospectively for the presentation requirements and prospectively for the capitalization requirements. Alliant Energy, IPL and WPL continue to evaluate additional impacts of this standard on their financial condition and results of operations. |
IPL [Member] | |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the latest combined Annual Report on Form 10-K. |
General, Use of Estimates | In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2017 are not necessarily indicative of results that may be expected for the year ending December 31, 2017 . A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. |
General, Reclassification | Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes. |
New Accounting Standards | New Accounting Standards - Revenue Recognition - In May 2014, the Financial Accounting Standards Board issued an accounting standard providing principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This standard also requires disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018 and currently expect to use the modified retrospective method of adoption. If applicable, this method requires a cumulative-effect adjustment to the opening retained earnings balance on January 1, 2018, as if the standard had always been in effect. Alliant Energy, IPL and WPL have continued to make progress in the evaluation of the revenue recognition standard and do not currently anticipate a significant change in revenue recognition for retail electric and gas sales. These sales represent the majority of Alliant Energy’s, IPL’s and WPL’s revenues and are from tariff offerings that provide electricity or natural gas without a defined contractual term. For such arrangements, revenues from contracts with customers will be equivalent to the electricity or natural gas supplied and billed, or estimated to be billed, and there will be no significant shift in the timing or pattern of revenue recognition for such sales. The most significant impact to the financial statements for Alliant Energy, IPL and WPL is expected to be in the form of additional disclosures. The incremental disclosures could include disaggregation of revenue by location and customer class. Alliant Energy, IPL and WPL expect to complete the evaluation of the impact of the revenue recognition standard on their financial condition, results of operations and disclosures by January 1, 2018. Leases - In February 2016, the Financial Accounting Standards Board issued an accounting standard requiring lease assets and lease liabilities, including operating leases, to be recognized on the balance sheet for all leases with terms longer than 12 months. The standard also requires disclosure of key information about leasing arrangements. Alliant Energy, IPL and WPL currently expect to adopt this standard on January 1, 2019 and are evaluating the impact of this standard on their financial condition and results of operations and expect an increase in assets and liabilities from recognizing operating leases on their balance sheets. Presentation of Net Periodic Pension and Postretirement Benefit Costs - In March 2017, the Financial Accounting Standards Board issued an accounting standard amending the income statement presentation of the components of net periodic benefit costs for defined benefit pension and other postretirement plans. The standard requires entities to (1) disaggregate the current service cost component from the other components of net periodic benefit costs and present it with other employee compensation costs in the income statement; and (2) include the other components in the income statement outside of operating income. This new presentation will shift the majority of the net periodic benefit costs from “Other operation and maintenance” expenses to “Interest expense and other” expenses in the income statements. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization into property, plant and equipment, when applicable. IPL and WPL, as rate-regulated entities, currently expect to capitalize the other components of net periodic benefit costs into regulatory assets or regulatory liabilities. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018. Upon adoption, the standard must be applied retrospectively for the presentation requirements and prospectively for the capitalization requirements. Alliant Energy, IPL and WPL continue to evaluate additional impacts of this standard on their financial condition and results of operations. |
WPL [Member] | |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the latest combined Annual Report on Form 10-K. |
General, Use of Estimates | In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2017 are not necessarily indicative of results that may be expected for the year ending December 31, 2017 . A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. |
General, Reclassification | Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes. |
New Accounting Standards | New Accounting Standards - Revenue Recognition - In May 2014, the Financial Accounting Standards Board issued an accounting standard providing principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This standard also requires disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018 and currently expect to use the modified retrospective method of adoption. If applicable, this method requires a cumulative-effect adjustment to the opening retained earnings balance on January 1, 2018, as if the standard had always been in effect. Alliant Energy, IPL and WPL have continued to make progress in the evaluation of the revenue recognition standard and do not currently anticipate a significant change in revenue recognition for retail electric and gas sales. These sales represent the majority of Alliant Energy’s, IPL’s and WPL’s revenues and are from tariff offerings that provide electricity or natural gas without a defined contractual term. For such arrangements, revenues from contracts with customers will be equivalent to the electricity or natural gas supplied and billed, or estimated to be billed, and there will be no significant shift in the timing or pattern of revenue recognition for such sales. The most significant impact to the financial statements for Alliant Energy, IPL and WPL is expected to be in the form of additional disclosures. The incremental disclosures could include disaggregation of revenue by location and customer class. Alliant Energy, IPL and WPL expect to complete the evaluation of the impact of the revenue recognition standard on their financial condition, results of operations and disclosures by January 1, 2018. Leases - In February 2016, the Financial Accounting Standards Board issued an accounting standard requiring lease assets and lease liabilities, including operating leases, to be recognized on the balance sheet for all leases with terms longer than 12 months. The standard also requires disclosure of key information about leasing arrangements. Alliant Energy, IPL and WPL currently expect to adopt this standard on January 1, 2019 and are evaluating the impact of this standard on their financial condition and results of operations and expect an increase in assets and liabilities from recognizing operating leases on their balance sheets. Presentation of Net Periodic Pension and Postretirement Benefit Costs - In March 2017, the Financial Accounting Standards Board issued an accounting standard amending the income statement presentation of the components of net periodic benefit costs for defined benefit pension and other postretirement plans. The standard requires entities to (1) disaggregate the current service cost component from the other components of net periodic benefit costs and present it with other employee compensation costs in the income statement; and (2) include the other components in the income statement outside of operating income. This new presentation will shift the majority of the net periodic benefit costs from “Other operation and maintenance” expenses to “Interest expense and other” expenses in the income statements. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization into property, plant and equipment, when applicable. IPL and WPL, as rate-regulated entities, currently expect to capitalize the other components of net periodic benefit costs into regulatory assets or regulatory liabilities. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018. Upon adoption, the standard must be applied retrospectively for the presentation requirements and prospectively for the capitalization requirements. Alliant Energy, IPL and WPL continue to evaluate additional impacts of this standard on their financial condition and results of operations. |
Regulatory Matters (Tables)
Regulatory Matters (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Regulatory Assets [Line Items] | |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Tax-related $1,147.9 $1,055.6 $1,107.9 $1,022.4 $40.0 $33.2 Pension and OPEB costs 547.8 578.7 279.3 294.0 268.5 284.7 Asset retirement obligations 107.9 105.9 71.9 64.3 36.0 41.6 EGUs retired early 67.4 41.4 32.9 — 34.5 41.4 Derivatives 49.9 30.7 22.3 10.0 27.6 20.7 Emission allowances 25.6 26.2 25.6 26.2 — — Other 90.0 76.6 51.0 41.9 39.0 34.7 $2,036.5 $1,915.1 $1,590.9 $1,458.8 $445.6 $456.3 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Cost of removal obligations $412.1 $411.6 $272.9 $269.4 $139.2 $142.2 Electric transmission cost recovery 94.8 72.0 35.9 35.7 58.9 36.3 IPL’s tax benefit riders 45.0 83.5 45.0 83.5 — — Commodity cost recovery 21.2 30.8 15.0 17.8 6.2 13.0 Energy efficiency cost recovery 20.0 20.5 — — 20.0 20.5 Derivatives 10.9 31.5 5.8 12.1 5.1 19.4 Other 24.5 31.1 10.2 12.3 14.3 18.8 $628.5 $681.0 $384.8 $430.8 $243.7 $250.2 |
Tax Benefit Riders | For the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s “IPL’s tax benefit riders” regulatory liabilities decreased by ($39) million as follows (in millions): Electric tax benefit rider credits ($51 ) Gas tax benefit rider credits (5 ) Rate-making accounting change 17 ($39 ) |
IPL [Member] | |
Regulatory Assets [Line Items] | |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Tax-related $1,147.9 $1,055.6 $1,107.9 $1,022.4 $40.0 $33.2 Pension and OPEB costs 547.8 578.7 279.3 294.0 268.5 284.7 Asset retirement obligations 107.9 105.9 71.9 64.3 36.0 41.6 EGUs retired early 67.4 41.4 32.9 — 34.5 41.4 Derivatives 49.9 30.7 22.3 10.0 27.6 20.7 Emission allowances 25.6 26.2 25.6 26.2 — — Other 90.0 76.6 51.0 41.9 39.0 34.7 $2,036.5 $1,915.1 $1,590.9 $1,458.8 $445.6 $456.3 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Cost of removal obligations $412.1 $411.6 $272.9 $269.4 $139.2 $142.2 Electric transmission cost recovery 94.8 72.0 35.9 35.7 58.9 36.3 IPL’s tax benefit riders 45.0 83.5 45.0 83.5 — — Commodity cost recovery 21.2 30.8 15.0 17.8 6.2 13.0 Energy efficiency cost recovery 20.0 20.5 — — 20.0 20.5 Derivatives 10.9 31.5 5.8 12.1 5.1 19.4 Other 24.5 31.1 10.2 12.3 14.3 18.8 $628.5 $681.0 $384.8 $430.8 $243.7 $250.2 |
Tax Benefit Riders | For the nine months ended September 30 , 2017 , Alliant Energy’s and IPL’s “IPL’s tax benefit riders” regulatory liabilities decreased by ($39) million as follows (in millions): Electric tax benefit rider credits ($51 ) Gas tax benefit rider credits (5 ) Rate-making accounting change 17 ($39 ) |
WPL [Member] | |
Regulatory Assets [Line Items] | |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Tax-related $1,147.9 $1,055.6 $1,107.9 $1,022.4 $40.0 $33.2 Pension and OPEB costs 547.8 578.7 279.3 294.0 268.5 284.7 Asset retirement obligations 107.9 105.9 71.9 64.3 36.0 41.6 EGUs retired early 67.4 41.4 32.9 — 34.5 41.4 Derivatives 49.9 30.7 22.3 10.0 27.6 20.7 Emission allowances 25.6 26.2 25.6 26.2 — — Other 90.0 76.6 51.0 41.9 39.0 34.7 $2,036.5 $1,915.1 $1,590.9 $1,458.8 $445.6 $456.3 |
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Cost of removal obligations $412.1 $411.6 $272.9 $269.4 $139.2 $142.2 Electric transmission cost recovery 94.8 72.0 35.9 35.7 58.9 36.3 IPL’s tax benefit riders 45.0 83.5 45.0 83.5 — — Commodity cost recovery 21.2 30.8 15.0 17.8 6.2 13.0 Energy efficiency cost recovery 20.0 20.5 — — 20.0 20.5 Derivatives 10.9 31.5 5.8 12.1 5.1 19.4 Other 24.5 31.1 10.2 12.3 14.3 18.8 $628.5 $681.0 $384.8 $430.8 $243.7 $250.2 |
Property, Plant and Equipment
Property, Plant and Equipment (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Property, Plant and Equipment [Line Items] | |
Property, Plant and Equipment [Table Text Block] | As of the closing date, the estimated fair values of the assets purchased and liabilities assumed by IPL were as follows (in millions): Electric plant in service $40 Current assets 2 Total assets acquired 42 Other liabilities 10 Net assets acquired $32 |
IPL [Member] | |
Property, Plant and Equipment [Line Items] | |
Property, Plant and Equipment [Table Text Block] | As of the closing date, the estimated fair values of the assets purchased and liabilities assumed by IPL were as follows (in millions): Electric plant in service $40 Current assets 2 Total assets acquired 42 Other liabilities 10 Net assets acquired $32 |
Receivables (Tables)
Receivables (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Receivables [Line Items] | |
Maximum And Average Outstanding Cash Proceeds | IPL’s maximum and average outstanding cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Maximum outstanding aggregate cash proceeds $112.0 $172.0 $112.0 $172.0 Average outstanding aggregate cash proceeds 66.2 112.3 58.7 91.5 |
Receivables Sold Under The Receivables Agreement | The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2017 December 31, 2016 Customer accounts receivable $153.6 $157.6 Unbilled utility revenues 89.1 90.4 Other receivables 1.1 0.1 Receivables sold to third party 243.8 248.1 Less: cash proceeds (a) 112.0 21.0 Deferred proceeds 131.8 227.1 Less: allowance for doubtful accounts 16.5 16.0 Fair value of deferred proceeds $115.3 $211.1 (a) Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements. |
