Document And Entity Information
Document And Entity Information | 9 Months Ended |
Sep. 30, 2021shares | |
Entity Information [Line Items] | |
Document Type | 10-Q |
Document Quarterly Report | true |
Document Period End Date | Sep. 30, 2021 |
Document Transition Report | false |
Entity Registrant Name | ALLIANT ENERGY CORP |
Entity Central Index Key | 0000352541 |
Entity Incorporation, State or Country Code | WI |
Entity Address, Address Line One | 4902 N. Biltmore Lane |
Entity Address, City or Town | Madison |
Entity Address, State or Province | WI |
Entity Address, Postal Zip Code | 53718 |
City Area Code | 608 |
Local Phone Number | 458-3311 |
Entity File Number | 1-9894 |
Entity Tax Identification Number | 39-1380265 |
Title of 12(b) Security | Common Stock, $0.01 Par Value |
Trading Symbol | LNT |
Security Exchange Name | NASDAQ |
Entity Current Reporting Status | Yes |
Entity Interactive Data Current | Yes |
Entity Filer Category | Large Accelerated Filer |
Entity Small Business | false |
Entity Emerging Growth Company | false |
Entity Shell Company | false |
Entity Common Stock, Shares Outstanding | 250,360,787 |
Current Fiscal Year End Date | --12-31 |
Document Fiscal Year Focus | 2021 |
Document Fiscal Period Focus | Q3 |
Amendment Flag | false |
IPL [Member] | |
Entity Information [Line Items] | |
Entity Registrant Name | INTERSTATE POWER & LIGHT CO |
Entity Central Index Key | 0000052485 |
Entity Incorporation, State or Country Code | IA |
Entity Address, Address Line One | Alliant Energy Tower |
Entity Address, City or Town | Cedar Rapids |
Entity Address, State or Province | IA |
Entity Address, Postal Zip Code | 52401 |
City Area Code | 319 |
Local Phone Number | 786-4411 |
Entity File Number | 1-4117 |
Entity Tax Identification Number | 42-0331370 |
Title of 12(b) Security | 5.100% Series D Cumulative Perpetual Preferred Stock, $0.01 Par Value |
Trading Symbol | IPLDP |
Security Exchange Name | NASDAQ |
Entity Current Reporting Status | Yes |
Entity Interactive Data Current | Yes |
Entity Filer Category | Non-accelerated Filer |
Entity Small Business | false |
Entity Emerging Growth Company | false |
Entity Shell Company | false |
Entity Common Stock, Shares Outstanding | 13,370,788 |
WPL [Member] | |
Entity Information [Line Items] | |
Entity Registrant Name | WISCONSIN POWER & LIGHT CO |
Entity Central Index Key | 0000107832 |
Entity Incorporation, State or Country Code | WI |
Entity Address, Address Line One | 4902 N. Biltmore Lane |
Entity Address, City or Town | Madison |
Entity Address, State or Province | WI |
Entity Address, Postal Zip Code | 53718 |
City Area Code | 608 |
Local Phone Number | 458-3311 |
Entity File Number | 0-337 |
Entity Tax Identification Number | 39-0714890 |
Entity Current Reporting Status | Yes |
Entity Interactive Data Current | Yes |
Entity Filer Category | Non-accelerated Filer |
Entity Small Business | false |
Entity Emerging Growth Company | false |
Entity Shell Company | false |
Entity Common Stock, Shares Outstanding | 13,236,601 |
Condensed Consolidated Statemen
Condensed Consolidated Statements Of Income - USD ($) shares in Millions, $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Revenues: | ||||
Electric utility | $ 939 | $ 852 | $ 2,357 | $ 2,257 |
Gas utility | 50 | 42 | 289 | 253 |
Other utility | 13 | 10 | 36 | 32 |
Non-utility | 22 | 16 | 60 | 57 |
Total revenues | 1,024 | 920 | 2,742 | 2,599 |
Operating expenses: | ||||
Electric production fuel and purchased power | 207 | 179 | 478 | 527 |
Electric transmission service | 148 | 132 | 403 | 326 |
Cost of gas sold | 18 | 11 | 149 | 117 |
Other operation and maintenance | 171 | 143 | 477 | 465 |
Depreciation and amortization | 165 | 156 | 494 | 454 |
Taxes other than income taxes | 26 | 27 | 78 | 82 |
Total operating expenses | 735 | 648 | 2,079 | 1,971 |
Operating income | 289 | 272 | 663 | 628 |
Other (income) and deductions: | ||||
Interest expense | 68 | 68 | 206 | 207 |
Equity income from unconsolidated investments, net | (13) | (15) | (47) | (46) |
Allowance for funds used during construction | (7) | (13) | (16) | (51) |
Other | 3 | 3 | 7 | 7 |
Total other (income) and deductions | 51 | 43 | 150 | 117 |
Income before income taxes | 238 | 229 | 513 | 511 |
Income tax benefit | (21) | (20) | (66) | (47) |
Net income | 259 | 249 | 579 | 558 |
Preferred dividend requirements of Interstate Power and Light Company | 3 | 3 | 8 | 8 |
Net income attributable to common shareowners | $ 256 | $ 246 | $ 571 | $ 550 |
Weighted average number of common shares outstanding: | ||||
Basic (in shares) | 250.3 | 249.7 | 250.2 | 247.9 |
Diluted (in shares) | 250.8 | 250 | 250.6 | 248.1 |
Earnings per weighted average common share attributable to Alliant Energy common shareowners: | ||||
Basic (in dollars per share) | $ 1.02 | $ 0.99 | $ 2.28 | $ 2.22 |
Diluted (in dollars per share) | $ 1.02 | $ 0.98 | $ 2.28 | $ 2.22 |
IPL [Member] | ||||
Revenues: | ||||
Electric utility | $ 555 | $ 519 | $ 1,343 | $ 1,332 |
Gas utility | 31 | 24 | 165 | 141 |
Other utility | 13 | 10 | 35 | 31 |
Total revenues | 599 | 553 | 1,543 | 1,504 |
Operating expenses: | ||||
Electric production fuel and purchased power | 101 | 102 | 215 | 304 |
Electric transmission service | 103 | 93 | 274 | 212 |
Cost of gas sold | 12 | 6 | 84 | 63 |
Other operation and maintenance | 95 | 85 | 253 | 269 |
Depreciation and amortization | 94 | 89 | 281 | 264 |
Taxes other than income taxes | 14 | 16 | 42 | 45 |
Total operating expenses | 419 | 391 | 1,149 | 1,157 |
Operating income | 180 | 162 | 394 | 347 |
Other (income) and deductions: | ||||
Interest expense | 34 | 35 | 103 | 104 |
Allowance for funds used during construction | (2) | (6) | (7) | (21) |
Other | 0 | 1 | 2 | 3 |
Total other (income) and deductions | 32 | 30 | 98 | 86 |
Income before income taxes | 148 | 132 | 296 | 261 |
Income tax benefit | (12) | (19) | (34) | (37) |
Net income | 160 | 151 | 330 | 298 |
Preferred dividend requirements of Interstate Power and Light Company | 3 | 3 | 8 | 8 |
Net income attributable to common shareowners | 157 | 148 | 322 | 290 |
WPL [Member] | ||||
Revenues: | ||||
Electric utility | 384 | 333 | 1,014 | 925 |
Gas utility | 19 | 18 | 124 | 112 |
Other utility | 0 | 0 | 1 | 1 |
Total revenues | 403 | 351 | 1,139 | 1,038 |
Operating expenses: | ||||
Electric production fuel and purchased power | 105 | 78 | 263 | 223 |
Electric transmission service | 44 | 39 | 128 | 114 |
Cost of gas sold | 6 | 4 | 65 | 53 |
Other operation and maintenance | 66 | 65 | 194 | 172 |
Depreciation and amortization | 70 | 65 | 209 | 186 |
Taxes other than income taxes | 12 | 11 | 35 | 35 |
Total operating expenses | 303 | 262 | 894 | 783 |
Operating income | 100 | 89 | 245 | 255 |
Other (income) and deductions: | ||||
Interest expense | 25 | 26 | 77 | 78 |
Allowance for funds used during construction | (5) | (6) | (9) | (29) |
Other | 2 | 1 | 3 | 3 |
Total other (income) and deductions | 22 | 21 | 71 | 52 |
Income before income taxes | 78 | 68 | 174 | 203 |
Income tax benefit | (15) | (5) | (41) | (17) |
Net income | $ 93 | $ 73 | $ 215 | $ 220 |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
Current assets: | ||
Cash and cash equivalents | $ 20 | $ 54 |
Accounts receivable, less allowance for expected credit losses | 392 | 412 |
Production fuel, at weighted average cost | 42 | 66 |
Gas stored underground, at weighted average cost | 58 | 46 |
Materials and supplies, at weighted average cost | 118 | 105 |
Regulatory assets | 111 | 81 |
Other | 274 | 123 |
Total current assets | 1,015 | 887 |
Property, plant and equipment, net | 14,738 | 14,336 |
Investments: | ||
ATC Holdings | 338 | 331 |
Other | 176 | 154 |
Total investments | 514 | 485 |
Other assets: | ||
Regulatory assets | 1,907 | 1,929 |
Deferred charges and other | 155 | 73 |
Total other assets | 2,062 | 2,002 |
Total assets | 18,329 | 17,710 |
Current liabilities: | ||
Current maturities of long-term debt | 383 | 8 |
Commercial paper | 316 | 389 |
Accounts payable | 361 | 377 |
Regulatory liabilities | 231 | 249 |
Other | 266 | 274 |
Total current liabilities | 1,557 | 1,297 |
Long-term debt, net (excluding current portion) | 6,692 | 6,769 |
Other liabilities: | ||
Deferred tax liabilities | 1,906 | 1,814 |
Regulatory liabilities | 1,130 | 1,057 |
Pension and other benefit obligations | 452 | 511 |
Other | 407 | 374 |
Total other liabilities | 3,895 | 3,756 |
Commitments and contingencies (Note 14) | ||
Common equity: | ||
Common stock | 3 | 2 |
Additional paid-in capital | 2,733 | 2,704 |
Retained earnings | 3,261 | 2,994 |
Accumulated other comprehensive loss | (1) | (1) |
Shares in deferred compensation trust - 377,875 and 380,542 shares at a weighted average cost of $30.14 and $28.73 per share | (11) | (11) |
Total common equity | 5,985 | 5,688 |
Cumulative preferred stock of Interstate Power and Light Company | 200 | 200 |
Total equity | 6,185 | 5,888 |
Total liabilities and equity | 18,329 | 17,710 |
IPL [Member] | ||
Current assets: | ||
Cash and cash equivalents | 13 | 50 |
Accounts receivable, less allowance for expected credit losses | 205 | 210 |
Production fuel, at weighted average cost | 32 | 48 |
Gas stored underground, at weighted average cost | 33 | 20 |
Materials and supplies, at weighted average cost | 71 | 63 |
Regulatory assets | 86 | 52 |
Other | 108 | 53 |
Total current assets | 548 | 496 |
Property, plant and equipment, net | 7,931 | 7,889 |
Other assets: | ||
Regulatory assets | 1,421 | 1,431 |
Deferred charges and other | 78 | 33 |
Total other assets | 1,499 | 1,464 |
Total assets | 9,978 | 9,849 |
Current liabilities: | ||
Accounts payable | 140 | 162 |
Regulatory liabilities | 104 | 103 |
Other | 171 | 182 |
Total current liabilities | 415 | 447 |
Long-term debt, net (excluding current portion) | 3,347 | 3,345 |
Other liabilities: | ||
Deferred tax liabilities | 1,079 | 1,035 |
Regulatory liabilities | 616 | 573 |
Pension and other benefit obligations | 161 | 186 |
Other | 325 | 299 |
Total other liabilities | 2,181 | 2,093 |
Commitments and contingencies (Note 14) | ||
Common equity: | ||
Common stock | 33 | 33 |
Additional paid-in capital | 2,802 | 2,752 |
Retained earnings | 1,000 | 979 |
Total common equity | 3,835 | 3,764 |
Cumulative preferred stock of Interstate Power and Light Company | 200 | 200 |
Total equity | 4,035 | 3,964 |
Total liabilities and equity | 9,978 | 9,849 |
WPL [Member] | ||
Current assets: | ||
Cash and cash equivalents | 4 | 3 |
Accounts receivable, less allowance for expected credit losses | 175 | 192 |
Production fuel, at weighted average cost | 10 | 18 |
Gas stored underground, at weighted average cost | 25 | 26 |
Materials and supplies, at weighted average cost | 45 | 40 |
Regulatory assets | 25 | 29 |
Prepaid gross receipts tax | 29 | 42 |
Other | 99 | 12 |
Total current assets | 412 | 362 |
Property, plant and equipment, net | 6,367 | 6,022 |
Other assets: | ||
Regulatory assets | 486 | 498 |
Deferred charges and other | 76 | 30 |
Total other assets | 562 | 528 |
Total assets | 7,341 | 6,912 |
Current liabilities: | ||
Commercial paper | 3 | 257 |
Accounts payable | 160 | 154 |
Regulatory liabilities | 127 | 146 |
Other | 116 | 117 |
Total current liabilities | 406 | 674 |
Long-term debt, net (excluding current portion) | 2,429 | 2,130 |
Other liabilities: | ||
Deferred tax liabilities | 747 | 702 |
Regulatory liabilities | 514 | 484 |
Finance lease obligations - Sheboygan Falls Energy Facility | 34 | 42 |
Pension and other benefit obligations | 193 | 222 |
Other | 206 | 180 |
Total other liabilities | 1,694 | 1,630 |
Commitments and contingencies (Note 14) | ||
Common equity: | ||
Common stock | 66 | 66 |
Additional paid-in capital | 1,704 | 1,459 |
Retained earnings | 1,042 | 953 |
Total common equity | 2,812 | 2,478 |
Total equity | 2,812 | 2,478 |
Total liabilities and equity | $ 7,341 | $ 6,912 |
Condensed Consolidated Balanc_2
Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2021 | Dec. 31, 2020 |
Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
Common stock, shares authorized (in shares) | 480,000,000 | 480,000,000 |
Common stock, shares outstanding (in shares) | 250,360,787 | 249,868,415 |