Additional Attributes Of Receivables Sold Under The Receivables Agreement | Additional attributes of IPL’s receivables sold under the Receivables Agreement for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Collections reinvested in receivables $347.9 $499.7 $1,283.2 $1,362.1 Write-off losses (recoveries), net 3.5 (0.3 ) 10.4 (0.6 ) |
IPL [Member] | |
Receivables [Line Items] | |
Maximum And Average Outstanding Cash Proceeds | IPL’s maximum and average outstanding cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Maximum outstanding aggregate cash proceeds $112.0 $172.0 $112.0 $172.0 Average outstanding aggregate cash proceeds 66.2 112.3 58.7 91.5 |
Receivables Sold Under The Receivables Agreement | The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2017 December 31, 2016 Customer accounts receivable $153.6 $157.6 Unbilled utility revenues 89.1 90.4 Other receivables 1.1 0.1 Receivables sold to third party 243.8 248.1 Less: cash proceeds (a) 112.0 21.0 Deferred proceeds 131.8 227.1 Less: allowance for doubtful accounts 16.5 16.0 Fair value of deferred proceeds $115.3 $211.1 (a) Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements. |
Additional Attributes Of Receivables Sold Under The Receivables Agreement | Additional attributes of IPL’s receivables sold under the Receivables Agreement for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 Collections reinvested in receivables $347.9 $499.7 $1,283.2 $1,362.1 Write-off losses (recoveries), net 3.5 (0.3 ) 10.4 (0.6 ) |
Investments (Tables)
Investments (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Schedule of Investments [Line Items] | |
Unconsolidated Equity Investments | Equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and nine months ended September 30 was as follows (in millions): Alliant Energy WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 ATC Investment ($10.1 ) ($9.1 ) ($32.7 ) ($28.6 ) $— ($9.1 ) $— ($28.6 ) Other — (0.1 ) (0.2 ) (0.2 ) (0.2 ) (0.2 ) (0.4 ) (0.4 ) ($10.1 ) ($9.2 ) ($32.9 ) ($28.8 ) ($0.2 ) ($9.3 ) ($0.4 ) ($29.0 ) |
WPL [Member] | |
Schedule of Investments [Line Items] | |
Unconsolidated Equity Investments | Equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and nine months ended September 30 was as follows (in millions): Alliant Energy WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 ATC Investment ($10.1 ) ($9.1 ) ($32.7 ) ($28.6 ) $— ($9.1 ) $— ($28.6 ) Other — (0.1 ) (0.2 ) (0.2 ) (0.2 ) (0.2 ) (0.4 ) (0.4 ) ($10.1 ) ($9.2 ) ($32.9 ) ($28.8 ) ($0.2 ) ($9.3 ) ($0.4 ) ($29.0 ) |
Common Equity (Tables)
Common Equity (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Stockholders' Equity Note [Abstract] | |
Common Share Activity | A summary of Alliant Energy’s common stock activity was as follows: Shares outstanding, January 1, 2017 227,673,654 At-the-market offering program 3,074,931 Shareowner Direct Plan issuances 496,437 Equity-based compensation plans ( Note 9(b) ) 5,185 Other (45,847 ) Shares outstanding, September 30, 2017 231,204,360 |
Debt (Tables)
Debt (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Debt Disclosure [Line Items] | |
Other Short-Term Borrowings | Information regarding commercial paper classified as short-term debt was as follows (dollars in millions): September 30, 2017 Alliant Energy IPL WPL Commercial paper outstanding $390.3 $4.0 $224.6 Commercial paper weighted average interest rates 1.2% 1.4% 1.1% Available credit facility capacity (a) $569.7 $256.0 $175.4 Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $55.4 Average amount outstanding (based on daily outstanding balances) $386.2 $220.1 $0.4 $0.1 $217.0 $36.4 Weighted average interest rates 1.3% 0.6% 1.4% 0.6% 1.1% 0.4% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $62.9 Average amount outstanding (based on daily outstanding balances) $323.9 $210.7 $0.5 $— $144.2 $33.2 Weighted average interest rates 1.1% 0.6% 1.2% 0.6% 1.0% 0.4% (a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017 . |
IPL [Member] | |
Debt Disclosure [Line Items] | |
Other Short-Term Borrowings | Information regarding commercial paper classified as short-term debt was as follows (dollars in millions): September 30, 2017 Alliant Energy IPL WPL Commercial paper outstanding $390.3 $4.0 $224.6 Commercial paper weighted average interest rates 1.2% 1.4% 1.1% Available credit facility capacity (a) $569.7 $256.0 $175.4 Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $55.4 Average amount outstanding (based on daily outstanding balances) $386.2 $220.1 $0.4 $0.1 $217.0 $36.4 Weighted average interest rates 1.3% 0.6% 1.4% 0.6% 1.1% 0.4% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $62.9 Average amount outstanding (based on daily outstanding balances) $323.9 $210.7 $0.5 $— $144.2 $33.2 Weighted average interest rates 1.1% 0.6% 1.2% 0.6% 1.0% 0.4% (a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017 . |
WPL [Member] | |
Debt Disclosure [Line Items] | |
Other Short-Term Borrowings | Information regarding commercial paper classified as short-term debt was as follows (dollars in millions): September 30, 2017 Alliant Energy IPL WPL Commercial paper outstanding $390.3 $4.0 $224.6 Commercial paper weighted average interest rates 1.2% 1.4% 1.1% Available credit facility capacity (a) $569.7 $256.0 $175.4 Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $55.4 Average amount outstanding (based on daily outstanding balances) $386.2 $220.1 $0.4 $0.1 $217.0 $36.4 Weighted average interest rates 1.3% 0.6% 1.4% 0.6% 1.1% 0.4% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $424.4 $248.0 $20.0 $3.1 $271.2 $62.9 Average amount outstanding (based on daily outstanding balances) $323.9 $210.7 $0.5 $— $144.2 $33.2 Weighted average interest rates 1.1% 0.6% 1.2% 0.6% 1.0% 0.4% (a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017 . |
Income Taxes (Tables)
Income Taxes (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Income Taxes [Line Items] | |
Schedule Of Effective Income Tax Rates | The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes. Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (10.1 ) (11.9 ) (22.6 ) (16.5 ) (1.9 ) (0.7 ) IPL’s tax benefit riders (8.3 ) (13.1 ) (20.9 ) (20.1 ) — — Production tax credits (6.2 ) (9.0 ) (7.0 ) (6.0 ) (7.0 ) (5.7 ) Other items, net 2.8 4.4 2.3 5.4 5.5 4.0 Overall income tax rate 13.2 % 5.4 % (13.2 %) (2.2 %) 31.6 % 32.6 % Alliant Energy IPL WPL Nine Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (9.1 ) (8.2 ) (20.6 ) (14.8 ) (1.8 ) (0.8 ) IPL’s tax benefit riders (8.1 ) (10.2 ) (20.1 ) (19.6 ) — — Production tax credits (6.0 ) (7.2 ) (6.8 ) (6.1 ) (7.0 ) (6.1 ) Other items, net 3.1 3.5 2.7 4.2 4.9 4.4 Overall income tax rate 14.9 % 12.9 % (9.8 %) (1.3 %) 31.1 % 32.5 % |
Summary Of Tax Credit Carryforwards | At September 30, 2017 , carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2030-2037 $815 $500 $208 State net operating losses 2018-2037 701 14 2 Federal tax credits 2022-2037 297 110 125 |
IPL [Member] | |
Income Taxes [Line Items] | |
Schedule Of Effective Income Tax Rates | The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes. Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (10.1 ) (11.9 ) (22.6 ) (16.5 ) (1.9 ) (0.7 ) IPL’s tax benefit riders (8.3 ) (13.1 ) (20.9 ) (20.1 ) — — Production tax credits (6.2 ) (9.0 ) (7.0 ) (6.0 ) (7.0 ) (5.7 ) Other items, net 2.8 4.4 2.3 5.4 5.5 4.0 Overall income tax rate 13.2 % 5.4 % (13.2 %) (2.2 %) 31.6 % 32.6 % Alliant Energy IPL WPL Nine Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (9.1 ) (8.2 ) (20.6 ) (14.8 ) (1.8 ) (0.8 ) IPL’s tax benefit riders (8.1 ) (10.2 ) (20.1 ) (19.6 ) — — Production tax credits (6.0 ) (7.2 ) (6.8 ) (6.1 ) (7.0 ) (6.1 ) Other items, net 3.1 3.5 2.7 4.2 4.9 4.4 Overall income tax rate 14.9 % 12.9 % (9.8 %) (1.3 %) 31.1 % 32.5 % |
Summary Of Tax Credit Carryforwards | At September 30, 2017 , carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2030-2037 $815 $500 $208 State net operating losses 2018-2037 701 14 2 Federal tax credits 2022-2037 297 110 125 |
WPL [Member] | |
Income Taxes [Line Items] | |
Schedule Of Effective Income Tax Rates | The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes. Alliant Energy IPL WPL Three Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (10.1 ) (11.9 ) (22.6 ) (16.5 ) (1.9 ) (0.7 ) IPL’s tax benefit riders (8.3 ) (13.1 ) (20.9 ) (20.1 ) — — Production tax credits (6.2 ) (9.0 ) (7.0 ) (6.0 ) (7.0 ) (5.7 ) Other items, net 2.8 4.4 2.3 5.4 5.5 4.0 Overall income tax rate 13.2 % 5.4 % (13.2 %) (2.2 %) 31.6 % 32.6 % Alliant Energy IPL WPL Nine Months Ended September 30 2017 2016 2017 2016 2017 2016 Statutory federal income tax rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Effect of rate-making on property-related differences (9.1 ) (8.2 ) (20.6 ) (14.8 ) (1.8 ) (0.8 ) IPL’s tax benefit riders (8.1 ) (10.2 ) (20.1 ) (19.6 ) — — Production tax credits (6.0 ) (7.2 ) (6.8 ) (6.1 ) (7.0 ) (6.1 ) Other items, net 3.1 3.5 2.7 4.2 4.9 4.4 Overall income tax rate 14.9 % 12.9 % (9.8 %) (1.3 %) 31.1 % 32.5 % |
Summary Of Tax Credit Carryforwards | At September 30, 2017 , carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2030-2037 $815 $500 $208 State net operating losses 2018-2037 701 14 2 Federal tax credits 2022-2037 297 110 125 |
Benefit Plans (Tables)
Benefit Plans (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Defined Benefit Plan Disclosure [Line Items] | |
Defined Benefit Pension And Other Postretirement Benefits Plans | The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and nine months ended September 30 are included in the tables below (in millions). In IPL’s and WPL’s tables below, the defined benefit pension plan amounts represent those respective amounts for their bargaining unit employees covered under the qualified plans that they sponsor, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans. In IPL’s and WPL’s tables below, the OPEB plans amounts represent respective amounts for their employees, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Corporate Services sponsored OPEB plan. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $3.1 $3.2 $9.3 $9.5 $1.2 $1.4 $3.7 $4.0 Interest cost 12.7 13.2 38.3 39.7 2.2 2.3 6.5 7.0 Expected return on plan assets (16.3 ) (16.3 ) (49.1 ) (49.1 ) (1.5 ) (1.6 ) (4.6 ) (4.6 ) Amortization of prior service credit (0.1 ) (0.1 ) (0.3 ) (0.2 ) (0.1 ) (1.0 ) (0.2 ) (3.1 ) Amortization of actuarial loss 9.4 9.3 28.2 28.0 1.0 1.2 2.9 3.6 Settlement losses (a) 0.9 — 0.9 — — — — — $9.7 $9.3 $27.3 $27.9 $2.8 $2.3 $8.3 $6.9 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.8 $1.8 $5.5 $5.6 $0.5 $0.5 $1.6 $1.7 Interest cost 5.9 6.1 17.6 18.4 0.8 1.0 2.6 2.9 Expected return on plan assets (7.7 ) (7.7 ) (23.1 ) (23.2 ) (1.0 ) (1.0 ) (3.2 ) (3.2 ) Amortization of prior service credit — — (0.1 ) (0.1 ) — (0.7 ) — (2.0 ) Amortization of actuarial loss 4.0 4.2 12.1 12.4 0.5 0.7 1.5 2.0 $4.0 $4.4 $12.0 $13.1 $0.8 $0.5 $2.5 $1.4 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.2 $1.3 $3.6 $3.7 $0.5 $0.5 $1.4 $1.5 Interest cost 5.5 5.5 16.4 16.7 0.9 0.9 2.6 2.8 Expected return on plan assets (7.2 ) (7.0 ) (21.4 ) (21.2 ) (0.2 ) (0.2 ) (0.6 ) (0.6 ) Amortization of prior service cost (credit) 0.1 — 0.1 0.1 (0.1 ) (0.3 ) (0.2 ) (0.7 ) Amortization of actuarial loss 4.6 4.4 13.9 13.2 0.4 0.5 1.2 1.4 $4.2 $4.2 $12.6 $12.5 $1.5 $1.4 $4.4 $4.4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. |
Recognized Compensation Expense And Income Tax Benefits | A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and nine months ended September 30 was as follows (in millions): Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 Compensation expense $5.1 $4.4 $9.9 $16.8 $2.8 $2.4 $5.4 $8.9 $2.1 $1.9 $4.1 $7.3 Income tax benefits 2.1 1.7 4.0 6.8 1.1 1.0 2.2 3.7 0.9 0.7 1.7 2.9 |
Performance Shares and Performance Units [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Schedule Of Equity-based Compensation Plans Activity | A summary of the performance shares and performance units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of awards, was as follows: Performance Shares Performance Units Nonvested awards, January 1 257,599 93,320 Granted 65,350 21,558 Vested (99,438 ) (37,395 ) Forfeited — (4,243 ) Nonvested awards, September 30 223,511 73,240 Vested Awards - During the nine months ended September 30 , 2017 , certain performance shares and performance units that were granted in 2014 vested, resulting in payouts (a combination of cash and common stock for the performance shares and cash only for the performance units) as follows: Performance Shares Performance Units Performance awards vested 99,438 37,395 Percentage of target number of performance awards 147.5 % 147.5 % Aggregate payout value (in millions) $5.6 $1.5 Payout - cash (in millions) $5.1 $1.5 Payout - common stock shares issued 5,185 N/A Fair Value of Awards - Information related to fair values of nonvested performance shares and performance units at September 30, 2017 , by year of grant, was as follows: Performance Shares Performance Units 2017 Grant 2016 Grant 2015 Grant 2017 Grant 2016 Grant 2015 Grant Nonvested awards at target 65,350 67,355 90,806 19,531 21,751 31,958 Alliant Energy common stock closing price on September 29, 2017 $41.57 $41.57 $41.57 $41.57 $41.57 N/A Alliant Energy common stock closing price on grant date N/A N/A N/A N/A N/A $32.55 Estimated payout percentage based on performance criteria 100 % 138 % 113 % 100 % 138 % 113 % Fair values of each nonvested award $41.57 $57.37 $46.97 $41.57 $57.37 $36.78 |
Performance Restricted Stock Unit [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Schedule Of Equity-based Compensation Plans Activity | A summary of the performance restricted stock units activity for the nine months ended September 30 , 2017 , with amounts representing the target number of units, was as follows: Units Weighted Average Grant Date Fair Value Nonvested units, January 1 67,355 $33.96 Granted 65,350 39.12 Nonvested units, September 30 132,705 36.50 |
Restricted Stock Unit [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Schedule Of Equity-based Compensation Plans Activity | A summary of the restricted stock units activity for the nine months ended September 30 , 2017 , was as follows: Nonvested units, January 1 57,736 Granted 56,013 Nonvested units, September 30 113,749 |
IPL [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Defined Benefit Pension And Other Postretirement Benefits Plans | The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and nine months ended September 30 are included in the tables below (in millions). In IPL’s and WPL’s tables below, the defined benefit pension plan amounts represent those respective amounts for their bargaining unit employees covered under the qualified plans that they sponsor, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans. In IPL’s and WPL’s tables below, the OPEB plans amounts represent respective amounts for their employees, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Corporate Services sponsored OPEB plan. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $3.1 $3.2 $9.3 $9.5 $1.2 $1.4 $3.7 $4.0 Interest cost 12.7 13.2 38.3 39.7 2.2 2.3 6.5 7.0 Expected return on plan assets (16.3 ) (16.3 ) (49.1 ) (49.1 ) (1.5 ) (1.6 ) (4.6 ) (4.6 ) Amortization of prior service credit (0.1 ) (0.1 ) (0.3 ) (0.2 ) (0.1 ) (1.0 ) (0.2 ) (3.1 ) Amortization of actuarial loss 9.4 9.3 28.2 28.0 1.0 1.2 2.9 3.6 Settlement losses (a) 0.9 — 0.9 — — — — — $9.7 $9.3 $27.3 $27.9 $2.8 $2.3 $8.3 $6.9 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.8 $1.8 $5.5 $5.6 $0.5 $0.5 $1.6 $1.7 Interest cost 5.9 6.1 17.6 18.4 0.8 1.0 2.6 2.9 Expected return on plan assets (7.7 ) (7.7 ) (23.1 ) (23.2 ) (1.0 ) (1.0 ) (3.2 ) (3.2 ) Amortization of prior service credit — — (0.1 ) (0.1 ) — (0.7 ) — (2.0 ) Amortization of actuarial loss 4.0 4.2 12.1 12.4 0.5 0.7 1.5 2.0 $4.0 $4.4 $12.0 $13.1 $0.8 $0.5 $2.5 $1.4 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.2 $1.3 $3.6 $3.7 $0.5 $0.5 $1.4 $1.5 Interest cost 5.5 5.5 16.4 16.7 0.9 0.9 2.6 2.8 Expected return on plan assets (7.2 ) (7.0 ) (21.4 ) (21.2 ) (0.2 ) (0.2 ) (0.6 ) (0.6 ) Amortization of prior service cost (credit) 0.1 — 0.1 0.1 (0.1 ) (0.3 ) (0.2 ) (0.7 ) Amortization of actuarial loss 4.6 4.4 13.9 13.2 0.4 0.5 1.2 1.4 $4.2 $4.2 $12.6 $12.5 $1.5 $1.4 $4.4 $4.4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. |
Recognized Compensation Expense And Income Tax Benefits | A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and nine months ended September 30 was as follows (in millions): Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 Compensation expense $5.1 $4.4 $9.9 $16.8 $2.8 $2.4 $5.4 $8.9 $2.1 $1.9 $4.1 $7.3 Income tax benefits 2.1 1.7 4.0 6.8 1.1 1.0 2.2 3.7 0.9 0.7 1.7 2.9 |
WPL [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Defined Benefit Pension And Other Postretirement Benefits Plans | The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and nine months ended September 30 are included in the tables below (in millions). In IPL’s and WPL’s tables below, the defined benefit pension plan amounts represent those respective amounts for their bargaining unit employees covered under the qualified plans that they sponsor, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans. In IPL’s and WPL’s tables below, the OPEB plans amounts represent respective amounts for their employees, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Corporate Services sponsored OPEB plan. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $3.1 $3.2 $9.3 $9.5 $1.2 $1.4 $3.7 $4.0 Interest cost 12.7 13.2 38.3 39.7 2.2 2.3 6.5 7.0 Expected return on plan assets (16.3 ) (16.3 ) (49.1 ) (49.1 ) (1.5 ) (1.6 ) (4.6 ) (4.6 ) Amortization of prior service credit (0.1 ) (0.1 ) (0.3 ) (0.2 ) (0.1 ) (1.0 ) (0.2 ) (3.1 ) Amortization of actuarial loss 9.4 9.3 28.2 28.0 1.0 1.2 2.9 3.6 Settlement losses (a) 0.9 — 0.9 — — — — — $9.7 $9.3 $27.3 $27.9 $2.8 $2.3 $8.3 $6.9 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.8 $1.8 $5.5 $5.6 $0.5 $0.5 $1.6 $1.7 Interest cost 5.9 6.1 17.6 18.4 0.8 1.0 2.6 2.9 Expected return on plan assets (7.7 ) (7.7 ) (23.1 ) (23.2 ) (1.0 ) (1.0 ) (3.2 ) (3.2 ) Amortization of prior service credit — — (0.1 ) (0.1 ) — (0.7 ) — (2.0 ) Amortization of actuarial loss 4.0 4.2 12.1 12.4 0.5 0.7 1.5 2.0 $4.0 $4.4 $12.0 $13.1 $0.8 $0.5 $2.5 $1.4 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2017 2016 2017 2016 2017 2016 2017 2016 Service cost $1.2 $1.3 $3.6 $3.7 $0.5 $0.5 $1.4 $1.5 Interest cost 5.5 5.5 16.4 16.7 0.9 0.9 2.6 2.8 Expected return on plan assets (7.2 ) (7.0 ) (21.4 ) (21.2 ) (0.2 ) (0.2 ) (0.6 ) (0.6 ) Amortization of prior service cost (credit) 0.1 — 0.1 0.1 (0.1 ) (0.3 ) (0.2 ) (0.7 ) Amortization of actuarial loss 4.6 4.4 13.9 13.2 0.4 0.5 1.2 1.4 $4.2 $4.2 $12.6 $12.5 $1.5 $1.4 $4.4 $4.4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. |
Recognized Compensation Expense And Income Tax Benefits | A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and nine months ended September 30 was as follows (in millions): Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 Compensation expense $5.1 $4.4 $9.9 $16.8 $2.8 $2.4 $5.4 $8.9 $2.1 $1.9 $4.1 $7.3 Income tax benefits 2.1 1.7 4.0 6.8 1.1 1.0 2.2 3.7 0.9 0.7 1.7 2.9 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Statement [Line Items] | |
Fair Value Measurements | Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions): Alliant Energy September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $29.4 $— $2.9 $26.5 $29.4 $41.4 $— $4.6 $36.8 $41.4 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 45.1 — 14.9 30.2 45.1 28.6 — 0.5 28.1 28.6 Long-term debt (incl. current maturities) 4,360.3 — 4,893.3 2.9 4,896.2 4,320.2 — 4,795.7 3.3 4,799.0 Cumulative preferred stock of IPL 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 IPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $21.1 $— $1.6 $19.5 $21.1 $20.8 $— $2.8 $18.0 $20.8 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 18.7 — 4.5 14.2 18.7 8.3 — 0.4 7.9 8.3 Long-term debt (incl. current maturities) 2,195.0 — 2,430.1 — 2,430.1 2,153.5 — 2,352.3 — 2,352.3 Cumulative preferred stock 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 WPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $8.3 $— $1.3 $7.0 $8.3 $20.6 $— $1.8 $18.8 $20.6 Liabilities: Derivatives 26.4 — 10.4 16.0 26.4 20.3 — 0.1 20.2 20.3 Long-term debt 1,536.2 — 1,829.3 — 1,829.3 1,535.2 — 1,807.4 — 1,807.4 |
Fair Value Measurements Using Significant Unobservable Inputs | Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions): Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $9.2 $0.6 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.3 ) (5.1 ) — — Transfers out of Level 3 — 0.8 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (8.5 ) (4.0 ) (54.7 ) 165.3 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.2 ) ($5.0 ) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $8.7 ($32.7 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (31.3 ) 8.0 — — Transfers into Level 3 — 0.9 — — Transfers out of Level 3 12.2 1.2 — — Purchases 28.3 22.0 — — Sales (0.3 ) (0.9 ) — — Settlements (a) (21.3 ) (6.4 ) (95.8 ) 67.7 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($29.4 ) $9.7 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $17.1 $18.3 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.4 ) (0.4 ) — — Transfers out of Level 3 — 0.3 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (7.3 ) (4.6 ) (54.7 ) 165.3 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.5 ) ($0.4 ) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $10.1 ($1.9 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (13.9 ) 4.8 — — Transfers into Level 3 — 0.5 — — Transfers out of Level 3 3.1 0.2 — — Purchases 24.6 20.6 — — Sales (0.2 ) (0.9 ) — — Settlements (a) (18.4 ) (9.9 ) (95.8 ) 67.7 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($12.6 ) $5.7 $— $— WPL Commodity Contract Derivative Assets and (Liabilities), net Three Months Ended September 30 2017 2016 Beginning balance, July 1 ($7.9 ) ($17.7 ) Total net gains (losses) included in changes in net assets (realized/unrealized) 0.1 (4.7 ) Transfers out of Level 3 — 0.5 Settlements (1.2 ) 0.6 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 $0.3 ($4.6 ) WPL Commodity Contract Derivative Assets and (Liabilities), net Nine Months Ended September 30 2017 2016 Beginning balance, January 1 ($1.4 ) ($30.8 ) Total net gains (losses) included in changes in net assets (realized/unrealized) (17.4 ) 3.2 Transfers into Level 3 — 0.4 Transfers out of Level 3 9.1 1.0 Purchases 3.7 1.4 Sales (0.1 ) — Settlements (2.9 ) 3.5 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($16.8 ) $4.0 (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold. |
Fair Value Of Net Derivative Assets (Liabilities) | The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2017 ($22.2 ) $18.5 ($10.4 ) $15.7 ($11.8 ) $2.8 December 31, 2016 (2.3 ) 11.0 0.1 10.0 (2.4 ) 1.0 |
IPL [Member] | |
Statement [Line Items] | |
Fair Value Measurements | Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions): Alliant Energy September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $29.4 $— $2.9 $26.5 $29.4 $41.4 $— $4.6 $36.8 $41.4 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 45.1 — 14.9 30.2 45.1 28.6 — 0.5 28.1 28.6 Long-term debt (incl. current maturities) 4,360.3 — 4,893.3 2.9 4,896.2 4,320.2 — 4,795.7 3.3 4,799.0 Cumulative preferred stock of IPL 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 IPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $21.1 $— $1.6 $19.5 $21.1 $20.8 $— $2.8 $18.0 $20.8 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 18.7 — 4.5 14.2 18.7 8.3 — 0.4 7.9 8.3 Long-term debt (incl. current maturities) 2,195.0 — 2,430.1 — 2,430.1 2,153.5 — 2,352.3 — 2,352.3 Cumulative preferred stock 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 WPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $8.3 $— $1.3 $7.0 $8.3 $20.6 $— $1.8 $18.8 $20.6 Liabilities: Derivatives 26.4 — 10.4 16.0 26.4 20.3 — 0.1 20.2 20.3 Long-term debt 1,536.2 — 1,829.3 — 1,829.3 1,535.2 — 1,807.4 — 1,807.4 |
Fair Value Measurements Using Significant Unobservable Inputs | Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions): Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $9.2 $0.6 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.3 ) (5.1 ) — — Transfers out of Level 3 — 0.8 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (8.5 ) (4.0 ) (54.7 ) 165.3 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.2 ) ($5.0 ) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $8.7 ($32.7 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (31.3 ) 8.0 — — Transfers into Level 3 — 0.9 — — Transfers out of Level 3 12.2 1.2 — — Purchases 28.3 22.0 — — Sales (0.3 ) (0.9 ) — — Settlements (a) (21.3 ) (6.4 ) (95.8 ) 67.7 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($29.4 ) $9.7 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $17.1 $18.3 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.4 ) (0.4 ) — — Transfers out of Level 3 — 0.3 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (7.3 ) (4.6 ) (54.7 ) 165.3 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.5 ) ($0.4 ) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $10.1 ($1.9 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (13.9 ) 4.8 — — Transfers into Level 3 — 0.5 — — Transfers out of Level 3 3.1 0.2 — — Purchases 24.6 20.6 — — Sales (0.2 ) (0.9 ) — — Settlements (a) (18.4 ) (9.9 ) (95.8 ) 67.7 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($12.6 ) $5.7 $— $— WPL Commodity Contract Derivative Assets and (Liabilities), net Three Months Ended September 30 2017 2016 Beginning balance, July 1 ($7.9 ) ($17.7 ) Total net gains (losses) included in changes in net assets (realized/unrealized) 0.1 (4.7 ) Transfers out of Level 3 — 0.5 Settlements (1.2 ) 0.6 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 $0.3 ($4.6 ) WPL Commodity Contract Derivative Assets and (Liabilities), net Nine Months Ended September 30 2017 2016 Beginning balance, January 1 ($1.4 ) ($30.8 ) Total net gains (losses) included in changes in net assets (realized/unrealized) (17.4 ) 3.2 Transfers into Level 3 — 0.4 Transfers out of Level 3 9.1 1.0 Purchases 3.7 1.4 Sales (0.1 ) — Settlements (2.9 ) 3.5 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($16.8 ) $4.0 (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold. |
Fair Value Of Net Derivative Assets (Liabilities) | The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2017 ($22.2 ) $18.5 ($10.4 ) $15.7 ($11.8 ) $2.8 December 31, 2016 (2.3 ) 11.0 0.1 10.0 (2.4 ) 1.0 |
WPL [Member] | |
Statement [Line Items] | |
Fair Value Measurements | Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions): Alliant Energy September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $29.4 $— $2.9 $26.5 $29.4 $41.4 $— $4.6 $36.8 $41.4 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 45.1 — 14.9 30.2 45.1 28.6 — 0.5 28.1 28.6 Long-term debt (incl. current maturities) 4,360.3 — 4,893.3 2.9 4,896.2 4,320.2 — 4,795.7 3.3 4,799.0 Cumulative preferred stock of IPL 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 IPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $21.1 $— $1.6 $19.5 $21.1 $20.8 $— $2.8 $18.0 $20.8 Deferred proceeds 115.3 — — 115.3 115.3 211.1 — — 211.1 211.1 Liabilities and equity: Derivatives 18.7 — 4.5 14.2 18.7 8.3 — 0.4 7.9 8.3 Long-term debt (incl. current maturities) 2,195.0 — 2,430.1 — 2,430.1 2,153.5 — 2,352.3 — 2,352.3 Cumulative preferred stock 200.0 202.3 — — 202.3 200.0 194.8 — — 194.8 WPL September 30, 2017 December 31, 2016 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $8.3 $— $1.3 $7.0 $8.3 $20.6 $— $1.8 $18.8 $20.6 Liabilities: Derivatives 26.4 — 10.4 16.0 26.4 20.3 — 0.1 20.2 20.3 Long-term debt 1,536.2 — 1,829.3 — 1,829.3 1,535.2 — 1,807.4 — 1,807.4 |