Shares in deferred compensation trust (in shares) | 377,875 | 380,542 |
Shares in deferred compensation trust, weighted average cost per share (in dollars per share) | $ 30.14 | $ 28.73 |
IPL [Member] | ||
Common stock, par value (in dollars per share) | $ 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 (in dollars per share) | $ 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 Statem_2
Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions | 9 Months Ended | |
Sep. 30, 2021 | Sep. 30, 2020 | |
Cash flows from operating activities: | ||
Net income | $ 579 | $ 558 |
Adjustments to reconcile net income to net cash flows from operating activities: | ||
Depreciation and amortization | 494 | 454 |
Deferred tax benefit and tax credits | (69) | (48) |
Other | 7 | (17) |
Other changes in assets and liabilities: | ||
Accounts receivable | (397) | (316) |
Derivative assets | (202) | (22) |
Regulatory liabilities | 25 | (72) |
Deferred income taxes | 160 | 143 |
Pension and other benefit obligations | (59) | (61) |
DAEC PPA amendment buyout payment | 0 | (110) |
Other | (61) | (73) |
Net cash flows from operating activities | 477 | 436 |
Cash flows from (used for) investing activities: | ||
Utility business construction and acquisition expenditures | (772) | (935) |
Other construction and acquisition expenditures | (60) | (39) |
Cash receipts on sold receivables | 423 | 318 |
Other | (43) | (23) |
Net cash flows from (used for) investing activities | (452) | (679) |
Cash flows from (used for) financing activities: | ||
Common stock dividends | (304) | (281) |
Proceeds from issuance of common stock, net | 22 | 241 |
Proceeds from issuance of long-term debt | 300 | 1,050 |
Payments to retire long-term debt | (4) | (654) |
Net change in commercial paper | (73) | 85 |
Other | 2 | (22) |
Net cash flows from (used for) financing activities | (57) | 419 |
Net increase (decrease) in cash, cash equivalents and restricted cash | (32) | 176 |
Cash, cash equivalents and restricted cash at beginning of period | 56 | 18 |
Cash, cash equivalents and restricted cash at end of period | 24 | 194 |
Supplemental cash flows information: | ||
Interest | (197) | (197) |
Income taxes, net | (1) | 6 |
Significant non-cash investing and financing activities: | ||
Accrued capital expenditures | 91 | 202 |
Beneficial interest obtained in exchange for securitized accounts receivable | 164 | 201 |
IPL [Member] | ||
Cash flows from operating activities: | ||
Net income | 330 | 298 |
Adjustments to reconcile net income to net cash flows from operating activities: | ||
Depreciation and amortization | 281 | 264 |
Deferred tax benefit and tax credits | (13) | (42) |
Other | (1) | (9) |
Other changes in assets and liabilities: | ||
Accounts receivable | (412) | (337) |
Derivative assets | (86) | (12) |
Regulatory assets | (33) | (32) |
Regulatory liabilities | 30 | (11) |
Deferred income taxes | 56 | 62 |
Pension and other benefit obligations | (25) | (19) |
DAEC PPA amendment buyout payment | 0 | (110) |
Other | (32) | (33) |
Net cash flows from operating activities | 95 | 19 |
Cash flows from (used for) investing activities: | ||
Utility business construction and acquisition expenditures | (285) | (465) |
Cash receipts on sold receivables | 423 | 318 |
Other | (16) | (55) |
Net cash flows from (used for) investing activities | 122 | (202) |
Cash flows from (used for) financing activities: | ||
Common stock dividends | (301) | (177) |
Capital contributions from parent | 50 | 345 |
Proceeds from issuance of long-term debt | 0 | 400 |
Payments to retire long-term debt | 0 | (200) |
Other | (3) | (9) |
Net cash flows from (used for) financing activities | (254) | 359 |
Net increase (decrease) in cash, cash equivalents and restricted cash | (37) | 176 |
Cash, cash equivalents and restricted cash at beginning of period | 50 | 9 |
Cash, cash equivalents and restricted cash at end of period | 13 | 185 |
Supplemental cash flows information: | ||
Interest | (106) | (109) |
Income taxes, net | 28 | (12) |
Significant non-cash investing and financing activities: | ||
Accrued capital expenditures | 30 | 150 |
Beneficial interest obtained in exchange for securitized accounts receivable | 164 | 201 |
WPL [Member] | ||
Cash flows from operating activities: | ||
Net income | 215 | 220 |
Adjustments to reconcile net income to net cash flows from operating activities: | ||
Depreciation and amortization | 209 | 186 |
Deferred tax benefit and tax credits | (63) | (9) |
Other | 12 | (8) |
Other changes in assets and liabilities: | ||
Derivative assets | (116) | (10) |
Regulatory liabilities | (5) | (61) |
Deferred income taxes | 108 | 79 |
Other | (11) | 5 |
Net cash flows from operating activities | 349 | 402 |
Cash flows from (used for) investing activities: | ||
Utility business construction and acquisition expenditures | (487) | (470) |
Other | (23) | 5 |
Net cash flows from (used for) investing activities | (510) | (465) |
Cash flows from (used for) financing activities: | ||
Common stock dividends | (126) | (127) |
Capital contributions from parent | 245 | 25 |
Proceeds from issuance of long-term debt | 300 | 350 |
Payments to retire long-term debt | 0 | (150) |
Net change in commercial paper | (254) | (29) |
Other | (3) | (8) |
Net cash flows from (used for) financing activities | 162 | 61 |
Net increase (decrease) in cash, cash equivalents and restricted cash | 1 | (2) |
Cash, cash equivalents and restricted cash at beginning of period | 3 | 4 |
Cash, cash equivalents and restricted cash at end of period | 4 | 2 |
Supplemental cash flows information: | ||
Interest | (72) | (71) |
Income taxes, net | (24) | 5 |
Significant non-cash investing and financing activities: | ||
Accrued capital expenditures | $ 59 | $ 50 |
Summary Of Significant Accounti
Summary Of Significant Accounting Policies | 9 Months Ended |
Sep. 30, 2021 | |
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 SEC. 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 2020 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, 2021 are not necessarily indicative of results that may be expected for the year ending December 31, 2021. 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. NOTE 1(b) Asset Impairments - Property, Plant and Equipment of Regulated Operations - In the second quarter of 2021, WPL received approval from MISO to retire Columbia Units 1 and 2, which had a net book value of approximately $470 million in aggregate as of September 30, 2021, and currently anticipates retiring Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024. Alliant Energy and WPL concluded that Columbia Units 1 and 2 met the criteria to be considered probable of abandonment as of September 30, 2021. WPL is currently allowed a full recovery of and a full return on these EGUs from both its retail and wholesale customers, and as a result, Alliant Energy and WPL concluded that no disallowance was required as of September 30, 2021. |
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 SEC. 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 2020 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, 2021 are not necessarily indicative of results that may be expected for the year ending December 31, 2021. 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. NOTE 1(b) Asset Impairments - Property, Plant and Equipment of Regulated Operations - In the second quarter of 2021, WPL received approval from MISO to retire Columbia Units 1 and 2, which had a net book value of approximately $470 million in aggregate as of September 30, 2021, and currently anticipates retiring Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024. Alliant Energy and WPL concluded that Columbia Units 1 and 2 met the criteria to be considered probable of abandonment as of September 30, 2021. WPL is currently allowed a full recovery of and a full return on these EGUs from both its retail and wholesale customers, and as a result, Alliant Energy and WPL concluded that no disallowance was required as of September 30, 2021. |
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 SEC. 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 2020 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, 2021 are not necessarily indicative of results that may be expected for the year ending December 31, 2021. 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. NOTE 1(b) Asset Impairments - Property, Plant and Equipment of Regulated Operations - In the second quarter of 2021, WPL received approval from MISO to retire Columbia Units 1 and 2, which had a net book value of approximately $470 million in aggregate as of September 30, 2021, and currently anticipates retiring Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024. Alliant Energy and WPL concluded that Columbia Units 1 and 2 met the criteria to be considered probable of abandonment as of September 30, 2021. WPL is currently allowed a full recovery of and a full return on these EGUs from both its retail and wholesale customers, and as a result, Alliant Energy and WPL concluded that no disallowance was required as of September 30, 2021. |
Regulatory Matters
Regulatory Matters | 9 Months Ended |
Sep. 30, 2021 | |
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 $931 $890 $881 $843 $50 $47 Pension and OPEB costs 549 580 276 291 273 289 Asset retirement obligations 124 119 85 81 39 38 Assets retired early 98 113 69 77 29 36 IPL’s DAEC PPA amendment 96 110 96 110 — — WPL’s Western Wisconsin gas distribution expansion investments 53 55 — — 53 55 Commodity cost recovery 32 4 17 1 15 3 Derivatives 4 26 4 13 — 13 Other 131 113 79 67 52 46 $2,018 $2,010 $1,507 $1,483 $511 $527 Commodity cost recovery - In February 2021, portions of the central and southern U.S., including Alliant Energy’s service territories, experienced a prolonged period of very cold temperatures and a series of winter storms. These events created significant volatility and increases in commodity prices caused by higher demand for electricity and natural gas and disruptions in commodity supply, resulting in IPL under-recovering its natural gas costs. In March 2021, IPL received approval from the IUB to spread recovery of these higher natural gas costs from its retail customers through December 2021. As of September 30, 2021, IPL’s cumulative under-collection of natural gas costs was $15 million. The extreme temperatures in February 2021 did not impact WPL’s natural gas costs and IPL’s and WPL’s fuel-related costs to the extent of IPL’s natural gas costs. The cost recovery mechanism for WPL’s retail electric customers is based on forecasts of certain fuel-related costs expected to be incurred during forward-looking test periods and fuel monitoring ranges determined by the PSCW during each retail electric rate proceeding or in a separate fuel cost plan approval proceeding. In 2021, WPL’s actual fuel-related costs fell outside these fuel monitoring ranges, resulting in a $12 million deferral as of September 30, 2021. 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, Tax-related $611 $732 $313 $331 $298 $401 Cost of removal obligations 383 367 252 238 131 129 Derivatives 221 28 104 25 117 3 Electric transmission cost recovery 53 68 29 39 24 29 WPL’s West Riverside liquidated damages 40 38 — — 40 38 Other 53 73 22 43 31 30 $1,361 $1,306 $720 $676 $641 $630 Tax-related - Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities are primarily related to excess deferred tax benefits resulting from the remeasurement of accumulated deferred income taxes caused by Federal Tax Reform. During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities decreased primarily due to returning a portion of these excess deferred tax benefits back to customers. |