Fair Value Measurements Using Significant Unobservable Inputs | Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions): Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $9.2 $0.6 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.3 ) (5.1 ) — — Transfers out of Level 3 — 0.8 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (8.5 ) (4.0 ) (54.7 ) 165.3 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.2 ) ($5.0 ) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $8.7 ($32.7 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (31.3 ) 8.0 — — Transfers into Level 3 — 0.9 — — Transfers out of Level 3 12.2 1.2 — — Purchases 28.3 22.0 — — Sales (0.3 ) (0.9 ) — — Settlements (a) (21.3 ) (6.4 ) (95.8 ) 67.7 Ending balance, September 30 ($3.7 ) ($7.9 ) $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($29.4 ) $9.7 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2017 2016 2017 2016 Beginning balance, July 1 $17.1 $18.3 $170.0 $74.4 Total net losses included in changes in net assets (realized/unrealized) (4.4 ) (0.4 ) — — Transfers out of Level 3 — 0.3 — — Sales (0.1 ) (0.2 ) — — Settlements (a) (7.3 ) (4.6 ) (54.7 ) 165.3 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30 ($4.5 ) ($0.4 ) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2017 2016 2017 2016 Beginning balance, January 1 $10.1 ($1.9 ) $211.1 $172.0 Total net gains (losses) included in changes in net assets (realized/unrealized) (13.9 ) 4.8 — — Transfers into Level 3 — 0.5 — — Transfers out of Level 3 3.1 0.2 — — Purchases 24.6 20.6 — — Sales (0.2 ) (0.9 ) — — Settlements (a) (18.4 ) (9.9 ) (95.8 ) 67.7 Ending balance, September 30 $5.3 $13.4 $115.3 $239.7 The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($12.6 ) $5.7 $— $— WPL Commodity Contract Derivative Assets and (Liabilities), net Three Months Ended September 30 2017 2016 Beginning balance, July 1 ($7.9 ) ($17.7 ) Total net gains (losses) included in changes in net assets (realized/unrealized) 0.1 (4.7 ) Transfers out of Level 3 — 0.5 Settlements (1.2 ) 0.6 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 $0.3 ($4.6 ) WPL Commodity Contract Derivative Assets and (Liabilities), net Nine Months Ended September 30 2017 2016 Beginning balance, January 1 ($1.4 ) ($30.8 ) Total net gains (losses) included in changes in net assets (realized/unrealized) (17.4 ) 3.2 Transfers into Level 3 — 0.4 Transfers out of Level 3 9.1 1.0 Purchases 3.7 1.4 Sales (0.1 ) — Settlements (2.9 ) 3.5 Ending balance, September 30 ($9.0 ) ($21.3 ) The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30 ($16.8 ) $4.0 (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold. |
Fair Value Of Net Derivative Assets (Liabilities) | The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2017 ($22.2 ) $18.5 ($10.4 ) $15.7 ($11.8 ) $2.8 December 31, 2016 (2.3 ) 11.0 0.1 10.0 (2.4 ) 1.0 |
Derivative Instruments (Tables)
Derivative Instruments (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Derivative Instruments [Line Items] | |
Notional Amounts Of Derivative Instruments | As of September 30, 2017 , gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts, FTRs, coal contracts and diesel fuel contracts that were accounted for as commodity derivative instruments were as follows (units in thousands): Electricity FTRs Natural Gas Coal Diesel Fuel MWhs Years MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 1,645 2017-2018 14,745 2017-2018 173,234 2017-2026 4,963 2017-2019 7,308 2017-2019 IPL — — 9,219 2017-2018 79,561 2017-2026 1,820 2017-2019 — — WPL 1,645 2017-2018 5,526 2017-2018 93,673 2017-2026 3,143 2017-2018 7,308 2017-2019 |
Fair Value Of Financial Instruments | The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $26.7 $29.4 $20.3 $19.1 $6.4 $10.3 Non-current derivative assets 2.7 12.0 0.8 1.7 1.9 10.3 Current derivative liabilities 18.5 13.3 4.6 2.7 13.9 10.6 Non-current derivative liabilities 26.6 15.3 14.1 5.6 12.5 9.7 |
IPL [Member] | |
Derivative Instruments [Line Items] | |
Notional Amounts Of Derivative Instruments | As of September 30, 2017 , gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts, FTRs, coal contracts and diesel fuel contracts that were accounted for as commodity derivative instruments were as follows (units in thousands): Electricity FTRs Natural Gas Coal Diesel Fuel MWhs Years MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 1,645 2017-2018 14,745 2017-2018 173,234 2017-2026 4,963 2017-2019 7,308 2017-2019 IPL — — 9,219 2017-2018 79,561 2017-2026 1,820 2017-2019 — — WPL 1,645 2017-2018 5,526 2017-2018 93,673 2017-2026 3,143 2017-2018 7,308 2017-2019 |
Fair Value Of Financial Instruments | The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $26.7 $29.4 $20.3 $19.1 $6.4 $10.3 Non-current derivative assets 2.7 12.0 0.8 1.7 1.9 10.3 Current derivative liabilities 18.5 13.3 4.6 2.7 13.9 10.6 Non-current derivative liabilities 26.6 15.3 14.1 5.6 12.5 9.7 |
WPL [Member] | |
Derivative Instruments [Line Items] | |
Notional Amounts Of Derivative Instruments | As of September 30, 2017 , gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts, FTRs, coal contracts and diesel fuel contracts that were accounted for as commodity derivative instruments were as follows (units in thousands): Electricity FTRs Natural Gas Coal Diesel Fuel MWhs Years MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 1,645 2017-2018 14,745 2017-2018 173,234 2017-2026 4,963 2017-2019 7,308 2017-2019 IPL — — 9,219 2017-2018 79,561 2017-2026 1,820 2017-2019 — — WPL 1,645 2017-2018 5,526 2017-2018 93,673 2017-2026 3,143 2017-2018 7,308 2017-2019 |
Fair Value Of Financial Instruments | The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $26.7 $29.4 $20.3 $19.1 $6.4 $10.3 Non-current derivative assets 2.7 12.0 0.8 1.7 1.9 10.3 Current derivative liabilities 18.5 13.3 4.6 2.7 13.9 10.6 Non-current derivative liabilities 26.6 15.3 14.1 5.6 12.5 9.7 |
Commitments And Contingencies (
Commitments And Contingencies (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Commitments and Contingencies [Line Items] | |
Other Purchase Obligations | At September 30, 2017 , minimum future commitments related to these purchase obligations were as follows (in millions): Alliant Energy IPL WPL Purchased power (a) $1,278 $1,194 $84 Natural gas 847 422 425 Coal (b) 144 66 78 Other (c) 34 25 1 $2,303 $1,707 $588 (a) Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. (b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change. (c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017 . |
MGP Site Estimated Future Costs And Recorded Liabilities | At September 30, 2017 , estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions). At September 30, 2017 , such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $12 - $31 $10 - $27 Current and non-current environmental liabilities 16 14 |
IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Other Purchase Obligations | At September 30, 2017 , minimum future commitments related to these purchase obligations were as follows (in millions): Alliant Energy IPL WPL Purchased power (a) $1,278 $1,194 $84 Natural gas 847 422 425 Coal (b) 144 66 78 Other (c) 34 25 1 $2,303 $1,707 $588 (a) Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. (b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change. (c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017 . |
MGP Site Estimated Future Costs And Recorded Liabilities | At September 30, 2017 , estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions). At September 30, 2017 , such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $12 - $31 $10 - $27 Current and non-current environmental liabilities 16 14 |
WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Other Purchase Obligations | At September 30, 2017 , minimum future commitments related to these purchase obligations were as follows (in millions): Alliant Energy IPL WPL Purchased power (a) $1,278 $1,194 $84 Natural gas 847 422 425 Coal (b) 144 66 78 Other (c) 34 25 1 $2,303 $1,707 $588 (a) Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. (b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change. (c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017 . |
Segments Of Business (Tables)
Segments Of Business (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Segment Reporting Information [Line Items] | |
Schedule Of Segments Of Business | Certain financial information relating to Alliant Energy’s business segments is as follows. Intersegment revenues were not material to Alliant Energy’s operations. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm. Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2017 Operating revenues $840.6 $45.8 $11.2 $897.6 $9.3 $906.9 Operating income (loss) 232.6 (2.4 ) (7.7 ) 222.5 9.0 231.5 Net income (loss) attributable to Alliant Energy common shareowners 176.3 (7.5 ) 168.8 Three Months Ended September 30, 2016 Operating revenues $864.3 $39.5 $9.4 $913.2 $11.4 $924.6 Operating income (loss) 244.2 (3.7 ) 0.4 240.9 (78.3 ) 162.6 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 183.1 (54.3 ) 128.8 Loss from discontinued operations, net of tax — (0.4 ) (0.4 ) Net income (loss) 183.1 (54.7 ) 128.4 Utility (a) Non-Regulated, Alliant Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2017 Operating revenues $2,199.1 $262.7 $34.4 $2,496.2 $29.9 $2,526.1 Operating income (loss) 475.4 29.5 (6.8 ) 498.1 25.6 523.7 Amounts attributable to Alliant Energy common shareowners: Income from continuing operations, net of tax 353.5 8.6 362.1 Income from discontinued operations, net of tax — 1.4 1.4 Net income 353.5 10.0 363.5 Nine Months Ended September 30, 2016 Operating revenues $2,209.1 $248.7 $35.0 $2,492.8 $30.2 $2,523.0 Operating income (loss) 473.3 27.0 4.4 504.7 (67.6 ) 437.1 Amounts attributable to Alliant Energy common shareowners: Income (loss) from continuing operations, net of tax 350.3 (39.5 ) 310.8 Loss from discontinued operations, net of tax — (2.0 ) (2.0 ) Net income (loss) 350.3 (41.5 ) 308.8 (a) Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. |
IPL [Member] | |
Segment Reporting Information [Line Items] | |
Schedule Of Segments Of Business | Certain financial information relating to IPL’s business segments is as follows. Intersegment revenues were not material to IPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $489.0 $27.4 $11.0 $527.4 Operating income (loss) 138.3 (2.1 ) (4.4 ) 131.8 Earnings available for common stock 120.4 Three Months Ended September 30, 2016 Operating revenues $483.2 $23.9 $9.1 $516.2 Operating income (loss) 125.9 (1.4 ) 1.4 125.9 Earnings available for common stock 114.1 Nine Months Ended September 30, 2017 Operating revenues $1,217.6 $147.2 $33.3 $1,398.1 Operating income (loss) 234.5 14.7 (1.5 ) 247.7 Earnings available for common stock 200.4 Nine Months Ended September 30, 2016 Operating revenues $1,209.2 $142.6 $34.1 $1,385.9 Operating income 213.8 15.3 6.8 235.9 Earnings available for common stock 191.6 |
WPL [Member] | |
Segment Reporting Information [Line Items] | |
Schedule Of Segments Of Business | Certain financial information relating to WPL’s business segments is as follows. Intersegment revenues were not material to WPL’s operations. Electric Gas Other Total (in millions) Three Months Ended September 30, 2017 Operating revenues $351.6 $18.4 $0.2 $370.2 Operating income (loss) 94.3 (0.3 ) (3.3 ) 90.7 Earnings available for common stock 49.8 Three Months Ended September 30, 2016 Operating revenues $381.1 $15.6 $0.3 $397.0 Operating income (loss) 118.3 (2.3 ) (1.0 ) 115.0 Earnings available for common stock 69.0 Nine Months Ended September 30, 2017 Operating revenues $981.5 $115.5 $1.1 $1,098.1 Operating income (loss) 240.9 14.8 (5.3 ) 250.4 Earnings available for common stock 133.4 Nine Months Ended September 30, 2016 Operating revenues $999.9 $106.1 $0.9 $1,106.9 Operating income (loss) 259.5 11.7 (2.4 ) 268.8 Earnings available for common stock 158.7 |
Related Parties (Tables)
Related Parties (Tables) | 9 Months Ended |
Sep. 30, 2017 | |
Related Party Transactions [Line Items] | |
Services Provided, Sales Credited And Purchases | The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions): IPL WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 Corporate Services billings $48 $41 $130 $124 $37 $33 $100 $103 Sales credited 8 4 15 7 6 3 8 6 Purchases billed 109 126 271 324 32 23 99 65 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Net payables to Corporate Services $118 $104 $64 $72 |
Related Amounts Billed Between Parties | The related amounts billed between the parties for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 ATC LLC billings to WPL $26 $28 $79 $82 WPL billings to ATC LLC 2 4 8 10 |
IPL [Member] | |
Related Party Transactions [Line Items] | |
Services Provided, Sales Credited And Purchases | The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions): IPL WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 Corporate Services billings $48 $41 $130 $124 $37 $33 $100 $103 Sales credited 8 4 15 7 6 3 8 6 Purchases billed 109 126 271 324 32 23 99 65 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Net payables to Corporate Services $118 $104 $64 $72 |
WPL [Member] | |
Related Party Transactions [Line Items] | |
Services Provided, Sales Credited And Purchases | The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions): IPL WPL Three Months Nine Months Three Months Nine Months 2017 2016 2017 2016 2017 2016 2017 2016 Corporate Services billings $48 $41 $130 $124 $37 $33 $100 $103 Sales credited 8 4 15 7 6 3 8 6 Purchases billed 109 126 271 324 32 23 99 65 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 Net payables to Corporate Services $118 $104 $64 $72 |
Related Amounts Billed Between Parties | The related amounts billed between the parties for the three and nine months ended September 30 were as follows (in millions): Three Months Nine Months 2017 2016 2017 2016 ATC LLC billings to WPL $26 $28 $79 $82 WPL billings to ATC LLC 2 4 8 10 |
Regulatory Matters (Narrative)
Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended | ||||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Regulatory Matters [Line Items] | |||||||
Increase (decrease) in regulatory liabilities | $ 64.8 | $ 66.5 | |||||
Depreciation and amortization | $ 120.7 | $ 104.1 | 342.7 | 308.7 | |||
Regulatory liabilities | 628.5 | 628.5 | $ 681 | ||||
Regulatory assets | 2,036.5 | 2,036.5 | 1,915.1 | ||||
IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Increase (decrease) in regulatory liabilities | 49.6 | 64.5 | |||||
Other operation and maintenance | 104.4 | 94.8 | 288.7 | 279.8 | |||
Depreciation and amortization | 66.2 | 52.7 | 181 | 157.8 | |||
Regulatory liabilities | 384.8 | 384.8 | 430.8 | ||||
Regulatory assets | 1,590.9 | 1,590.9 | 1,458.8 | ||||
WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Other operation and maintenance | 66.1 | 54.2 | 179.7 | 157.2 | |||
Depreciation and amortization | 53.6 | $ 48.7 | 158.8 | $ 143.5 | |||
Regulatory liabilities | 243.7 | 243.7 | 250.2 | ||||
Regulatory assets | 445.6 | 445.6 | 456.3 | ||||
2016 Test Year Retail Electric [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Write-down of regulatory assets | 9 | ||||||
2016 Test Year Retail Electric [Member] | Alliant Energy and IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Increase in base rates | 34 | 54 | |||||
2017 and 2018 Test Period Retail Electric [Member] | Alliant Energy and WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Increase in base rates | 4 | 42 | |||||
2017 and 2018 Test Period Retail Gas [Member] | Alliant Energy and WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Increase in base rates | 2 | $ 6 | |||||
2016 Test Year Retail Electric Fuel-related [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Annual bandwidth for fuel-related costs | 2.00% | ||||||
2017 Test Year Retail Electric Fuel-related [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Annual bandwidth for fuel-related costs | 2.00% | ||||||
Scenario, Forecast [Member] | 2016 Test Year Retail Electric [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Requested rate increase (decrease), amount | $ 176 | ||||||
Requested rate increase (decrease), percent | 12.00% | ||||||
Interim rate increase (decrease), amount | $ 102 | ||||||
Interim rate increase (decrease), percent | 7.00% | ||||||
Settlement agreement rate increase, amount | $ 130 | ||||||
Settlement agreement rate increase, percent | 9.00% | ||||||
Scenario, Forecast [Member] | 2017 and 2018 Test Period Retail Electric [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Increase in base rates | $ 60 | ||||||
Authorized increase (decrease) in final rates, amount | $ 9 | ||||||
Authorized increase (decrease) in final rates, percent | 1.00% | ||||||
Reduction in fuel-related costs | $ 51 | ||||||
Scenario, Forecast [Member] | 2017 and 2018 Test Period Retail Gas [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Authorized increase (decrease) in final rates, amount | $ 9 | ||||||
Authorized increase (decrease) in final rates, percent | 13.00% | ||||||
Scenario, Forecast [Member] | 2018 Test Year Retail Electric Fuel-related [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Requested rate increase (decrease), amount | $ 6 | ||||||
Requested rate increase (decrease), percent | 1.00% | ||||||
FERC [Member] | MISO Transmission Owner Complaints [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Base return on equity for refund period from November 12, 2013 through February 11, 2015, percent | 10.32% | ||||||
Refund received, after final true-up | $ 50 | ||||||
FERC [Member] | MISO Transmission Owner Complaints [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Refund received, after final true-up | 39 | ||||||
FERC [Member] | MISO Transmission Owner Complaints [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Refund received, after final true-up | 11 | ||||||
Asset retirement obligations [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 107.9 | 107.9 | 105.9 | ||||
Asset retirement obligations [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 71.9 | 71.9 | 64.3 | ||||
Asset retirement obligations [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 36 | 36 | 41.6 | ||||
Asset retirement obligations [Member] | 2016 Test Year Retail Electric [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Depreciation and amortization | 5 | ||||||
Asset retirement obligations [Member] | IUB [Member] | Scenario, Forecast [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Requested recovery period | 4 years | ||||||
Other [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 90 | 90 | 76.6 | ||||
Other [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 51 | 51 | 41.9 | ||||
Other [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 39 | 39 | 34.7 | ||||
Other [Member] | 2017 Test Year Retail Electric Fuel-related [Member] | Alliant Energy and WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 3 | 3 | |||||
IPL's tax benefit riders [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory liabilities | 45 | 45 | 83.5 | ||||
IPL's tax benefit riders [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory liabilities | 45 | 45 | 83.5 | ||||
IPL's tax benefit riders [Member] | Alliant Energy and IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Increase (decrease) in regulatory liabilities | 17 | ||||||
Commodity cost recovery [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory liabilities | 21.2 | 21.2 | 30.8 | ||||
Commodity cost recovery [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory liabilities | 15 | 15 | 17.8 | ||||
Commodity cost recovery [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory liabilities | 6.2 | 6.2 | $ 13 | ||||
Commodity cost recovery [Member] | 2016 Test Year Retail Electric Fuel-related [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory liabilities | 3 | 3 | |||||
Commodity cost recovery [Member] | 2017 Test Year Retail Electric Fuel-related [Member] | WPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Regulatory assets | 6 | $ 6 | |||||
Sutherland Units 1 And 3 [Member] | 2016 Test Year Retail Electric [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Other operation and maintenance | $ 4 | ||||||
Sutherland Units 1 And 3 [Member] | IUB [Member] | Scenario, Forecast [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Requested recovery period | 10 years | ||||||
Sutherland Units 1 And 3 [Member] | FERC [Member] | IPL [Member] | |||||||
Regulatory Matters [Line Items] | |||||||
Requested recovery period | 10 years |
Regulatory Matters (Regulatory
Regulatory Matters (Regulatory Assets) (Details) - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 |
Regulatory Assets [Line Items] | ||
Regulatory assets | $ 2,036.5 | $ 1,915.1 |
Tax-related [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 1,147.9 | 1,055.6 |
Pension and OPEB costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 547.8 | 578.7 |
Asset retirement obligations [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 107.9 | 105.9 |
EGUs retired early [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 67.4 | 41.4 |
Derivatives [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 49.9 | 30.7 |
Emission allowances [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 25.6 | 26.2 |
Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 90 | 76.6 |
IPL [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 1,590.9 | 1,458.8 |
IPL [Member] | Tax-related [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 1,107.9 | 1,022.4 |
IPL [Member] | Pension and OPEB costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 279.3 | 294 |
IPL [Member] | Asset retirement obligations [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 71.9 | 64.3 |
IPL [Member] | EGUs retired early [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 32.9 | 0 |
IPL [Member] | Derivatives [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 22.3 | 10 |
IPL [Member] | Emission allowances [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 25.6 | 26.2 |
IPL [Member] | Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 51 | 41.9 |
WPL [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 445.6 | 456.3 |
WPL [Member] | Tax-related [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 40 | 33.2 |
WPL [Member] | Pension and OPEB costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 268.5 | 284.7 |
WPL [Member] | Asset retirement obligations [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 36 | 41.6 |
WPL [Member] | EGUs retired early [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 34.5 | 41.4 |
WPL [Member] | Derivatives [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 27.6 | 20.7 |
WPL [Member] | Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | $ 39 | $ 34.7 |
Regulatory Matters (Regulator36
Regulatory Matters (Regulatory Liabilities) (Details) - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 |
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | $ 628.5 | $ 681 |
Cost of removal obligations [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 412.1 | 411.6 |
Electric transmission cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 94.8 | 72 |
IPL's tax benefit riders [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 45 | 83.5 |
Commodity cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 21.2 | 30.8 |
Energy efficiency cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 20 | 20.5 |
Derivatives [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 10.9 | 31.5 |
Other [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 24.5 | 31.1 |
IPL [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 384.8 | 430.8 |
IPL [Member] | Cost of removal obligations [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 272.9 | 269.4 |
IPL [Member] | Electric transmission cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 35.9 | 35.7 |
IPL [Member] | IPL's tax benefit riders [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 45 | 83.5 |
IPL [Member] | Commodity cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 15 | 17.8 |
IPL [Member] | Derivatives [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 5.8 | 12.1 |
IPL [Member] | Other [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 10.2 | 12.3 |
WPL [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 243.7 | 250.2 |
WPL [Member] | Cost of removal obligations [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 139.2 | 142.2 |
WPL [Member] | Electric transmission cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 58.9 | 36.3 |
WPL [Member] | Commodity cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 6.2 | 13 |
WPL [Member] | Energy efficiency cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 20 | 20.5 |
WPL [Member] | Derivatives [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 5.1 | 19.4 |
WPL [Member] | Other [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | $ 14.3 | $ 18.8 |
Regulatory Matters (Tax Benefit
Regulatory Matters (Tax Benefit Riders) (Details) - USD ($) $ in Millions | 9 Months Ended | |
Sep. 30, 2017 | Sep. 30, 2016 | |
Regulatory Liabilities [Line Items] | ||
Increase (decrease) in regulatory liabilities | $ 64.8 | $ 66.5 |
Alliant Energy and IPL [Member] | Electric tax benefit rider [Member] | ||
Regulatory Liabilities [Line Items] | ||
Increase (decrease) in regulatory liabilities | (51) | |
Alliant Energy and IPL [Member] | Gas tax benefit rider [Member] | ||
Regulatory Liabilities [Line Items] | ||
Increase (decrease) in regulatory liabilities | (5) | |
Alliant Energy and IPL [Member] | Rate-making accounting change [Member] | ||
Regulatory Liabilities [Line Items] | ||
Increase (decrease) in regulatory liabilities | 17 | |
Alliant Energy and IPL [Member] | Tax benefit riders [Member] | ||
Regulatory Liabilities [Line Items] | ||
Increase (decrease) in regulatory liabilities | $ (39) |
Property, Plant and Equipment (
Property, Plant and Equipment (Narrative) (Details) $ / shares in Units, $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended | ||||
Jun. 30, 2018USD ($)MW | Sep. 30, 2017USD ($) | Sep. 30, 2016USD ($)$ / shares | Sep. 30, 2017USD ($)MW | Sep. 30, 2016USD ($) | Dec. 31, 2020MW | Apr. 30, 2017USD ($) | |
Property, Plant and Equipment [Line Items] | |||||||
Allowance for funds used during construction | $ 9.6 | $ 15.8 | $ 36.7 | $ 44.3 | |||
Asset valuation charges for Franklin County wind farm, pre-tax | 0 | 86.4 | 0 | 86.4 | |||
Asset valuation charge for Franklin County wind farm, after tax | $ 51 | ||||||
Asset valuation charges for Franklin County wind farm, after tax (in dollars per share) | $ / shares | $ 0.23 | ||||||
IPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Allowance for funds used during construction | 4.7 | $ 13.8 | 25.1 | 36.2 | |||
Estimated fair value of net assets acquired | $ 32 | ||||||
WPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Allowance for funds used during construction | 4.9 | $ 2 | $ 11.6 | $ 8.1 | |||
Marshalltown Generating Station [Member] | IPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Fossil-fueled EGU capacity (in megawatts) | MW | 660 | ||||||
Marshalltown Generating Station [Member] | Alliant Energy and IPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Total project costs | 643 | $ 643 | |||||
Allowance for funds used during construction | $ 81 | ||||||
West Riverside Energy Center [Member] | WPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Fossil-fueled EGU capacity (in megawatts) | MW | 730 | ||||||
West Riverside Energy Center [Member] | Alliant Energy and WPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Construction work in progress | 278 | $ 278 | |||||
Allowance for funds used during construction | $ 9 | ||||||
Expansion of Wind Generation [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Electric capacity of wind farm | MW | 129 | ||||||
Expansion of Wind Generation [Member] | Alliant Energy and IPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Construction work in progress | $ 184 | $ 184 | |||||
Allowance for funds used during construction | $ 7 | ||||||
Scenario, Forecast [Member] | Expansion of Wind Generation [Member] | IPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Electric capacity of wind farm | MW | 1,000 | ||||||
Scenario, Forecast [Member] | Expansion of Wind Generation [Member] | WPL [Member] | |||||||
Property, Plant and Equipment [Line Items] | |||||||
Electric capacity of wind farm | MW | 55 | ||||||
Estimated fair value of net assets acquired | $ 74 |