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 $931 $890 $881 $843 $50 $47 Pension and OPEB costs 549 580 276 291 273 289 Asset retirement obligations 124 119 85 81 39 38 Assets retired early 98 113 69 77 29 36 IPL’s DAEC PPA amendment 96 110 96 110 — — WPL’s Western Wisconsin gas distribution expansion investments 53 55 — — 53 55 Commodity cost recovery 32 4 17 1 15 3 Derivatives 4 26 4 13 — 13 Other 131 113 79 67 52 46 $2,018 $2,010 $1,507 $1,483 $511 $527 Commodity cost recovery - In February 2021, portions of the central and southern U.S., including Alliant Energy’s service territories, experienced a prolonged period of very cold temperatures and a series of winter storms. These events created significant volatility and increases in commodity prices caused by higher demand for electricity and natural gas and disruptions in commodity supply, resulting in IPL under-recovering its natural gas costs. In March 2021, IPL received approval from the IUB to spread recovery of these higher natural gas costs from its retail customers through December 2021. As of September 30, 2021, IPL’s cumulative under-collection of natural gas costs was $15 million. The extreme temperatures in February 2021 did not impact WPL’s natural gas costs and IPL’s and WPL’s fuel-related costs to the extent of IPL’s natural gas costs. The cost recovery mechanism for WPL’s retail electric customers is based on forecasts of certain fuel-related costs expected to be incurred during forward-looking test periods and fuel monitoring ranges determined by the PSCW during each retail electric rate proceeding or in a separate fuel cost plan approval proceeding. In 2021, WPL’s actual fuel-related costs fell outside these fuel monitoring ranges, resulting in a $12 million deferral as of September 30, 2021. 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, Tax-related $611 $732 $313 $331 $298 $401 Cost of removal obligations 383 367 252 238 131 129 Derivatives 221 28 104 25 117 3 Electric transmission cost recovery 53 68 29 39 24 29 WPL’s West Riverside liquidated damages 40 38 — — 40 38 Other 53 73 22 43 31 30 $1,361 $1,306 $720 $676 $641 $630 Tax-related - Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities are primarily related to excess deferred tax benefits resulting from the remeasurement of accumulated deferred income taxes caused by Federal Tax Reform. During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities decreased primarily due to returning a portion of these excess deferred tax benefits back to customers. |
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 $931 $890 $881 $843 $50 $47 Pension and OPEB costs 549 580 276 291 273 289 Asset retirement obligations 124 119 85 81 39 38 Assets retired early 98 113 69 77 29 36 IPL’s DAEC PPA amendment 96 110 96 110 — — WPL’s Western Wisconsin gas distribution expansion investments 53 55 — — 53 55 Commodity cost recovery 32 4 17 1 15 3 Derivatives 4 26 4 13 — 13 Other 131 113 79 67 52 46 $2,018 $2,010 $1,507 $1,483 $511 $527 Commodity cost recovery - In February 2021, portions of the central and southern U.S., including Alliant Energy’s service territories, experienced a prolonged period of very cold temperatures and a series of winter storms. These events created significant volatility and increases in commodity prices caused by higher demand for electricity and natural gas and disruptions in commodity supply, resulting in IPL under-recovering its natural gas costs. In March 2021, IPL received approval from the IUB to spread recovery of these higher natural gas costs from its retail customers through December 2021. As of September 30, 2021, IPL’s cumulative under-collection of natural gas costs was $15 million. The extreme temperatures in February 2021 did not impact WPL’s natural gas costs and IPL’s and WPL’s fuel-related costs to the extent of IPL’s natural gas costs. The cost recovery mechanism for WPL’s retail electric customers is based on forecasts of certain fuel-related costs expected to be incurred during forward-looking test periods and fuel monitoring ranges determined by the PSCW during each retail electric rate proceeding or in a separate fuel cost plan approval proceeding. In 2021, WPL’s actual fuel-related costs fell outside these fuel monitoring ranges, resulting in a $12 million deferral as of September 30, 2021. 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, Tax-related $611 $732 $313 $331 $298 $401 Cost of removal obligations 383 367 252 238 131 129 Derivatives 221 28 104 25 117 3 Electric transmission cost recovery 53 68 29 39 24 29 WPL’s West Riverside liquidated damages 40 38 — — 40 38 Other 53 73 22 43 31 30 $1,361 $1,306 $720 $676 $641 $630 Tax-related - Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities are primarily related to excess deferred tax benefits resulting from the remeasurement of accumulated deferred income taxes caused by Federal Tax Reform. During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s tax-related regulatory liabilities decreased primarily due to returning a portion of these excess deferred tax benefits back to customers. |
Receivables
Receivables | 9 Months Ended |
Sep. 30, 2021 | |
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. In April 2021, IPL amended and extended through March 2023 the purchase commitment from the third party to which it sells its receivables. Effective April 2021, the limit on cash proceeds is $110 million. As of September 30, 2021, IPL had $60 million of available capacity under its sales of accounts receivable program. 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 2021 2020 2021 2020 Maximum outstanding aggregate cash proceeds $110 $1 $110 $96 Average outstanding aggregate cash proceeds 65 1 52 12 The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2021 December 31, 2020 Customer accounts receivable $145 $114 Unbilled utility revenues 83 92 Receivables sold to third party 228 206 Less: cash proceeds 50 1 Deferred proceeds 178 205 Less: allowance for expected credit losses 14 17 Fair value of deferred proceeds $164 $188 As of September 30, 2021, outstanding receivables past due under the Receivables Agreement were $19 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 2021 2020 2021 2020 Collections $607 $561 $1,589 $1,555 Write-offs, net of recoveries 4 1 7 4 |
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. In April 2021, IPL amended and extended through March 2023 the purchase commitment from the third party to which it sells its receivables. Effective April 2021, the limit on cash proceeds is $110 million. As of September 30, 2021, IPL had $60 million of available capacity under its sales of accounts receivable program. 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 2021 2020 2021 2020 Maximum outstanding aggregate cash proceeds $110 $1 $110 $96 Average outstanding aggregate cash proceeds 65 1 52 12 The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2021 December 31, 2020 Customer accounts receivable $145 $114 Unbilled utility revenues 83 92 Receivables sold to third party 228 206 Less: cash proceeds 50 1 Deferred proceeds 178 205 Less: allowance for expected credit losses 14 17 Fair value of deferred proceeds $164 $188 As of September 30, 2021, outstanding receivables past due under the Receivables Agreement were $19 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 2021 2020 2021 2020 Collections $607 $561 $1,589 $1,555 Write-offs, net of recoveries 4 1 7 4 |
Investments
Investments | 9 Months Ended |
Sep. 30, 2021 | |
Schedule of Equity Method Investments [Line Items] | |
Investments | INVESTMENTS Unconsolidated Equity Investments - Alliant Energy’s 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): Three Months Nine Months 2021 2020 2021 2020 ATC Holdings ($12) ($11) ($34) ($36) Other (1) (4) (13) (10) ($13) ($15) ($47) ($46) |
Common Equity
Common Equity | 9 Months Ended |
Sep. 30, 2021 | |
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, 2021 249,868,415 Shareowner Direct Plan 378,823 Equity-based compensation plans 113,549 Shares outstanding, September 30, 2021 250,360,787 Changes in Shareowners’ Equity - A summary of changes in shareowners’ equity was as follows (in millions): Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $3 $2,722 $3,106 ($1) ($11) $200 $6,019 Net income attributable to Alliant Energy common shareowners 256 256 Common stock dividends ($0.4025 per share) (101) (101) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 5 5 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $2 $2,683 $2,874 ($1) ($10) $200 $5,748 Net income attributable to Alliant Energy common shareowners 246 246 Common stock dividends ($0.38 per share) (94) (94) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 4 (1) 3 Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $2 $2,704 $2,994 ($1) ($11) $200 $5,888 Net income attributable to Alliant Energy common shareowners 571 571 Common stock dividends ($1.2075 per share) (304) (304) Shareowner Direct Plan issuances 1 21 22 Equity-based compensation plans and other 8 8 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $2 $2,446 $2,766 $1 ($10) $200 $5,405 Net income attributable to Alliant Energy common shareowners 550 550 Common stock dividends ($1.14 per share) (281) (281) Equity forward settlements and Shareowner Direct Plan issuances 241 241 Equity-based compensation plans and other 6 (1) 5 Adoption of new accounting standard, net of tax (9) (9) Other comprehensive loss, net of tax (2) (2) Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $33 $2,802 $944 $200 $3,979 Net income available for common stock 157 157 Common stock dividends (101) (101) Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $33 $2,523 $915 $200 $3,671 Net income available for common stock 148 148 Common stock dividends (59) (59) Capital contributions from parent 170 170 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $33 $2,752 $979 $200 $3,964 Net income available for common stock 322 322 Common stock dividends (301) (301) Capital contributions from parent 50 50 Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $33 $2,348 $891 $200 $3,472 Net income available for common stock 290 290 Common stock dividends (177) (177) Capital contributions from parent 345 345 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $66 $1,669 $990 $2,725 Net income 93 93 Common stock dividends (41) (41) Capital contributions from parent 35 35 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $66 $1,459 $927 $2,452 Net income 73 73 Common stock dividends (43) (43) Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $66 $1,459 $953 $2,478 Net income 215 215 Common stock dividends (126) (126) Capital contributions from parent 245 245 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $66 $1,434 $864 $2,364 Net income 220 220 Common stock dividends (127) (127) Capital contributions from parent 25 25 Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 |
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, 2021 249,868,415 Shareowner Direct Plan 378,823 Equity-based compensation plans 113,549 Shares outstanding, September 30, 2021 250,360,787 Changes in Shareowners’ Equity - A summary of changes in shareowners’ equity was as follows (in millions): Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $3 $2,722 $3,106 ($1) ($11) $200 $6,019 Net income attributable to Alliant Energy common shareowners 256 256 Common stock dividends ($0.4025 per share) (101) (101) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 5 5 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $2 $2,683 $2,874 ($1) ($10) $200 $5,748 Net income attributable to Alliant Energy common shareowners 246 246 Common stock dividends ($0.38 per share) (94) (94) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 4 (1) 3 Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $2 $2,704 $2,994 ($1) ($11) $200 $5,888 Net income attributable to Alliant Energy common shareowners 571 571 Common stock dividends ($1.2075 per share) (304) (304) Shareowner Direct Plan issuances 1 21 22 Equity-based compensation plans and other 8 8 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $2 $2,446 $2,766 $1 ($10) $200 $5,405 Net income attributable to Alliant Energy common shareowners 550 550 Common stock dividends ($1.14 per share) (281) (281) Equity forward settlements and Shareowner Direct Plan issuances 241 241 Equity-based compensation plans and other 6 (1) 5 Adoption of new accounting standard, net of tax (9) (9) Other comprehensive loss, net of tax (2) (2) Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $33 $2,802 $944 $200 $3,979 Net income available for common stock 157 157 Common stock dividends (101) (101) Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $33 $2,523 $915 $200 $3,671 Net income available for common stock 148 148 Common stock dividends (59) (59) Capital contributions from parent 170 170 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $33 $2,752 $979 $200 $3,964 Net income available for common stock 322 322 Common stock dividends (301) (301) Capital contributions from parent 50 50 Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $33 $2,348 $891 $200 $3,472 Net income available for common stock 290 290 Common stock dividends (177) (177) Capital contributions from parent 345 345 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $66 $1,669 $990 $2,725 Net income 93 93 Common stock dividends (41) (41) Capital contributions from parent 35 35 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $66 $1,459 $927 $2,452 Net income 73 73 Common stock dividends (43) (43) Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $66 $1,459 $953 $2,478 Net income 215 215 Common stock dividends (126) (126) Capital contributions from parent 245 245 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $66 $1,434 $864 $2,364 Net income 220 220 Common stock dividends (127) (127) Capital contributions from parent 25 25 Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 |
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, 2021 249,868,415 Shareowner Direct Plan 378,823 Equity-based compensation plans 113,549 Shares outstanding, September 30, 2021 250,360,787 Changes in Shareowners’ Equity - A summary of changes in shareowners’ equity was as follows (in millions): Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $3 $2,722 $3,106 ($1) ($11) $200 $6,019 Net income attributable to Alliant Energy common shareowners 256 256 Common stock dividends ($0.4025 per share) (101) (101) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 5 5 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $2 $2,683 $2,874 ($1) ($10) $200 $5,748 Net income attributable to Alliant Energy common shareowners 246 246 Common stock dividends ($0.38 per share) (94) (94) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 4 (1) 3 Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $2 $2,704 $2,994 ($1) ($11) $200 $5,888 Net income attributable to Alliant Energy common shareowners 571 571 Common stock dividends ($1.2075 per share) (304) (304) Shareowner Direct Plan issuances 1 21 22 Equity-based compensation plans and other 8 8 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $2 $2,446 $2,766 $1 ($10) $200 $5,405 Net income attributable to Alliant Energy common shareowners 550 550 Common stock dividends ($1.14 per share) (281) (281) Equity forward settlements and Shareowner Direct Plan issuances 241 241 Equity-based compensation plans and other 6 (1) 5 Adoption of new accounting standard, net of tax (9) (9) Other comprehensive loss, net of tax (2) (2) Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $33 $2,802 $944 $200 $3,979 Net income available for common stock 157 157 Common stock dividends (101) (101) Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $33 $2,523 $915 $200 $3,671 Net income available for common stock 148 148 Common stock dividends (59) (59) Capital contributions from parent 170 170 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $33 $2,752 $979 $200 $3,964 Net income available for common stock 322 322 Common stock dividends (301) (301) Capital contributions from parent 50 50 Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $33 $2,348 $891 $200 $3,472 Net income available for common stock 290 290 Common stock dividends (177) (177) Capital contributions from parent 345 345 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $66 $1,669 $990 $2,725 Net income 93 93 Common stock dividends (41) (41) Capital contributions from parent 35 35 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $66 $1,459 $927 $2,452 Net income 73 73 Common stock dividends (43) (43) Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $66 $1,459 $953 $2,478 Net income 215 215 Common stock dividends (126) (126) Capital contributions from parent 245 245 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $66 $1,434 $864 $2,364 Net income 220 220 Common stock dividends (127) (127) Capital contributions from parent 25 25 Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 |
Preferred Stock
Preferred Stock | 9 Months Ended |
Sep. 30, 2021 | |
Preferred Stock | PREFERRED STOCKIn November 2021, IPL announced it will redeem all 8,000,000 outstanding shares of its 5.1% cumulative preferred stock in December 2021 at par value for approximately $200 million plus accrued and unpaid dividends up to the redemption date. |
IPL [Member] | |
Preferred Stock | PREFERRED STOCKIn November 2021, IPL announced it will redeem all 8,000,000 outstanding shares of its 5.1% cumulative preferred stock in December 2021 at par value for approximately $200 million plus accrued and unpaid dividends up to the redemption date. |
Debt
Debt | 9 Months Ended |
Sep. 30, 2021 | |
Debt [Line Items] | |
Debt | DEBT NOTE 7(a) Short-term Debt - In the third quarter of 2021, Alliant Energy, IPL and WPL reallocated credit facility capacity amounts to $500 million for Alliant Energy at the parent company level, $100 million for IPL and $400 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper, and Alliant Energy’s and WPL’s borrowings under the single credit facility, which currently expires in August 2023, classified as short-term debt was as follows (dollars in millions): September 30, 2021 Alliant Energy IPL WPL Amount outstanding $316 $— $3 Weighted average interest rates 0.2% N/A 0.1% Available credit facility capacity $684 $100 $397 Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Maximum amount outstanding (based on daily outstanding balances) $648 $422 $8 $— $320 $139 Average amount outstanding (based on daily outstanding balances) $560 $252 $— $— $221 $83 Weighted average interest rates 0.2% 0.2% 0.2% N/A 0.1% 0.2% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $648 $463 $19 $8 $320 $212 Average amount outstanding (based on daily outstanding balances) $479 $252 $— $— $196 $86 Weighted average interest rates 0.2% 1.1% 0.2% 0.5% 0.1% 1.2% NOTE 7(b) Long-term Debt - In September 2021, WPL issued $300 million of 1.95% debentures due 2031. The debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be disbursed for the construction and development of WPL’s wind and solar EGUs. |
IPL [Member] | |
Debt [Line Items] | |
Debt | DEBT NOTE 7(a) Short-term Debt - In the third quarter of 2021, Alliant Energy, IPL and WPL reallocated credit facility capacity amounts to $500 million for Alliant Energy at the parent company level, $100 million for IPL and $400 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper, and Alliant Energy’s and WPL’s borrowings under the single credit facility, which currently expires in August 2023, classified as short-term debt was as follows (dollars in millions): September 30, 2021 Alliant Energy IPL WPL Amount outstanding $316 $— $3 Weighted average interest rates 0.2% N/A 0.1% Available credit facility capacity $684 $100 $397 Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Maximum amount outstanding (based on daily outstanding balances) $648 $422 $8 $— $320 $139 Average amount outstanding (based on daily outstanding balances) $560 $252 $— $— $221 $83 Weighted average interest rates 0.2% 0.2% 0.2% N/A 0.1% 0.2% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $648 $463 $19 $8 $320 $212 Average amount outstanding (based on daily outstanding balances) $479 $252 $— $— $196 $86 Weighted average interest rates 0.2% 1.1% 0.2% 0.5% 0.1% 1.2% NOTE 7(b) Long-term Debt - In September 2021, WPL issued $300 million of 1.95% debentures due 2031. The debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be disbursed for the construction and development of WPL’s wind and solar EGUs. |
WPL [Member] | |
Debt [Line Items] | |
Debt | DEBT NOTE 7(a) Short-term Debt - In the third quarter of 2021, Alliant Energy, IPL and WPL reallocated credit facility capacity amounts to $500 million for Alliant Energy at the parent company level, $100 million for IPL and $400 million for WPL, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper, and Alliant Energy’s and WPL’s borrowings under the single credit facility, which currently expires in August 2023, classified as short-term debt was as follows (dollars in millions): September 30, 2021 Alliant Energy IPL WPL Amount outstanding $316 $— $3 Weighted average interest rates 0.2% N/A 0.1% Available credit facility capacity $684 $100 $397 Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Maximum amount outstanding (based on daily outstanding balances) $648 $422 $8 $— $320 $139 Average amount outstanding (based on daily outstanding balances) $560 $252 $— $— $221 $83 Weighted average interest rates 0.2% 0.2% 0.2% N/A 0.1% 0.2% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $648 $463 $19 $8 $320 $212 Average amount outstanding (based on daily outstanding balances) $479 $252 $— $— $196 $86 Weighted average interest rates 0.2% 1.1% 0.2% 0.5% 0.1% 1.2% NOTE 7(b) Long-term Debt - In September 2021, WPL issued $300 million of 1.95% debentures due 2031. The debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be disbursed for the construction and development of WPL’s wind and solar EGUs. |
Revenues
Revenues | 9 Months Ended |
Sep. 30, 2021 | |
Disaggregation of Revenue [Line Items] | |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions): Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $348 $328 $207 $189 $141 $139 Retail - commercial 232 210 160 142 72 68 Retail - industrial 265 241 158 149 107 92 Wholesale 55 47 18 17 37 30 Bulk power and other 39 26 12 22 27 4 Total Electric Utility 939 852 555 519 384 333 Gas Utility: Retail - residential 24 22 14 12 10 10 Retail - commercial 13 10 8 6 5 4 Retail - industrial 3 2 3 1 — 1 Transportation/other 10 8 6 5 4 3 Total Gas Utility 50 42 31 24 19 18 Other Utility: Steam 9 8 9 8 — — Other utility 4 2 4 2 — — Total Other Utility 13 10 13 10 — — Non-Utility and Other: Travero and other 22 16 — — — — Total Non-Utility and Other 22 16 — — — — Total revenues $1,024 $920 $599 $553 $403 $351 Alliant Energy IPL WPL Nine Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $868 $845 $488 $472 $380 $373 Retail - commercial 579 556 385 371 194 185 Retail - industrial 677 648 386 384 291 264 Wholesale 142 127 44 44 98 83 Bulk power and other 91 81 40 61 51 20 Total Electric Utility 2,357 2,257 1,343 1,332 1,014 925 Gas Utility: Retail - residential 162 146 90 79 72 67 Retail - commercial 85 70 47 38 38 32 Retail - industrial 11 8 8 5 3 3 Transportation/other 31 29 20 19 11 10 Total Gas Utility 289 253 165 141 124 112 Other Utility: Steam 27 27 27 27 — — Other utility 9 5 8 4 1 1 Total Other Utility 36 32 35 31 1 1 Non-Utility and Other: Travero and other 60 57 — — — — Total Non-Utility and Other 60 57 — — — — Total revenues $2,742 $2,599 $1,543 $1,504 $1,139 $1,038 |
IPL [Member] | |
Disaggregation of Revenue [Line Items] | |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions): Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $348 $328 $207 $189 $141 $139 Retail - commercial 232 210 160 142 72 68 Retail - industrial 265 241 158 149 107 92 Wholesale 55 47 18 17 37 30 Bulk power and other 39 26 12 22 27 4 Total Electric Utility 939 852 555 519 384 333 Gas Utility: Retail - residential 24 22 14 12 10 10 Retail - commercial 13 10 8 6 5 4 Retail - industrial 3 2 3 1 — 1 Transportation/other 10 8 6 5 4 3 Total Gas Utility 50 42 31 24 19 18 Other Utility: Steam 9 8 9 8 — — Other utility 4 2 4 2 — — Total Other Utility 13 10 13 10 — — Non-Utility and Other: Travero and other 22 16 — — — — Total Non-Utility and Other 22 16 — — — — Total revenues $1,024 $920 $599 $553 $403 $351 Alliant Energy IPL WPL Nine Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $868 $845 $488 $472 $380 $373 Retail - commercial 579 556 385 371 194 185 Retail - industrial 677 648 386 384 291 264 Wholesale 142 127 44 44 98 83 Bulk power and other 91 81 40 61 51 20 Total Electric Utility 2,357 2,257 1,343 1,332 1,014 925 Gas Utility: Retail - residential 162 146 90 79 72 67 Retail - commercial 85 70 47 38 38 32 Retail - industrial 11 8 8 5 3 3 Transportation/other 31 29 20 19 11 10 Total Gas Utility 289 253 165 141 124 112 Other Utility: Steam 27 27 27 27 — — Other utility 9 5 8 4 1 1 Total Other Utility 36 32 35 31 1 1 Non-Utility and Other: Travero and other 60 57 — — — — Total Non-Utility and Other 60 57 — — — — Total revenues $2,742 $2,599 $1,543 $1,504 $1,139 $1,038 |