Property, Plant and Equipment39
Property, Plant and Equipment (Estimated Fair Value of Franklin County Wind Farm Assets and Liabilities Transferred) (Details) - IPL [Member] $ in Millions | Apr. 30, 2017USD ($) |
Property, Plant and Equipment [Line Items] | |
Electric plant in service | $ 40 |
Current assets | 2 |
Total assets acquired | 42 |
Other liabilities | 10 |
Net assets acquired | $ 32 |
Receivables (Narrative) (Detail
Receivables (Narrative) (Details) - Receivables Sold [Member] - IPL [Member] $ in Millions | Sep. 30, 2017USD ($) |
Receivables [Line Items] | |
Available capacity | $ 1.5 |
Outstanding receivables past due | $ 54.1 |
Receivables (Maximum And Averag
Receivables (Maximum And Average Outstanding Cash Proceeds) (Details) - IPL [Member] - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Receivables [Line Items] | ||||
Outstanding aggregate cash proceeds (based on daily outstanding balances) | $ 66.2 | $ 112.3 | $ 58.7 | $ 91.5 |
Maximum [Member] | ||||
Receivables [Line Items] | ||||
Outstanding aggregate cash proceeds (based on daily outstanding balances) | $ 112 | $ 172 | $ 112 | $ 172 |
Receivables (Receivables Sold U
Receivables (Receivables Sold Under The Agreement) (Details) - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 | |
Receivables [Line Items] | |||
Fair value of deferred proceeds | $ 115.3 | $ 211.1 | |
IPL [Member] | |||
Receivables [Line Items] | |||
Fair value of deferred proceeds | 115.3 | 211.1 | |
Receivables Sold [Member] | IPL [Member] | |||
Receivables [Line Items] | |||
Customer accounts receivable | 153.6 | 157.6 | |
Unbilled utility revenues | 89.1 | 90.4 | |
Other receivables | 1.1 | 0.1 | |
Receivables sold to third party | 243.8 | 248.1 | |
Less: cash proceeds | [1] | 112 | 21 |
Deferred proceeds | 131.8 | 227.1 | |
Less: allowance for doubtful accounts | 16.5 | 16 | |
Fair value of deferred proceeds | $ 115.3 | $ 211.1 | |
[1] | Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements. |
Receivables (Additional Attribu
Receivables (Additional Attributes Of Receivables Sold Under The Agreement) (Details) - IPL [Member] - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Receivables [Line Items] | ||||
Collections reinvested in receivables | $ 347.9 | $ 499.7 | $ 1,283.2 | $ 1,362.1 |
Write-off losses (recoveries), net | $ 3.5 | $ (0.3) | $ 10.4 | $ (0.6) |
Investments (Narrative) (Detail
Investments (Narrative) (Details) $ in Millions | 1 Months Ended | 9 Months Ended | |
Jul. 31, 2017USD ($) | Sep. 30, 2017USD ($)MW | Sep. 30, 2016USD ($) | |
Schedule of Investments [Line Items] | |||
Proceeds from liquidation of company-owned life insurance policies | $ 31 | ||
Alliant Energy Finance LLC [Member] | |||
Schedule of Investments [Line Items] | |||
Cash equity ownership interest, ownership percentage | 50.00% | ||
Electric capacity of wind farm | MW | 225 | ||
Increase in Other Investments assets from acquisition | $ 98 | ||
IPL [Member] | |||
Schedule of Investments [Line Items] | |||
Proceeds from liquidation of company-owned life insurance policies | $ 19 | ||
Term Loan Credit Agreement [Member] | Alliant Energy Finance LLC [Member] | |||
Schedule of Investments [Line Items] | |||
Proceeds from issuance of debt | $ 95 | ||
Variable-rate term loan credit agreement, period | 364 days |
Investments (Unconsolidated Equ
Investments (Unconsolidated Equity Investments) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Schedule of Investments [Line Items] | ||||
Equity (income) loss from unconsolidated investments, net | $ (10.1) | $ (9.2) | $ (32.9) | $ (28.8) |
WPL [Member] | ||||
Schedule of Investments [Line Items] | ||||
Equity (income) loss from unconsolidated investments, net | (0.2) | (9.3) | (0.4) | (29) |
ATC Investment [Member] | ||||
Schedule of Investments [Line Items] | ||||
Equity (income) loss from unconsolidated investments, net | (10.1) | (9.1) | (32.7) | (28.6) |
ATC Investment [Member] | WPL [Member] | ||||
Schedule of Investments [Line Items] | ||||
Equity (income) loss from unconsolidated investments, net | 0 | (9.1) | 0 | (28.6) |
Other [Member] | ||||
Schedule of Investments [Line Items] | ||||
Equity (income) loss from unconsolidated investments, net | 0 | (0.1) | (0.2) | (0.2) |
Other [Member] | WPL [Member] | ||||
Schedule of Investments [Line Items] | ||||
Equity (income) loss from unconsolidated investments, net | $ (0.2) | $ (0.2) | $ (0.4) | $ (0.4) |
Common Equity (Narrative) (Deta
Common Equity (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Common Equity [Line Items] | ||||
Proceeds from issuance of common stock, net | $ 143.2 | $ 20.4 | ||
Comprehensive income | $ 0 | $ 0 | 0 | 0 |
IPL [Member] | ||||
Common Equity [Line Items] | ||||
Retained earnings free of dividend restrictions | 701 | 701 | ||
Restricted net assets of subsidiaries | 1,700 | 1,700 | ||
Comprehensive income | 0 | 0 | 0 | 0 |
WPL [Member] | ||||
Common Equity [Line Items] | ||||
Retained earnings free of dividend restrictions | 32 | 32 | ||
Restricted net assets of subsidiaries | 1,800 | 1,800 | ||
Comprehensive income | $ 0 | $ 0 | 0 | $ 0 |
At-The-Market Offering Program [Member] | ||||
Common Equity [Line Items] | ||||
Maximum aggregate gross sales price of common stock that can be offered and sold | $ 125 | |||
At-the-market offering program issuances (in shares) | 3,074,931 | |||
Proceeds from issuance of common stock, net | $ 124 | |||
Commissions and fees from issuance of common stock | $ 1 |
Common Equity (Common Share Act
Common Equity (Common Share Activity) (Details) | 9 Months Ended |
Sep. 30, 2017shares | |
Common Stock Oustanding [Roll Forward] | |
Shares outstanding, January 1, 2017 (in shares) | 227,673,654 |
Shareowner Direct Plan issuances (in shares) | 496,437 |
Equity-based compensation plans (in shares) | 5,185 |
Other (in shares) | (45,847) |
Shares outstanding, September 30, 2017 (in shares) | 231,204,360 |
At-The-Market Offering Program [Member] | |
Common Stock Oustanding [Roll Forward] | |
At-the-market offering program (in shares) | 3,074,931 |
Debt (Narrative) (Details)
Debt (Narrative) (Details) - USD ($) $ in Millions | 1 Months Ended | |||
Oct. 31, 2017 | Jul. 31, 2017 | Dec. 31, 2017 | Sep. 30, 2017 | |
Debt [Line Items] | ||||
Line of credit facility, current borrowing capacity | $ 1,000 | |||
Parent Company [Member] | ||||
Debt [Line Items] | ||||
Line of credit facility, current borrowing capacity | 300 | |||
IPL [Member] | ||||
Debt [Line Items] | ||||
Line of credit facility, current borrowing capacity | 300 | |||
WPL [Member] | ||||
Debt [Line Items] | ||||
Line of credit facility, current borrowing capacity | 400 | |||
Alliant Energy and IPL [Member] | ||||
Debt [Line Items] | ||||
Commercial paper, long-term | $ 40 | |||
Commercial paper, long-term, interest rate | 1.40% | |||
Term Loan Credit Agreement [Member] | Alliant Energy Finance LLC [Member] | ||||
Debt [Line Items] | ||||
Proceeds from issuance of debt | $ 95 | |||
Variable-rate term loan credit agreement, period | 364 days | |||
Interest rate | 1.80% | |||
Subsequent Event [Member] | 3.05% debenture, due 2027 [Member] | Debentures [Member] | WPL [Member] | ||||
Debt [Line Items] | ||||
Proceeds from issuance of debt | $ 300 | |||
Interest rate | 3.05% | |||
Scenario, Forecast [Member] | Parent Company [Member] | ||||
Debt [Line Items] | ||||
Line of credit facility, maximum borrowing capacity | $ 500 | |||
Scenario, Forecast [Member] | IPL [Member] | ||||
Debt [Line Items] | ||||
Line of credit facility, maximum borrowing capacity | 400 | |||
Scenario, Forecast [Member] | WPL [Member] | ||||
Debt [Line Items] | ||||
Line of credit facility, maximum borrowing capacity | $ 500 |
Debt (Credit Facilities) (Detai
Debt (Credit Facilities) (Details) - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 | |
Debt [Line Items] | |||
Commercial paper outstanding | $ 390.3 | $ 244.1 | |
Commercial paper weighted average interest rates | 1.20% | ||
Available credit facility capacity | [1] | $ 569.7 | |
IPL [Member] | |||
Debt [Line Items] | |||
Commercial paper outstanding | $ 4 | 0 | |
Commercial paper weighted average interest rates | 1.40% | ||
Available credit facility capacity | [1] | $ 256 | |
WPL [Member] | |||
Debt [Line Items] | |||
Commercial paper outstanding | $ 224.6 | $ 52.3 | |
Commercial paper weighted average interest rates | 1.10% | ||
Available credit facility capacity | $ 175.4 | ||
[1] | Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017. |
Debt (Other Short-Term Borrowin
Debt (Other Short-Term Borrowings) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Debt [Line Items] | ||||
Maximum amount outstanding (based on daily outstanding balances) | $ 424.4 | $ 248 | $ 424.4 | $ 248 |
Average amount outstanding (based on daily outstanding balances) | $ 386.2 | $ 220.1 | $ 323.9 | $ 210.7 |
Weighted average interest rates | 1.30% | 0.60% | 1.10% | 0.60% |
IPL [Member] | ||||
Debt [Line Items] | ||||
Maximum amount outstanding (based on daily outstanding balances) | $ 20 | $ 3.1 | $ 20 | $ 3.1 |
Average amount outstanding (based on daily outstanding balances) | $ 0.4 | $ 0.1 | $ 0.5 | $ 0 |
Weighted average interest rates | 1.40% | 0.60% | 1.20% | 0.60% |
WPL [Member] | ||||
Debt [Line Items] | ||||
Maximum amount outstanding (based on daily outstanding balances) | $ 271.2 | $ 55.4 | $ 271.2 | $ 62.9 |
Average amount outstanding (based on daily outstanding balances) | $ 217 | $ 36.4 | $ 144.2 | $ 33.2 |
Weighted average interest rates | 1.10% | 0.40% | 1.00% | 0.40% |
Income Taxes (Narrative) (Detai
Income Taxes (Narrative) (Details) $ in Millions | 9 Months Ended |
Sep. 30, 2017USD ($) | |
Income Taxes [Line Items] | |
Increase in deferred tax liabilities | $ 204.5 |
IPL [Member] | |
Income Taxes [Line Items] | |
Increase in deferred tax liabilities | 131.7 |
WPL [Member] | |
Income Taxes [Line Items] | |
Increase in deferred tax liabilities | $ 63.6 |
Income Taxes (Schedule Of Effec
Income Taxes (Schedule Of Effective Income Tax Rates) (Details) | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Effective Tax Rate [Line Items] | ||||
Statutory federal income tax rate | 35.00% | 35.00% | 35.00% | 35.00% |
Effect of rate-making on property-related differences | (10.10%) | (11.90%) | (9.10%) | (8.20%) |
IPL's tax benefit riders | (8.30%) | (13.10%) | (8.10%) | (10.20%) |
Production tax credits | (6.20%) | (9.00%) | (6.00%) | (7.20%) |
Other items, net | 2.80% | 4.40% | 3.10% | 3.50% |
Overall income tax rate | 13.20% | 5.40% | 14.90% | 12.90% |
IPL [Member] | ||||
Effective Tax Rate [Line Items] | ||||
Statutory federal income tax rate | 35.00% | 35.00% | 35.00% | 35.00% |
Effect of rate-making on property-related differences | (22.60%) | (16.50%) | (20.60%) | (14.80%) |
IPL's tax benefit riders | (20.90%) | (20.10%) | (20.10%) | (19.60%) |
Production tax credits | (7.00%) | (6.00%) | (6.80%) | (6.10%) |
Other items, net | 2.30% | 5.40% | 2.70% | 4.20% |
Overall income tax rate | (13.20%) | (2.20%) | (9.80%) | (1.30%) |
WPL [Member] | ||||
Effective Tax Rate [Line Items] | ||||
Statutory federal income tax rate | 35.00% | 35.00% | 35.00% | 35.00% |
Effect of rate-making on property-related differences | (1.90%) | (0.70%) | (1.80%) | (0.80%) |
Production tax credits | (7.00%) | (5.70%) | (7.00%) | (6.10%) |
Other items, net | 5.50% | 4.00% | 4.90% | 4.40% |
Overall income tax rate | 31.60% | 32.60% | 31.10% | 32.50% |
Income Taxes (Summary Of Tax Cr
Income Taxes (Summary Of Tax Credit Carryforwards) (Details) $ in Millions | Sep. 30, 2017USD ($) |
Federal [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | $ 815 |
Tax credits, carryforward amount | 297 |
Federal [Member] | IPL [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 500 |
Tax credits, carryforward amount | 110 |
Federal [Member] | WPL [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 208 |
Tax credits, carryforward amount | 125 |
State [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 701 |
State [Member] | IPL [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 14 |
State [Member] | WPL [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | $ 2 |
Benefit Plans (Narrative) (Deta
Benefit Plans (Narrative) (Details) $ in Millions | 9 Months Ended |
Sep. 30, 2017USD ($) | |
Defined Benefit Plan Disclosure [Line Items] | |
Unrecognized compensation cost | $ 8.5 |
Minimum [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Unrecognized compensation cost recognized over a weighted average period | 1 year |
Maximum [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Unrecognized compensation cost recognized over a weighted average period | 2 years |
IPL [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Unrecognized compensation cost | $ 4.7 |
WPL [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Unrecognized compensation cost | $ 3.5 |
Benefit Plans (Defined Benefit
Benefit Plans (Defined Benefit Pension And Other Postretirement Benefits Plans) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | ||
Defined benefit pension plans [Member] | |||||
Defined Benefit Plan Disclosure [Line Items] | |||||
Service cost | $ 3.1 | $ 3.2 | $ 9.3 | $ 9.5 | |
Interest cost | 12.7 | 13.2 | 38.3 | 39.7 | |
Expected return on plan assets | (16.3) | (16.3) | (49.1) | (49.1) | |
Amortization of prior service cost (credit) | (0.1) | (0.1) | (0.3) | (0.2) | |
Amortization of actuarial loss | 9.4 | 9.3 | 28.2 | 28 | |
Settlement losses | [1] | 0.9 | 0 | 0.9 | 0 |
Total | 9.7 | 9.3 | 27.3 | 27.9 | |
OPEB Plans [Member] | |||||
Defined Benefit Plan Disclosure [Line Items] | |||||
Service cost | 1.2 | 1.4 | 3.7 | 4 | |
Interest cost | 2.2 | 2.3 | 6.5 | 7 | |
Expected return on plan assets | (1.5) | (1.6) | (4.6) | (4.6) | |
Amortization of prior service cost (credit) | (0.1) | (1) | (0.2) | (3.1) | |
Amortization of actuarial loss | 1 | 1.2 | 2.9 | 3.6 | |
Settlement losses | [1] | 0 | 0 | 0 | 0 |
Total | 2.8 | 2.3 | 8.3 | 6.9 | |
IPL [Member] | Defined benefit pension plans [Member] | |||||
Defined Benefit Plan Disclosure [Line Items] | |||||
Service cost | 1.8 | 1.8 | 5.5 | 5.6 | |
Interest cost | 5.9 | 6.1 | 17.6 | 18.4 | |
Expected return on plan assets | (7.7) | (7.7) | (23.1) | (23.2) | |