WPL [Member] | |
Disaggregation of Revenue [Line Items] | |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions): Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $348 $328 $207 $189 $141 $139 Retail - commercial 232 210 160 142 72 68 Retail - industrial 265 241 158 149 107 92 Wholesale 55 47 18 17 37 30 Bulk power and other 39 26 12 22 27 4 Total Electric Utility 939 852 555 519 384 333 Gas Utility: Retail - residential 24 22 14 12 10 10 Retail - commercial 13 10 8 6 5 4 Retail - industrial 3 2 3 1 — 1 Transportation/other 10 8 6 5 4 3 Total Gas Utility 50 42 31 24 19 18 Other Utility: Steam 9 8 9 8 — — Other utility 4 2 4 2 — — Total Other Utility 13 10 13 10 — — Non-Utility and Other: Travero and other 22 16 — — — — Total Non-Utility and Other 22 16 — — — — Total revenues $1,024 $920 $599 $553 $403 $351 Alliant Energy IPL WPL Nine Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $868 $845 $488 $472 $380 $373 Retail - commercial 579 556 385 371 194 185 Retail - industrial 677 648 386 384 291 264 Wholesale 142 127 44 44 98 83 Bulk power and other 91 81 40 61 51 20 Total Electric Utility 2,357 2,257 1,343 1,332 1,014 925 Gas Utility: Retail - residential 162 146 90 79 72 67 Retail - commercial 85 70 47 38 38 32 Retail - industrial 11 8 8 5 3 3 Transportation/other 31 29 20 19 11 10 Total Gas Utility 289 253 165 141 124 112 Other Utility: Steam 27 27 27 27 — — Other utility 9 5 8 4 1 1 Total Other Utility 36 32 35 31 1 1 Non-Utility and Other: Travero and other 60 57 — — — — Total Non-Utility and Other 60 57 — — — — Total revenues $2,742 $2,599 $1,543 $1,504 $1,139 $1,038 |
Income Taxes
Income Taxes | 9 Months Ended |
Sep. 30, 2021 | |
Income Taxes [Line Items] | |
Income Taxes | INCOME TAXES Income Tax Rates - Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences. The decreases in Alliant Energy’s and WPL’s overall effective income tax rates for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements. Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Overall income tax rate (9%) (9%) (13%) (9%) (8%) (14%) (11%) (14%) (19%) (7%) (24%) (8%) Deferred Tax Assets and Liabilities - Carryforwards - At September 30, 2021, carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2037 $170 $157 $1 State net operating losses 2021-2041 592 24 2 Federal tax credits 2022-2041 547 339 186 |
IPL [Member] | |
Income Taxes [Line Items] | |
Income Taxes | INCOME TAXES Income Tax Rates - Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences. The decreases in Alliant Energy’s and WPL’s overall effective income tax rates for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements. Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Overall income tax rate (9%) (9%) (13%) (9%) (8%) (14%) (11%) (14%) (19%) (7%) (24%) (8%) Deferred Tax Assets and Liabilities - Carryforwards - At September 30, 2021, carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2037 $170 $157 $1 State net operating losses 2021-2041 592 24 2 Federal tax credits 2022-2041 547 339 186 |
WPL [Member] | |
Income Taxes [Line Items] | |
Income Taxes | INCOME TAXES Income Tax Rates - Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences. The decreases in Alliant Energy’s and WPL’s overall effective income tax rates for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements. Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Overall income tax rate (9%) (9%) (13%) (9%) (8%) (14%) (11%) (14%) (19%) (7%) (24%) (8%) Deferred Tax Assets and Liabilities - Carryforwards - At September 30, 2021, carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2037 $170 $157 $1 State net operating losses 2021-2041 592 24 2 Federal tax credits 2022-2041 547 339 186 |
Benefit Plans
Benefit Plans | 9 Months Ended |
Sep. 30, 2021 | |
Benefit Plans | BENEFIT PLANS NOTE 10(a) Pension and OPEB 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 below (in millions). For IPL and WPL, amounts are for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $2 $3 $8 $8 $1 $1 $3 $3 Interest cost 9 10 26 32 1 2 3 5 Expected return on plan assets (17) (17) (51) (52) (1) (1) (3) (4) Amortization of prior service credit (1) — (1) — — — — — Amortization of actuarial loss 10 9 29 26 1 — 3 2 Settlement losses (a) — — — 4 — — — — $3 $5 $11 $18 $2 $2 $6 $6 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $2 $5 $5 $— $— $1 $1 Interest cost 4 5 12 15 1 1 2 2 Expected return on plan assets (8) (8) (24) (24) (1) (1) (3) (3) Amortization of actuarial loss 5 4 13 11 — — 1 1 $2 $3 $6 $7 $— $— $1 $1 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $1 $3 $3 $1 $— $1 $1 Interest cost 3 5 11 14 — 1 1 2 Expected return on plan assets (8) (8) (23) (23) — (1) — (1) Amortization of actuarial loss 5 4 14 12 1 1 2 2 $1 $2 $5 $6 $2 $1 $4 $4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. NOTE 10(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 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Compensation expense $4 $5 $9 $10 $2 $3 $5 $6 $2 $2 $4 $4 Income tax benefits 1 1 3 3 — 1 1 2 — — 1 1 As of September 30, 2021, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $7 million, $4 million and $3 million, respectively, which is expected to be recognized over a weighted average period of between 1 year and 2 years. For the nine months ended September 30, 2021, performance shares, performance restricted stock units and restricted stock units were granted to key employees as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards. Weighted Average Grants Grant Date Fair Value Performance shares 73,112 $46.19 Performance restricted stock units 73,112 48.66 Restricted stock units 80,152 48.65 As of September 30, 2021, 491,406 shares were included in the calculation of diluted EPS related to the nonvested equity awards. |
IPL [Member] | |
Benefit Plans | BENEFIT PLANS NOTE 10(a) Pension and OPEB 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 below (in millions). For IPL and WPL, amounts are for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $2 $3 $8 $8 $1 $1 $3 $3 Interest cost 9 10 26 32 1 2 3 5 Expected return on plan assets (17) (17) (51) (52) (1) (1) (3) (4) Amortization of prior service credit (1) — (1) — — — — — Amortization of actuarial loss 10 9 29 26 1 — 3 2 Settlement losses (a) — — — 4 — — — — $3 $5 $11 $18 $2 $2 $6 $6 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $2 $5 $5 $— $— $1 $1 Interest cost 4 5 12 15 1 1 2 2 Expected return on plan assets (8) (8) (24) (24) (1) (1) (3) (3) Amortization of actuarial loss 5 4 13 11 — — 1 1 $2 $3 $6 $7 $— $— $1 $1 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $1 $3 $3 $1 $— $1 $1 Interest cost 3 5 11 14 — 1 1 2 Expected return on plan assets (8) (8) (23) (23) — (1) — (1) Amortization of actuarial loss 5 4 14 12 1 1 2 2 $1 $2 $5 $6 $2 $1 $4 $4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. NOTE 10(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 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Compensation expense $4 $5 $9 $10 $2 $3 $5 $6 $2 $2 $4 $4 Income tax benefits 1 1 3 3 — 1 1 2 — — 1 1 As of September 30, 2021, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $7 million, $4 million and $3 million, respectively, which is expected to be recognized over a weighted average period of between 1 year and 2 years. For the nine months ended September 30, 2021, performance shares, performance restricted stock units and restricted stock units were granted to key employees as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards. Weighted Average Grants Grant Date Fair Value Performance shares 73,112 $46.19 Performance restricted stock units 73,112 48.66 Restricted stock units 80,152 48.65 As of September 30, 2021, 491,406 shares were included in the calculation of diluted EPS related to the nonvested equity awards. |
WPL [Member] | |
Benefit Plans | BENEFIT PLANS NOTE 10(a) Pension and OPEB 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 below (in millions). For IPL and WPL, amounts are for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $2 $3 $8 $8 $1 $1 $3 $3 Interest cost 9 10 26 32 1 2 3 5 Expected return on plan assets (17) (17) (51) (52) (1) (1) (3) (4) Amortization of prior service credit (1) — (1) — — — — — Amortization of actuarial loss 10 9 29 26 1 — 3 2 Settlement losses (a) — — — 4 — — — — $3 $5 $11 $18 $2 $2 $6 $6 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $2 $5 $5 $— $— $1 $1 Interest cost 4 5 12 15 1 1 2 2 Expected return on plan assets (8) (8) (24) (24) (1) (1) (3) (3) Amortization of actuarial loss 5 4 13 11 — — 1 1 $2 $3 $6 $7 $— $— $1 $1 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $1 $3 $3 $1 $— $1 $1 Interest cost 3 5 11 14 — 1 1 2 Expected return on plan assets (8) (8) (23) (23) — (1) — (1) Amortization of actuarial loss 5 4 14 12 1 1 2 2 $1 $2 $5 $6 $2 $1 $4 $4 (a) Settlement losses related to payments made to retired executives of Alliant Energy. NOTE 10(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 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Compensation expense $4 $5 $9 $10 $2 $3 $5 $6 $2 $2 $4 $4 Income tax benefits 1 1 3 3 — 1 1 2 — — 1 1 As of September 30, 2021, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $7 million, $4 million and $3 million, respectively, which is expected to be recognized over a weighted average period of between 1 year and 2 years. For the nine months ended September 30, 2021, performance shares, performance restricted stock units and restricted stock units were granted to key employees as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards. Weighted Average Grants Grant Date Fair Value Performance shares 73,112 $46.19 Performance restricted stock units 73,112 48.66 Restricted stock units 80,152 48.65 As of September 30, 2021, 491,406 shares were included in the calculation of diluted EPS related to the nonvested equity awards. |
Asset Retirement Obligations
Asset Retirement Obligations | 9 Months Ended |
Sep. 30, 2021 | |
Asset Retirement Obligations [Line Items] | |
Asset Retirement Obligations | ASSET RETIREMENT OBLIGATIONS A reconciliation of the changes in asset retirement obligations associated with long-lived assets for the nine months ended September 30, 2021 is as follows (in millions): Alliant Energy IPL Balance, January 1 $251 $177 Revisions in estimated cash flows 37 32 Liabilities settled (10) (8) Liabilities incurred 1 — Accretion expense 6 4 Balance, September 30 $285 $205 |
IPL [Member] | |
Asset Retirement Obligations [Line Items] | |
Asset Retirement Obligations | ASSET RETIREMENT OBLIGATIONS A reconciliation of the changes in asset retirement obligations associated with long-lived assets for the nine months ended September 30, 2021 is as follows (in millions): Alliant Energy IPL Balance, January 1 $251 $177 Revisions in estimated cash flows 37 32 Liabilities settled (10) (8) Liabilities incurred 1 — Accretion expense 6 4 Balance, September 30 $285 $205 |
Derivative Instruments
Derivative Instruments | 9 Months Ended |
Sep. 30, 2021 | |
Derivative Instruments [Line Items] | |