Amortization of prior service cost (credit) | 0 | 0 | (0.1) | (0.1) | |
Amortization of actuarial loss | 4 | 4.2 | 12.1 | 12.4 | |
Total | 4 | 4.4 | 12 | 13.1 | |
IPL [Member] | OPEB Plans [Member] | |||||
Defined Benefit Plan Disclosure [Line Items] | |||||
Service cost | 0.5 | 0.5 | 1.6 | 1.7 | |
Interest cost | 0.8 | 1 | 2.6 | 2.9 | |
Expected return on plan assets | (1) | (1) | (3.2) | (3.2) | |
Amortization of prior service cost (credit) | 0 | (0.7) | 0 | (2) | |
Amortization of actuarial loss | 0.5 | 0.7 | 1.5 | 2 | |
Total | 0.8 | 0.5 | 2.5 | 1.4 | |
WPL [Member] | Defined benefit pension plans [Member] | |||||
Defined Benefit Plan Disclosure [Line Items] | |||||
Service cost | 1.2 | 1.3 | 3.6 | 3.7 | |
Interest cost | 5.5 | 5.5 | 16.4 | 16.7 | |
Expected return on plan assets | (7.2) | (7) | (21.4) | (21.2) | |
Amortization of prior service cost (credit) | 0.1 | 0 | 0.1 | 0.1 | |
Amortization of actuarial loss | 4.6 | 4.4 | 13.9 | 13.2 | |
Total | 4.2 | 4.2 | 12.6 | 12.5 | |
WPL [Member] | OPEB Plans [Member] | |||||
Defined Benefit Plan Disclosure [Line Items] | |||||
Service cost | 0.5 | 0.5 | 1.4 | 1.5 | |
Interest cost | 0.9 | 0.9 | 2.6 | 2.8 | |
Expected return on plan assets | (0.2) | (0.2) | (0.6) | (0.6) | |
Amortization of prior service cost (credit) | (0.1) | (0.3) | (0.2) | (0.7) | |
Amortization of actuarial loss | 0.4 | 0.5 | 1.2 | 1.4 | |
Total | $ 1.5 | $ 1.4 | $ 4.4 | $ 4.4 | |
[1] | Settlement losses related to payments made to retired executives of Alliant Energy. |
Benefit Plans (Recognized Compe
Benefit Plans (Recognized Compensation Expense And Income Tax Benefits) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Compensation expense | $ 5.1 | $ 4.4 | $ 9.9 | $ 16.8 |
Income tax benefits | 2.1 | 1.7 | 4 | 6.8 |
IPL [Member] | ||||
Compensation expense | 2.8 | 2.4 | 5.4 | 8.9 |
Income tax benefits | 1.1 | 1 | 2.2 | 3.7 |
WPL [Member] | ||||
Compensation expense | 2.1 | 1.9 | 4.1 | 7.3 |
Income tax benefits | $ 0.9 | $ 0.7 | $ 1.7 | $ 2.9 |
Benefit Plans (Summary Of Perfo
Benefit Plans (Summary Of Performance Shares and Performance Units Activity) (Details) $ in Millions | 9 Months Ended |
Sep. 30, 2017USD ($)shares | |
Performance Shares [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] | |
Nonvested, January 1 (in shares/awards) | 257,599 |
Granted (in shares/awards) | 65,350 |
Vested (in shares/awards) | (99,438) |
Forfeited (in shares/awards) | 0 |
Nonvested, September 30 (in shares/awards) | 223,511 |
Performance Units [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] | |
Nonvested, January 1 (in shares/awards) | 93,320 |
Granted (in shares/awards) | 21,558 |
Vested (in shares/awards) | (37,395) |
Forfeited (in shares/awards) | (4,243) |
Nonvested, September 30 (in shares/awards) | 73,240 |
2014 Grant [Member] | Performance Shares [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] | |
Vested (in shares/awards) | (99,438) |
Vested percentage of the target | 147.50% |
Aggregate payout value | $ | $ 5.6 |
Payout - cash | $ | $ 5.1 |
Payout - common stock shares issued (in shares) | 5,185 |
2014 Grant [Member] | Performance Units [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] | |
Vested (in shares/awards) | (37,395) |
Vested percentage of the target | 147.50% |
Aggregate payout value | $ | $ 1.5 |
Payout - cash | $ | $ 1.5 |
Benefit Plans (Fair Values Of N
Benefit Plans (Fair Values Of Nonvested Performance Shares And Performance Units) (Details) - $ / shares | 9 Months Ended | |
Sep. 30, 2017 | Dec. 31, 2016 | |
Performance Shares [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 223,511 | 257,599 |
Performance Units [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 73,240 | 93,320 |
2017 Grant [Member] | Performance Shares [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 65,350 | |
Alliant Energy common stock closing price on September 29, 2017 (in dollars per share) | $ 41.57 | |
Estimated payout percentage based on performance criteria | 100.00% | |
Fair values of each nonvested award (in dollars per share) | $ 41.57 | |
2017 Grant [Member] | Performance Units [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 19,531 | |
Alliant Energy common stock closing price on September 29, 2017 (in dollars per share) | $ 41.57 | |
Estimated payout percentage based on performance criteria | 100.00% | |
Fair values of each nonvested award (in dollars per share) | $ 41.57 | |
2016 Grant [Member] | Performance Shares [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 67,355 | |
Alliant Energy common stock closing price on September 29, 2017 (in dollars per share) | $ 41.57 | |
Estimated payout percentage based on performance criteria | 138.00% | |
Fair values of each nonvested award (in dollars per share) | $ 57.37 | |
2016 Grant [Member] | Performance Units [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 21,751 | |
Alliant Energy common stock closing price on September 29, 2017 (in dollars per share) | $ 41.57 | |
Estimated payout percentage based on performance criteria | 138.00% | |
Fair values of each nonvested award (in dollars per share) | $ 57.37 | |
2015 Grant [Member] | Performance Shares [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 90,806 | |
Alliant Energy common stock closing price on September 29, 2017 (in dollars per share) | $ 41.57 | |
Estimated payout percentage based on performance criteria | 113.00% | |
Fair values of each nonvested award (in dollars per share) | $ 46.97 | |
2015 Grant [Member] | Performance Units [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Nonvested awards at target (in shares/awards) | 31,958 | |
Alliant Energy common stock closing price on grant date (in dollars per share) | $ 32.55 | |
Estimated payout percentage based on performance criteria | 113.00% | |
Fair values of each nonvested award (in dollars per share) | $ 36.78 |
Benefit Plans (Summary Of Restr
Benefit Plans (Summary Of Restricted Stock and Restricted Stock Units Activity) (Details) | 9 Months Ended |
Sep. 30, 2017$ / sharesshares | |
Performance Restricted Stock Unit [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] | |
Nonvested, January 1 (in shares/awards) | 67,355 |
Nonvested, January 1, weighted average grant date fair value (in dollars per share) | $ / shares | $ 33.96 |
Granted (in shares/awards) | 65,350 |
Granted, weighted average grant date fair value (in dollars per share) | $ / shares | $ 39.12 |
Nonvested, September 30 (in shares/awards) | 132,705 |
Nonvested, September 30, weighted average grant date fair value (in dollars per share) | $ / shares | $ 36.50 |
Restricted Stock Units [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] | |
Nonvested, January 1 (in shares/awards) | 57,736 |
Granted (in shares/awards) | 56,013 |
Nonvested, September 30 (in shares/awards) | 113,749 |
Fair Value Measurements (Narrat
Fair Value Measurements (Narrative) (Details) | 9 Months Ended |
Sep. 30, 2017 | |
IPL [Member] | |
Cumulative preferred stock rate | 5.10% |
Fair Value Measurements (Fair V
Fair Value Measurements (Fair Value Measurements) (Details) - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 |
Assets: | ||
Deferred proceeds | $ 115.3 | $ 211.1 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 4,896.2 | 4,799 |
Cumulative preferred stock of IPL | 202.3 | 194.8 |
IPL [Member] | ||
Assets: | ||
Deferred proceeds | 115.3 | 211.1 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 2,430.1 | 2,352.3 |
Cumulative preferred stock of IPL | 202.3 | 194.8 |
WPL [Member] | ||
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 1,829.3 | 1,807.4 |
Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 29.4 | 41.4 |
Liabilities and Equity: | ||
Derivatives | 45.1 | 28.6 |
Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 21.1 | 20.8 |
Liabilities and Equity: | ||
Derivatives | 18.7 | 8.3 |
Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 8.3 | 20.6 |
Liabilities and Equity: | ||
Derivatives | 26.4 | 20.3 |
Level 1 [Member] | ||
Assets: | ||
Deferred proceeds | 0 | 0 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Cumulative preferred stock of IPL | 202.3 | 194.8 |
Level 1 [Member] | IPL [Member] | ||
Assets: | ||
Deferred proceeds | 0 | 0 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Cumulative preferred stock of IPL | 202.3 | 194.8 |
Level 1 [Member] | WPL [Member] | ||
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Level 1 [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 0 | 0 |
Liabilities and Equity: | ||
Derivatives | 0 | 0 |
Level 1 [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 0 | 0 |
Liabilities and Equity: | ||
Derivatives | 0 | 0 |
Level 1 [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 0 | 0 |
Liabilities and Equity: | ||
Derivatives | 0 | 0 |
Level 2 [Member] | ||
Assets: | ||
Deferred proceeds | 0 | 0 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 4,893.3 | 4,795.7 |
Cumulative preferred stock of IPL | 0 | 0 |
Level 2 [Member] | IPL [Member] | ||
Assets: | ||
Deferred proceeds | 0 | 0 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 2,430.1 | 2,352.3 |
Cumulative preferred stock of IPL | 0 | 0 |
Level 2 [Member] | WPL [Member] | ||
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 1,829.3 | 1,807.4 |
Level 2 [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 2.9 | 4.6 |
Liabilities and Equity: | ||
Derivatives | 14.9 | 0.5 |
Level 2 [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 1.6 | 2.8 |
Liabilities and Equity: | ||
Derivatives | 4.5 | 0.4 |
Level 2 [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 1.3 | 1.8 |
Liabilities and Equity: | ||
Derivatives | 10.4 | 0.1 |
Level 3 [Member] | ||
Assets: | ||
Deferred proceeds | 115.3 | 211.1 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 2.9 | 3.3 |
Cumulative preferred stock of IPL | 0 | 0 |
Level 3 [Member] | IPL [Member] | ||
Assets: | ||
Deferred proceeds | 115.3 | 211.1 |
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Cumulative preferred stock of IPL | 0 | 0 |
Level 3 [Member] | WPL [Member] | ||
Liabilities and Equity: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Level 3 [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 26.5 | 36.8 |
Liabilities and Equity: | ||
Derivatives | 30.2 | 28.1 |
Level 3 [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 19.5 | 18 |
Liabilities and Equity: | ||
Derivatives | 14.2 | 7.9 |
Level 3 [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 7 | 18.8 |
Liabilities and Equity: | ||
Derivatives | 16 | 20.2 |
Carrying Amount [Member] | ||
Assets: | ||
Deferred proceeds | 115.3 | 211.1 |
Liabilities and Equity: | ||
Long-term debt (including current maturities) | 4,360.3 | 4,320.2 |
Cumulative preferred stock of IPL | 200 | 200 |
Carrying Amount [Member] | IPL [Member] | ||
Assets: | ||
Deferred proceeds | 115.3 | 211.1 |
Liabilities and Equity: | ||
Long-term debt (including current maturities) | 2,195 | 2,153.5 |
Cumulative preferred stock of IPL | 200 | 200 |
Carrying Amount [Member] | WPL [Member] | ||
Liabilities and Equity: | ||
Long-term debt (including current maturities) | 1,536.2 | 1,535.2 |
Carrying Amount [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 29.4 | 41.4 |
Liabilities and Equity: | ||
Derivatives | 45.1 | 28.6 |
Carrying Amount [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 21.1 | 20.8 |
Liabilities and Equity: | ||
Derivatives | 18.7 | 8.3 |
Carrying Amount [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 8.3 | 20.6 |
Liabilities and Equity: | ||
Derivatives | $ 26.4 | $ 20.3 |
Fair Value Measurements (Fair62
Fair Value Measurements (Fair Value Measurements Using Significant Unobservable Inputs) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | ||
Commodity Contracts [Member] | |||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | |||||
Beginning balance | $ 9.2 | $ 0.6 | $ 8.7 | $ (32.7) | |
Total net gains (losses) included in changes in net assets (realized/unrealized) | (4.3) | (5.1) | (31.3) | 8 | |
Transfers into Level 3 | 0 | 0.9 | |||
Transfers out of Level 3 | 0 | 0.8 | 12.2 | 1.2 | |
Purchases | 28.3 | 22 | |||
Sales | (0.1) | (0.2) | (0.3) | (0.9) | |
Settlements | (8.5) | (4) | (21.3) | (6.4) | |
Ending balance | (3.7) | (7.9) | (3.7) | (7.9) | |
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized (gains) losses relating to assets and liabilities held at September 30 | (4.2) | (5) | (29.4) | 9.7 | |
Commodity Contracts [Member] | IPL [Member] | |||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | |||||
Beginning balance | 17.1 | 18.3 | 10.1 | (1.9) | |
Total net gains (losses) included in changes in net assets (realized/unrealized) | (4.4) | (0.4) | (13.9) | 4.8 | |
Transfers into Level 3 | 0 | 0.5 | |||
Transfers out of Level 3 | 0 | 0.3 | 3.1 | 0.2 | |
Purchases | 24.6 | 20.6 | |||
Sales | (0.1) | (0.2) | (0.2) | (0.9) | |
Settlements | (7.3) | (4.6) | (18.4) | (9.9) | |
Ending balance | 5.3 | 13.4 | 5.3 | 13.4 | |
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized (gains) losses relating to assets and liabilities held at September 30 | (4.5) | (0.4) | (12.6) | 5.7 | |
Commodity Contracts [Member] | WPL [Member] | |||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | |||||
Beginning balance | (7.9) | (17.7) | (1.4) | (30.8) | |
Total net gains (losses) included in changes in net assets (realized/unrealized) | 0.1 | (4.7) | (17.4) | 3.2 | |
Transfers into Level 3 | 0 | 0.4 | |||
Transfers out of Level 3 | 0 | 0.5 | 9.1 | 1 | |
Purchases | 3.7 | 1.4 | |||
Sales | (0.1) | 0 | |||
Settlements | (1.2) | (0.6) | (2.9) | (3.5) | |
Ending balance | (9) | (21.3) | (9) | (21.3) | |
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized (gains) losses relating to assets and liabilities held at September 30 | 0.3 | (4.6) | (16.8) | 4 | |
Deferred Proceeds [Member] | |||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | |||||
Beginning balance | 170 | 74.4 | 211.1 | 172 | |
Total net gains (losses) included in changes in net assets (realized/unrealized) | 0 | 0 | 0 | 0 | |
Transfers into Level 3 | 0 | 0 | |||
Transfers out of Level 3 | 0 | 0 | 0 | 0 | |
Purchases | 0 | 0 | |||