Derivative Instruments | DERIVATIVE INSTRUMENTS Commodity Derivatives - Notional Amounts - As of September 30, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands): FTRs Natural Gas Coal Diesel Fuel MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 13,265 2021-2022 189,332 2021-2030 4,280 2021-2023 3,654 2021-2022 IPL 4,014 2021-2022 103,859 2021-2030 1,807 2021-2023 — — WPL 9,251 2021-2022 85,473 2021-2030 2,473 2021-2023 3,654 2021-2022 Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $158 $24 $72 $20 $86 $4 Non-current derivative assets 78 10 43 9 35 1 Current derivative liabilities 3 9 3 3 — 6 Non-current derivative liabilities 1 16 1 9 — 7 During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s derivative assets increased and derivative liabilities decreased primarily as a result of higher natural gas prices. Based on IPL’s and WPL’s natural gas cost recovery mechanisms, this resulted in corresponding decreases in derivative regulatory assets and increases in derivative regulatory liabilities on the balance sheets. 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, 2021 and December 31, 2020, 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, 2021 and December 31, 2020. 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, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands): FTRs Natural Gas Coal Diesel Fuel MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 13,265 2021-2022 189,332 2021-2030 4,280 2021-2023 3,654 2021-2022 IPL 4,014 2021-2022 103,859 2021-2030 1,807 2021-2023 — — WPL 9,251 2021-2022 85,473 2021-2030 2,473 2021-2023 3,654 2021-2022 Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $158 $24 $72 $20 $86 $4 Non-current derivative assets 78 10 43 9 35 1 Current derivative liabilities 3 9 3 3 — 6 Non-current derivative liabilities 1 16 1 9 — 7 During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s derivative assets increased and derivative liabilities decreased primarily as a result of higher natural gas prices. Based on IPL’s and WPL’s natural gas cost recovery mechanisms, this resulted in corresponding decreases in derivative regulatory assets and increases in derivative regulatory liabilities on the balance sheets. 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, 2021 and December 31, 2020, 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, 2021 and December 31, 2020. 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, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands): FTRs Natural Gas Coal Diesel Fuel MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 13,265 2021-2022 189,332 2021-2030 4,280 2021-2023 3,654 2021-2022 IPL 4,014 2021-2022 103,859 2021-2030 1,807 2021-2023 — — WPL 9,251 2021-2022 85,473 2021-2030 2,473 2021-2023 3,654 2021-2022 Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $158 $24 $72 $20 $86 $4 Non-current derivative assets 78 10 43 9 35 1 Current derivative liabilities 3 9 3 3 — 6 Non-current derivative liabilities 1 16 1 9 — 7 During the nine months ended September 30, 2021, Alliant Energy’s, IPL’s and WPL’s derivative assets increased and derivative liabilities decreased primarily as a result of higher natural gas prices. Based on IPL’s and WPL’s natural gas cost recovery mechanisms, this resulted in corresponding decreases in derivative regulatory assets and increases in derivative regulatory liabilities on the balance sheets. 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, 2021 and December 31, 2020, 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, 2021 and December 31, 2020. 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. |
Fair Value Measurements
Fair Value Measurements | 9 Months Ended |
Sep. 30, 2021 | |
Fair Value Measurements | FAIR VALUE MEASUREMENTS 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, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 236 — 207 29 236 34 — 5 29 34 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 25 — 25 — 25 Long-term debt (incl. current maturities) 7,075 — 8,083 1 8,084 6,777 — 8,107 2 8,109 IPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 115 — 96 19 115 29 — 3 26 29 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 12 — 12 — 12 Long-term debt 3,347 — 3,849 — 3,849 3,345 — 4,021 — 4,021 WPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $121 $— $111 $10 $121 $5 $— $2 $3 $5 Liabilities: Derivatives — — — — — 13 — 13 — 13 Long-term debt 2,429 — 2,869 — 2,869 2,130 — 2,690 — 2,690 Information for Alliant Energy’s and IPL’s fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions). Such amounts for WPL were not material. Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $39 $36 $154 $194 Total net gains included in changes in net assets (realized/unrealized) 5 — — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (7) (5) 10 7 Ending balance, September 30 $29 $30 $164 $201 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 $5 ($1) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $29 $21 $188 $188 Total net gains included in changes in net assets (realized/unrealized) 6 8 — — Transfers out of Level 3 (8) — — — Purchases 21 14 — — Sales — (1) — — Settlements (a) (19) (12) (24) 13 Ending balance, September 30 $29 $30 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $6 $8 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $30 $32 $154 $194 Total net gains (losses) included in changes in net assets (realized/unrealized) 2 (1) — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (5) (4) 10 7 Ending balance, September 30 $19 $26 $164 $201 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 $2 ($1) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $26 $18 $188 $188 Total net gains included in changes in net assets (realized/unrealized) — 7 — — Transfers out of Level 3 (8) — — — Purchases 16 11 — — Sales — (1) — — Settlements (a) (15) (9) (24) 13 Ending balance, September 30 $19 $26 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $— $7 $— $— (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold. Commodity Contracts - The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2021 $7 $22 $5 $14 $2 $8 December 31, 2020 18 11 17 9 1 2 |
IPL [Member] | |
Fair Value Measurements | FAIR VALUE MEASUREMENTS 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, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 236 — 207 29 236 34 — 5 29 34 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 25 — 25 — 25 Long-term debt (incl. current maturities) 7,075 — 8,083 1 8,084 6,777 — 8,107 2 8,109 IPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 115 — 96 19 115 29 — 3 26 29 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 12 — 12 — 12 Long-term debt 3,347 — 3,849 — 3,849 3,345 — 4,021 — 4,021 WPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $121 $— $111 $10 $121 $5 $— $2 $3 $5 Liabilities: Derivatives — — — — — 13 — 13 — 13 Long-term debt 2,429 — 2,869 — 2,869 2,130 — 2,690 — 2,690 Information for Alliant Energy’s and IPL’s fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions). Such amounts for WPL were not material. Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $39 $36 $154 $194 Total net gains included in changes in net assets (realized/unrealized) 5 — — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (7) (5) 10 7 Ending balance, September 30 $29 $30 $164 $201 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 $5 ($1) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $29 $21 $188 $188 Total net gains included in changes in net assets (realized/unrealized) 6 8 — — Transfers out of Level 3 (8) — — — Purchases 21 14 — — Sales — (1) — — Settlements (a) (19) (12) (24) 13 Ending balance, September 30 $29 $30 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $6 $8 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $30 $32 $154 $194 Total net gains (losses) included in changes in net assets (realized/unrealized) 2 (1) — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (5) (4) 10 7 Ending balance, September 30 $19 $26 $164 $201 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 $2 ($1) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $26 $18 $188 $188 Total net gains included in changes in net assets (realized/unrealized) — 7 — — Transfers out of Level 3 (8) — — — Purchases 16 11 — — Sales — (1) — — Settlements (a) (15) (9) (24) 13 Ending balance, September 30 $19 $26 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $— $7 $— $— (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold. Commodity Contracts - The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2021 $7 $22 $5 $14 $2 $8 December 31, 2020 18 11 17 9 1 2 |
WPL [Member] | |
Fair Value Measurements | FAIR VALUE MEASUREMENTS 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, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 236 — 207 29 236 34 — 5 29 34 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 25 — 25 — 25 Long-term debt (incl. current maturities) 7,075 — 8,083 1 8,084 6,777 — 8,107 2 8,109 IPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 115 — 96 19 115 29 — 3 26 29 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 12 — 12 — 12 Long-term debt 3,347 — 3,849 — 3,849 3,345 — 4,021 — 4,021 WPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $121 $— $111 $10 $121 $5 $— $2 $3 $5 Liabilities: Derivatives — — — — — 13 — 13 — 13 Long-term debt 2,429 — 2,869 — 2,869 2,130 — 2,690 — 2,690 Information for Alliant Energy’s and IPL’s fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions). Such amounts for WPL were not material. Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $39 $36 $154 $194 Total net gains included in changes in net assets (realized/unrealized) 5 — — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (7) (5) 10 7 Ending balance, September 30 $29 $30 $164 $201 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 $5 ($1) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $29 $21 $188 $188 Total net gains included in changes in net assets (realized/unrealized) 6 8 — — Transfers out of Level 3 (8) — — — Purchases 21 14 — — Sales — (1) — — Settlements (a) (19) (12) (24) 13 Ending balance, September 30 $29 $30 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $6 $8 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $30 $32 $154 $194 Total net gains (losses) included in changes in net assets (realized/unrealized) 2 (1) — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (5) (4) 10 7 Ending balance, September 30 $19 $26 $164 $201 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 $2 ($1) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $26 $18 $188 $188 Total net gains included in changes in net assets (realized/unrealized) — 7 — — Transfers out of Level 3 (8) — — — Purchases 16 11 — — Sales — (1) — — Settlements (a) (15) (9) (24) 13 Ending balance, September 30 $19 $26 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $— $7 $— $— (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold. Commodity Contracts - The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2021 $7 $22 $5 $14 $2 $8 December 31, 2020 18 11 17 9 1 2 |
Commitments And Contingencies
Commitments And Contingencies | 9 Months Ended |
Sep. 30, 2021 | |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES NOTE 14(a) Capital Purchase Commitments - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects, including WPL’s expansion of solar generation. At September 30, 2021, Alliant Energy’s and WPL’s minimum future commitments for these projects were $95 million and $93 million, respectively. NOTE 14(b) Other Purchase Commitments - 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 commitments associated with other goods and services. At September 30, 2021, related minimum future commitments were as follows (in millions): Alliant Energy IPL WPL Natural gas $985 $514 $471 Coal 82 54 28 Other (a) 134 71 39 $1,201 $639 $538 (a) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2021. NOTE 14(c) Guarantees and Indemnifications - Whiting Petroleum - Whiting Petroleum is an independent oil and gas company. In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. 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 multiple general partnership agreements in the oil and gas industry. The guarantees do not include a maximum limit. Based on information made available to Alliant Energy by Whiting Petroleum, the Whiting Petroleum affiliate holds an approximate 6% share in the partnerships, and currently known obligations include costs associated with the future abandonment of certain facilities owned by the partnerships. The general partnerships were formed under California law, and Alliant Energy Resources, LLC may need to perform under the guarantees if the affiliate of Whiting Petroleum is unable to meet its partnership obligations. As of September 30, 2021, the currently known partnership obligations for the abandonment obligations are estimated at $68 million, which represents Alliant Energy’s currently estimated maximum exposure under the guarantees. Alliant Energy estimates its expected loss to be a portion of the $68 million of known partnership abandonment obligations of the Whiting Petroleum affiliate and the other partners. Alliant Energy is not aware of any material liabilities related to these guarantees that it is probable that it will be obligated to pay; however, as of both September 30, 2021 and December 31, 2020, a liability of $5 million is recorded in “Other liabilities” on Alliant Energy’s balance sheets for expected credit losses related to the contingent obligations that are in the scope of these guarantees. Non-utility Wind Farm in Oklahoma - In 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-utility wind farm located in Oklahoma. The wind farm provides electricity to a third party under a long-term PPA. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and PPA. Alliant Energy’s obligations under the operating agreement were $67 million as of September 30, 2021 and will reduce annually until expiring in July 2047. Alliant Energy’s obligations under the PPA 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, 2021 and December 31, 2020. NOTE 14(d) 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. At September 30, 2021, 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, which are not discounted, were as follows (in millions). At September 30, 2021, such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $9 - $24 $6 - $19 Current and non-current environmental liabilities $12 $9 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 Clean Air Act 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 fuel switching or retiring Burlington by December 31, 2021 and Prairie Creek Units 1 and 3 by December 31, 2025. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to compliance with the terms of the Consent Decree 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 and electric and gas distribution systems to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including the Clean Air Act. |
IPL [Member] | |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES NOTE 14(a) Capital Purchase Commitments - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects, including WPL’s expansion of solar generation. At September 30, 2021, Alliant Energy’s and WPL’s minimum future commitments for these projects were $95 million and $93 million, respectively. NOTE 14(b) Other Purchase Commitments - 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 commitments associated with other goods and services. At September 30, 2021, related minimum future commitments were as follows (in millions): Alliant Energy IPL WPL Natural gas $985 $514 $471 Coal 82 54 28 Other (a) 134 71 39 $1,201 $639 $538 (a) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2021. NOTE 14(c) Guarantees and Indemnifications - Whiting Petroleum - Whiting Petroleum is an independent oil and gas company. In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. 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 multiple general partnership agreements in the oil and gas industry. The guarantees do not include a maximum limit. Based on information made available to Alliant Energy by Whiting Petroleum, the Whiting Petroleum affiliate holds an approximate 6% share in the partnerships, and currently known obligations include costs associated with the future abandonment of certain facilities owned by the partnerships. The general partnerships were formed under California law, and Alliant Energy Resources, LLC may need to perform under the guarantees if the affiliate of Whiting Petroleum is unable to meet its partnership obligations. As of September 30, 2021, the currently known partnership obligations for the abandonment obligations are estimated at $68 million, which represents Alliant Energy’s currently estimated maximum exposure under the guarantees. Alliant Energy estimates its expected loss to be a portion of the $68 million of known partnership abandonment obligations of the Whiting Petroleum affiliate and the other partners. Alliant Energy is not aware of any material liabilities related to these guarantees that it is probable that it will be obligated to pay; however, as of both September 30, 2021 and December 31, 2020, a liability of $5 million is recorded in “Other liabilities” on Alliant Energy’s balance sheets for expected credit losses related to the contingent obligations that are in the scope of these guarantees. Non-utility Wind Farm in Oklahoma - In 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-utility wind farm located in Oklahoma. The wind farm provides electricity to a third party under a long-term PPA. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and PPA. Alliant Energy’s obligations under the operating agreement were $67 million as of September 30, 2021 and will reduce annually until expiring in July 2047. Alliant Energy’s obligations under the PPA 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, 2021 and December 31, 2020. NOTE 14(d) 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. At September 30, 2021, 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, which are not discounted, were as follows (in millions). At September 30, 2021, such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $9 - $24 $6 - $19 Current and non-current environmental liabilities $12 $9 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 Clean Air Act 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 fuel switching or retiring Burlington by December 31, 2021 and Prairie Creek Units 1 and 3 by December 31, 2025. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to compliance with the terms of the Consent Decree 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 and electric and gas distribution systems to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including the Clean Air Act. |
WPL [Member] | |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES NOTE 14(a) Capital Purchase Commitments - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects, including WPL’s expansion of solar generation. At September 30, 2021, Alliant Energy’s and WPL’s minimum future commitments for these projects were $95 million and $93 million, respectively. NOTE 14(b) Other Purchase Commitments - 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 commitments associated with other goods and services. At September 30, 2021, related minimum future commitments were as follows (in millions): Alliant Energy IPL WPL Natural gas $985 $514 $471 Coal 82 54 28 Other (a) 134 71 39 $1,201 $639 $538 (a) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2021. NOTE 14(c) Guarantees and Indemnifications - Whiting Petroleum - Whiting Petroleum is an independent oil and gas company. In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. 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 multiple general partnership agreements in the oil and gas industry. The guarantees do not include a maximum limit. Based on information made available to Alliant Energy by Whiting Petroleum, the Whiting Petroleum affiliate holds an approximate 6% share in the partnerships, and currently known obligations include costs associated with the future abandonment of certain facilities owned by the partnerships. The general partnerships were formed under California law, and Alliant Energy Resources, LLC may need to perform under the guarantees if the affiliate of Whiting Petroleum is unable to meet its partnership obligations. As of September 30, 2021, the currently known partnership obligations for the abandonment obligations are estimated at $68 million, which represents Alliant Energy’s currently estimated maximum exposure under the guarantees. Alliant Energy estimates its expected loss to be a portion of the $68 million of known partnership abandonment obligations of the Whiting Petroleum affiliate and the other partners. Alliant Energy is not aware of any material liabilities related to these guarantees that it is probable that it will be obligated to pay; however, as of both September 30, 2021 and December 31, 2020, a liability of $5 million is recorded in “Other liabilities” on Alliant Energy’s balance sheets for expected credit losses related to the contingent obligations that are in the scope of these guarantees. Non-utility Wind Farm in Oklahoma - In 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-utility wind farm located in Oklahoma. The wind farm provides electricity to a third party under a long-term PPA. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and PPA. Alliant Energy’s obligations under the operating agreement were $67 million as of September 30, 2021 and will reduce annually until expiring in July 2047. Alliant Energy’s obligations under the PPA 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, 2021 and December 31, 2020. NOTE 14(d) 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. At September 30, 2021, 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, which are not discounted, were as follows (in millions). At September 30, 2021, such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $9 - $24 $6 - $19 Current and non-current environmental liabilities $12 $9 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 Clean Air Act 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 fuel switching or retiring Burlington by December 31, 2021 and Prairie Creek Units 1 and 3 by December 31, 2025. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to compliance with the terms of the Consent Decree 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 and electric and gas distribution systems to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including the Clean Air Act. |
Segments Of Business
Segments Of Business | 9 Months Ended |
Sep. 30, 2021 | |
Segment Reporting Information [Line Items] | |
Segments Of Business | SEGMENTS OF BUSINESS Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2021 Revenues $939 $50 $13 $1,002 $22 $1,024 Operating income (loss) 290 (5) (5) 280 9 289 Net income attributable to Alliant Energy common shareowners 250 6 256 Three Months Ended September 30, 2020 Revenues $852 $42 $10 $904 $16 $920 Operating income (loss) 251 (1) 1 251 21 272 Net income attributable to Alliant Energy common shareowners 221 25 246 Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2021 Revenues $2,357 $289 $36 $2,682 $60 $2,742 Operating income (loss) 601 42 (4) 639 24 663 Net income attributable to Alliant Energy common shareowners 537 34 571 Nine Months Ended September 30, 2020 Revenues $2,257 $253 $32 $2,542 $57 $2,599 Operating income 549 48 5 602 26 628 Net income attributable to Alliant Energy common shareowners 510 40 550 IPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $555 $31 $13 $599 Operating income (loss) 186 (3) (3) 180 Net income available for common stock 157 Three Months Ended September 30, 2020 Revenues $519 $24 $10 $553 Operating income 159 1 2 162 Net income available for common stock 148 Nine Months Ended September 30, 2021 Revenues $1,343 $165 $35 $1,543 Operating income (loss) 365 30 (1) 394 Net income available for common stock 322 Nine Months Ended September 30, 2020 Revenues $1,332 $141 $31 $1,504 Operating income 308 34 5 347 Net income available for common stock 290 WPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $384 $19 $— $403 Operating income (loss) 104 (2) (2) 100 Net income 93 Three Months Ended September 30, 2020 Revenues $333 $18 $— $351 Operating income (loss) 92 (2) (1) 89 Net income 73 Nine Months Ended September 30, 2021 Revenues $1,014 $124 $1 $1,139 Operating income (loss) 236 12 (3) 245 Net income 215 Nine Months Ended September 30, 2020 Revenues $925 $112 $1 $1,038 Operating income 241 14 — 255 Net income 220 |
IPL [Member] | |
Segment Reporting Information [Line Items] | |