Sales | 0 | 0 | 0 | 0 | |
Settlements | [1] | (54.7) | 165.3 | (95.8) | 67.7 |
Ending balance | 115.3 | 239.7 | 115.3 | 239.7 | |
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized (gains) losses relating to assets and liabilities held at September 30 | 0 | 0 | 0 | 0 | |
Deferred Proceeds [Member] | IPL [Member] | |||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | |||||
Beginning balance | 170 | 74.4 | 211.1 | 172 | |
Total net gains (losses) included in changes in net assets (realized/unrealized) | 0 | 0 | 0 | 0 | |
Transfers into Level 3 | 0 | 0 | |||
Transfers out of Level 3 | 0 | 0 | 0 | 0 | |
Purchases | 0 | 0 | |||
Sales | 0 | 0 | 0 | 0 | |
Settlements | [1] | (54.7) | 165.3 | (95.8) | 67.7 |
Ending balance | 115.3 | 239.7 | 115.3 | 239.7 | |
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized (gains) losses relating to assets and liabilities held at September 30 | $ 0 | $ 0 | $ 0 | $ 0 | |
[1] | Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold. |
Fair Value Measurements (Fair63
Fair Value Measurements (Fair Value Of Net Derivative Assets (Liabilities)) (Details) - Commodity Contracts [Member] - USD ($) $ in Millions | Sep. 30, 2017 | Jun. 30, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Dec. 31, 2015 |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | $ (3.7) | $ 9.2 | $ 8.7 | $ (7.9) | $ 0.6 | $ (32.7) |
Excluding Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative liabilities | 22.2 | 2.3 | ||||
Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 18.5 | 11 | ||||
IPL [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 5.3 | 17.1 | 10.1 | 13.4 | 18.3 | (1.9) |
IPL [Member] | Excluding Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 0.1 | |||||
Fair value, net derivative liabilities | 10.4 | |||||
IPL [Member] | Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 15.7 | 10 | ||||
WPL [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | (9) | $ (7.9) | (1.4) | $ (21.3) | $ (17.7) | $ (30.8) |
WPL [Member] | Excluding Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative liabilities | 11.8 | 2.4 | ||||
WPL [Member] | Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | $ 2.8 | $ 1 |
Derivative Instruments (Notiona
Derivative Instruments (Notional Amounts Of Derivative Instruments) (Details) - Commodity [Member] gal in Thousands, T in Thousands, MWh in Thousands, Dekatherms in Thousands | 9 Months Ended |
Sep. 30, 2017DekathermsMWhTgal | |
Electricity (MWhs) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | 1,645 |
Electricity (MWhs) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | 0 |
Electricity (MWhs) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | 1,645 |
FTRs (MWhs) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | 14,745 |
FTRs (MWhs) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | 9,219 |
FTRs (MWhs) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | 5,526 |
Natural Gas (Dths) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Dths) | Dekatherms | 173,234 |
Natural Gas (Dths) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Dths) | Dekatherms | 79,561 |
Natural Gas (Dths) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Dths) | Dekatherms | 93,673 |
Coal (Tons) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Tons) | T | 4,963 |
Coal (Tons) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Tons) | T | 1,820 |
Coal (Tons) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Tons) | T | 3,143 |
Diesel Fuel (Gallons) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Gallons) | gal | 7,308 |
Diesel Fuel (Gallons) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Gallons) | gal | 0 |
Diesel Fuel (Gallons) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Gallons) | gal | 7,308 |
Derivative Instruments (Fair Va
Derivative Instruments (Fair Value Of Financial Instruments) (Details) - Commodity Contracts [Member] - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 |
Derivatives, Fair Value [Line Items] | ||
Current derivative assets | $ 26.7 | $ 29.4 |
Non-current derivative assets | 2.7 | 12 |
Current derivative liabilities | 18.5 | 13.3 |
Non-current derivative liabilities | 26.6 | 15.3 |
IPL [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Current derivative assets | 20.3 | 19.1 |
Non-current derivative assets | 0.8 | 1.7 |
Current derivative liabilities | 4.6 | 2.7 |
Non-current derivative liabilities | 14.1 | 5.6 |
WPL [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Current derivative assets | 6.4 | 10.3 |
Non-current derivative assets | 1.9 | 10.3 |
Current derivative liabilities | 13.9 | 10.6 |
Non-current derivative liabilities | $ 12.5 | $ 9.7 |
Commitments And Contingencies66
Commitments And Contingencies (Narrative) (Details) $ in Millions | 9 Months Ended | |
Sep. 30, 2017USD ($) | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | $ 2,303 | |
Present value abandonment obligation | 33 | |
IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 1,707 | |
Indemnification obligations, maximum | 17 | |
WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 588 | |
Capital Purchase Obligation [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 105 | |
Capital Purchase Obligation [Member] | IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 8 | |
Capital Purchase Obligation [Member] | WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 97 | |
Purchased Power [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 1,278 | [1] |
Purchased Power [Member] | IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 1,194 | [1] |
Purchased Power [Member] | WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 84 | [1] |
Environmental Issue [Member] | IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Environmental mitigation projects to be completed, value | 6 | |
Environmental Issue [Member] | WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Environmental mitigation projects to be completed, value | 7 | |
Indemnification Agreement [Member] | ||
Commitments and Contingencies [Line Items] | ||
Indemnification obligations, maximum | 98 | |
Indemnification Agreement [Member] | Purchased Power [Member] | ||
Commitments and Contingencies [Line Items] | ||
Indemnification obligations, maximum | $ 17 | |
[1] | Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. |
Commitments And Contingencies67
Commitments And Contingencies (Other Purchase Obligations) (Details) $ in Millions | 9 Months Ended | |
Sep. 30, 2017USD ($) | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | $ 2,303 | |
Individual commitments incurred | 1 | |
IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 1,707 | |
Individual commitments incurred | 1 | |
WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 588 | |
Individual commitments incurred | 1 | |
Purchased Power [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 1,278 | [1] |
Purchased Power [Member] | IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 1,194 | [1] |
Purchased Power [Member] | WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 84 | [1] |
Natural gas [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 847 | |
Natural gas [Member] | IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 422 | |
Natural gas [Member] | WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 425 | |
Coal [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 144 | [2] |
Coal [Member] | IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 66 | [2] |
Coal [Member] | WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 78 | [2] |
Other [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 34 | [3] |
Other [Member] | IPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | 25 | [3] |
Other [Member] | WPL [Member] | ||
Commitments and Contingencies [Line Items] | ||
Minimum future commitments | $ 1 | [3] |
[1] | Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased. | |
[2] | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change. | |
[3] | Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017. |
Commitments And Contingencies68
Commitments And Contingencies (MPG Site Estimated Future Costs And Recorded Liabilities) (Details) - Manufactured Gas Plant Sites [Member] $ in Millions | 9 Months Ended |
Sep. 30, 2017USD ($) | |
Commitments and Contingencies [Line Items] | |
Minimum range of estimated future costs | $ 12 |
Maximum range of estimated future costs | 31 |
Current and non-current environmental liabilities | 16 |
IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum range of estimated future costs | 10 |
Maximum range of estimated future costs | 27 |
Current and non-current environmental liabilities | $ 14 |
Segments Of Business (Schedule
Segments Of Business (Schedule Of Segments Of Business) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | ||
Segment Reporting Information [Line Items] | |||||
Operating revenues | $ 906.9 | $ 924.6 | $ 2,526.1 | $ 2,523 | |
Operating income (loss) | 231.5 | 162.6 | 523.7 | 437.1 | |
Income (loss) from continuing operations, net of tax | 168.8 | 128.8 | 362.1 | 310.8 | |
Income (loss) from discontinued operations, net of tax | 0 | (0.4) | 1.4 | (2) | |
Net income (loss) attributable to common shareowners | 168.8 | 128.4 | 363.5 | 308.8 | |
IPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 527.4 | 516.2 | 1,398.1 | 1,385.9 | |
Operating income (loss) | 131.8 | 125.9 | 247.7 | 235.9 | |
Net income (loss) attributable to common shareowners | 120.4 | 114.1 | 200.4 | 191.6 | |
WPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 370.2 | 397 | 1,098.1 | 1,106.9 | |
Operating income (loss) | 90.7 | 115 | 250.4 | 268.8 | |
Net income (loss) attributable to common shareowners | 49.8 | 69 | 133.4 | 158.7 | |
Electric [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | [1] | 840.6 | 864.3 | 2,199.1 | 2,209.1 |
Operating income (loss) | [1] | 232.6 | 244.2 | 475.4 | 473.3 |
Electric [Member] | IPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 489 | 483.2 | 1,217.6 | 1,209.2 | |
Operating income (loss) | 138.3 | 125.9 | 234.5 | 213.8 | |
Electric [Member] | WPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 351.6 | 381.1 | 981.5 | 999.9 | |
Operating income (loss) | 94.3 | 118.3 | 240.9 | 259.5 | |
Gas [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | [1] | 45.8 | 39.5 | 262.7 | 248.7 |
Operating income (loss) | [1] | (2.4) | (3.7) | 29.5 | 27 |
Gas [Member] | IPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 27.4 | 23.9 | 147.2 | 142.6 | |
Operating income (loss) | (2.1) | (1.4) | 14.7 | 15.3 | |
Gas [Member] | WPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 18.4 | 15.6 | 115.5 | 106.1 | |
Operating income (loss) | (0.3) | (2.3) | 14.8 | 11.7 | |
Other Utility [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | [1] | 11.2 | 9.4 | 34.4 | 35 |
Operating income (loss) | [1] | (7.7) | 0.4 | (6.8) | 4.4 |
Other Utility [Member] | IPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 11 | 9.1 | 33.3 | 34.1 | |
Operating income (loss) | (4.4) | 1.4 | (1.5) | 6.8 | |
Other Utility [Member] | WPL [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 0.2 | 0.3 | 1.1 | 0.9 | |
Operating income (loss) | (3.3) | (1) | (5.3) | (2.4) | |
Utility Business [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | [1] | 897.6 | 913.2 | 2,496.2 | 2,492.8 |
Operating income (loss) | [1] | 222.5 | 240.9 | 498.1 | 504.7 |
Income (loss) from continuing operations, net of tax | [1] | 183.1 | 353.5 | 350.3 | |
Income (loss) from discontinued operations, net of tax | [1] | 0 | 0 | 0 | |
Net income (loss) attributable to common shareowners | [1] | 176.3 | 183.1 | 353.5 | 350.3 |
Non-Regulated [Member] | Other Segments [Member] | |||||
Segment Reporting Information [Line Items] | |||||
Operating revenues | 9.3 | 11.4 | 29.9 | 30.2 | |
Operating income (loss) | 9 | (78.3) | 25.6 | (67.6) | |
Income (loss) from continuing operations, net of tax | (54.3) | 8.6 | (39.5) | ||
Income (loss) from discontinued operations, net of tax | (0.4) | 1.4 | (2) | ||
Net income (loss) attributable to common shareowners | $ (7.5) | $ (54.7) | $ 10 | $ (41.5) | |
[1] | Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. |
Related Parties (Narrative) (De
Related Parties (Narrative) (Details) - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 |
ATC LLC [Member] | WPL Owed ATC LLC [Member] | Equity Method Investee [Member] | ||
Related Party Transactions [Line Items] | ||
Net amounts owed | $ 8 | $ 8 |
Related Parties (Service Agreem
Related Parties (Service Agreements) (Details) - Corporate Services [Member] - Subsidiary of Common Parent [Member] - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
Administrative and General Services Billings [Member] | IPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 48 | $ 41 | $ 130 | $ 124 |
Administrative and General Services Billings [Member] | WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 37 | 33 | 100 | 103 |
Sales Credited [Member] | IPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 8 | 4 | 15 | 7 |
Sales Credited [Member] | WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 6 | 3 | 8 | 6 |
Purchases Billed [Member] | IPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 109 | 126 | 271 | 324 |
Purchases Billed [Member] | WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 32 | $ 23 | $ 99 | $ 65 |
Related Parties (Net Intercompa
Related Parties (Net Intercompany Payables) (Details) - Subsidiary of Common Parent [Member] - Corporate Services [Member] - USD ($) $ in Millions | Sep. 30, 2017 | Dec. 31, 2016 |
IPL [Member] | ||
Related Party Transactions [Line Items] | ||
Net amounts owed | $ 118 | $ 104 |
WPL [Member] | ||
Related Party Transactions [Line Items] | ||
Net amounts owed | $ 64 | $ 72 |
Related Parties (Amounts Billed
Related Parties (Amounts Billed Between Parties) (Details) - ATC LLC [Member] - Equity Method Investee [Member] - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
ATC LLC Billings To WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 26 | $ 28 | $ 79 | $ 82 |
WPL Billings To ATC LLC [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 2 | $ 4 | $ 8 | $ 10 |