Segments Of Business | Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2021 Revenues $939 $50 $13 $1,002 $22 $1,024 Operating income (loss) 290 (5) (5) 280 9 289 Net income attributable to Alliant Energy common shareowners 250 6 256 Three Months Ended September 30, 2020 Revenues $852 $42 $10 $904 $16 $920 Operating income (loss) 251 (1) 1 251 21 272 Net income attributable to Alliant Energy common shareowners 221 25 246 Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2021 Revenues $2,357 $289 $36 $2,682 $60 $2,742 Operating income (loss) 601 42 (4) 639 24 663 Net income attributable to Alliant Energy common shareowners 537 34 571 Nine Months Ended September 30, 2020 Revenues $2,257 $253 $32 $2,542 $57 $2,599 Operating income 549 48 5 602 26 628 Net income attributable to Alliant Energy common shareowners 510 40 550 IPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $555 $31 $13 $599 Operating income (loss) 186 (3) (3) 180 Net income available for common stock 157 Three Months Ended September 30, 2020 Revenues $519 $24 $10 $553 Operating income 159 1 2 162 Net income available for common stock 148 Nine Months Ended September 30, 2021 Revenues $1,343 $165 $35 $1,543 Operating income (loss) 365 30 (1) 394 Net income available for common stock 322 Nine Months Ended September 30, 2020 Revenues $1,332 $141 $31 $1,504 Operating income 308 34 5 347 Net income available for common stock 290 WPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $384 $19 $— $403 Operating income (loss) 104 (2) (2) 100 Net income 93 Three Months Ended September 30, 2020 Revenues $333 $18 $— $351 Operating income (loss) 92 (2) (1) 89 Net income 73 Nine Months Ended September 30, 2021 Revenues $1,014 $124 $1 $1,139 Operating income (loss) 236 12 (3) 245 Net income 215 Nine Months Ended September 30, 2020 Revenues $925 $112 $1 $1,038 Operating income 241 14 — 255 Net income 220 |
WPL [Member] | |
Segment Reporting Information [Line Items] | |
Segments Of Business | Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2021 Revenues $939 $50 $13 $1,002 $22 $1,024 Operating income (loss) 290 (5) (5) 280 9 289 Net income attributable to Alliant Energy common shareowners 250 6 256 Three Months Ended September 30, 2020 Revenues $852 $42 $10 $904 $16 $920 Operating income (loss) 251 (1) 1 251 21 272 Net income attributable to Alliant Energy common shareowners 221 25 246 Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2021 Revenues $2,357 $289 $36 $2,682 $60 $2,742 Operating income (loss) 601 42 (4) 639 24 663 Net income attributable to Alliant Energy common shareowners 537 34 571 Nine Months Ended September 30, 2020 Revenues $2,257 $253 $32 $2,542 $57 $2,599 Operating income 549 48 5 602 26 628 Net income attributable to Alliant Energy common shareowners 510 40 550 IPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $555 $31 $13 $599 Operating income (loss) 186 (3) (3) 180 Net income available for common stock 157 Three Months Ended September 30, 2020 Revenues $519 $24 $10 $553 Operating income 159 1 2 162 Net income available for common stock 148 Nine Months Ended September 30, 2021 Revenues $1,343 $165 $35 $1,543 Operating income (loss) 365 30 (1) 394 Net income available for common stock 322 Nine Months Ended September 30, 2020 Revenues $1,332 $141 $31 $1,504 Operating income 308 34 5 347 Net income available for common stock 290 WPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $384 $19 $— $403 Operating income (loss) 104 (2) (2) 100 Net income 93 Three Months Ended September 30, 2020 Revenues $333 $18 $— $351 Operating income (loss) 92 (2) (1) 89 Net income 73 Nine Months Ended September 30, 2021 Revenues $1,014 $124 $1 $1,139 Operating income (loss) 236 12 (3) 245 Net income 215 Nine Months Ended September 30, 2020 Revenues $925 $112 $1 $1,038 Operating income 241 14 — 255 Net income 220 |
Related Parties
Related Parties | 9 Months Ended |
Sep. 30, 2021 | |
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 2021 2020 2021 2020 2021 2020 2021 2020 Corporate Services billings $50 $53 $138 $134 $37 $41 $113 $108 Sales credited 4 10 9 35 16 — 23 4 Purchases billed 105 110 347 248 24 39 71 79 Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Net payables to Corporate Services $109 $110 $80 $73 ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC 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 2021 2020 2021 2020 ATC billings to WPL $29 $27 $91 $80 WPL billings to ATC 4 2 13 8 WPL owed ATC net amounts of $8 million as of September 30, 2021 and $9 million as of December 31, 2020. |
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 2021 2020 2021 2020 2021 2020 2021 2020 Corporate Services billings $50 $53 $138 $134 $37 $41 $113 $108 Sales credited 4 10 9 35 16 — 23 4 Purchases billed 105 110 347 248 24 39 71 79 Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Net payables to Corporate Services $109 $110 $80 $73 |
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 2021 2020 2021 2020 2021 2020 2021 2020 Corporate Services billings $50 $53 $138 $134 $37 $41 $113 $108 Sales credited 4 10 9 35 16 — 23 4 Purchases billed 105 110 347 248 24 39 71 79 Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Net payables to Corporate Services $109 $110 $80 $73 ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC 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 2021 2020 2021 2020 ATC billings to WPL $29 $27 $91 $80 WPL billings to ATC 4 2 13 8 WPL owed ATC net amounts of $8 million as of September 30, 2021 and $9 million as of December 31, 2020. |
Summary Of Significant Accoun_2
Summary Of Significant Accounting Policies (Policy) | 9 Months Ended |
Sep. 30, 2021 | |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. 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 2020 Form 10-K . |
General, Use of Estimates | 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. |
Asset Impairments | Property, Plant and Equipment of Regulated Operations - In the second quarter of 2021, WPL received approval from MISO to retire Columbia Units 1 and 2, which had a net book value of approximately $470 million in aggregate as of September 30, 2021, and currently anticipates retiring Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024. Alliant Energy and WPL concluded that Columbia Units 1 and 2 met the criteria to be considered probable of abandonment as of September 30, 2021. WPL is currently allowed a full recovery of and a full return on these EGUs from both its retail and wholesale customers, and as a result, Alliant Energy and WPL concluded that no disallowance was required as of September 30, 2021. |
IPL [Member] | |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. 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 2020 Form 10-K . |
General, Use of Estimates | 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. |
Asset Impairments | Property, Plant and Equipment of Regulated Operations - In the second quarter of 2021, WPL received approval from MISO to retire Columbia Units 1 and 2, which had a net book value of approximately $470 million in aggregate as of September 30, 2021, and currently anticipates retiring Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024. Alliant Energy and WPL concluded that Columbia Units 1 and 2 met the criteria to be considered probable of abandonment as of September 30, 2021. WPL is currently allowed a full recovery of and a full return on these EGUs from both its retail and wholesale customers, and as a result, Alliant Energy and WPL concluded that no disallowance was required as of September 30, 2021. |
WPL [Member] | |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. 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 2020 Form 10-K . |
General, Use of Estimates | 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. |
Asset Impairments | Property, Plant and Equipment of Regulated Operations - In the second quarter of 2021, WPL received approval from MISO to retire Columbia Units 1 and 2, which had a net book value of approximately $470 million in aggregate as of September 30, 2021, and currently anticipates retiring Columbia Unit 1 by the end of 2023 and Columbia Unit 2 by the end of 2024. Alliant Energy and WPL concluded that Columbia Units 1 and 2 met the criteria to be considered probable of abandonment as of September 30, 2021. WPL is currently allowed a full recovery of and a full return on these EGUs from both its retail and wholesale customers, and as a result, Alliant Energy and WPL concluded that no disallowance was required as of September 30, 2021. |
Regulatory Matters (Tables)
Regulatory Matters (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
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 $931 $890 $881 $843 $50 $47 Pension and OPEB costs 549 580 276 291 273 289 Asset retirement obligations 124 119 85 81 39 38 Assets retired early 98 113 69 77 29 36 IPL’s DAEC PPA amendment 96 110 96 110 — — WPL’s Western Wisconsin gas distribution expansion investments 53 55 — — 53 55 Commodity cost recovery 32 4 17 1 15 3 Derivatives 4 26 4 13 — 13 Other 131 113 79 67 52 46 $2,018 $2,010 $1,507 $1,483 $511 $527 |
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, Tax-related $611 $732 $313 $331 $298 $401 Cost of removal obligations 383 367 252 238 131 129 Derivatives 221 28 104 25 117 3 Electric transmission cost recovery 53 68 29 39 24 29 WPL’s West Riverside liquidated damages 40 38 — — 40 38 Other 53 73 22 43 31 30 $1,361 $1,306 $720 $676 $641 $630 |
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 $931 $890 $881 $843 $50 $47 Pension and OPEB costs 549 580 276 291 273 289 Asset retirement obligations 124 119 85 81 39 38 Assets retired early 98 113 69 77 29 36 IPL’s DAEC PPA amendment 96 110 96 110 — — WPL’s Western Wisconsin gas distribution expansion investments 53 55 — — 53 55 Commodity cost recovery 32 4 17 1 15 3 Derivatives 4 26 4 13 — 13 Other 131 113 79 67 52 46 $2,018 $2,010 $1,507 $1,483 $511 $527 |
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, Tax-related $611 $732 $313 $331 $298 $401 Cost of removal obligations 383 367 252 238 131 129 Derivatives 221 28 104 25 117 3 Electric transmission cost recovery 53 68 29 39 24 29 WPL’s West Riverside liquidated damages 40 38 — — 40 38 Other 53 73 22 43 31 30 $1,361 $1,306 $720 $676 $641 $630 |
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 $931 $890 $881 $843 $50 $47 Pension and OPEB costs 549 580 276 291 273 289 Asset retirement obligations 124 119 85 81 39 38 Assets retired early 98 113 69 77 29 36 IPL’s DAEC PPA amendment 96 110 96 110 — — WPL’s Western Wisconsin gas distribution expansion investments 53 55 — — 53 55 Commodity cost recovery 32 4 17 1 15 3 Derivatives 4 26 4 13 — 13 Other 131 113 79 67 52 46 $2,018 $2,010 $1,507 $1,483 $511 $527 |
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, Tax-related $611 $732 $313 $331 $298 $401 Cost of removal obligations 383 367 252 238 131 129 Derivatives 221 28 104 25 117 3 Electric transmission cost recovery 53 68 29 39 24 29 WPL’s West Riverside liquidated damages 40 38 — — 40 38 Other 53 73 22 43 31 30 $1,361 $1,306 $720 $676 $641 $630 |
Receivables (Tables)
Receivables (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
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 2021 2020 2021 2020 Maximum outstanding aggregate cash proceeds $110 $1 $110 $96 Average outstanding aggregate cash proceeds 65 1 52 12 |
Attributes of Receivables Sold Under the Receivables Agreement | The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2021 December 31, 2020 Customer accounts receivable $145 $114 Unbilled utility revenues 83 92 Receivables sold to third party 228 206 Less: cash proceeds 50 1 Deferred proceeds 178 205 Less: allowance for expected credit losses 14 17 Fair value of deferred proceeds $164 $188 |
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 2021 2020 2021 2020 Collections $607 $561 $1,589 $1,555 Write-offs, net of recoveries 4 1 7 4 |
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 2021 2020 2021 2020 Maximum outstanding aggregate cash proceeds $110 $1 $110 $96 Average outstanding aggregate cash proceeds 65 1 52 12 |
Attributes of Receivables Sold Under the Receivables Agreement | The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions): September 30, 2021 December 31, 2020 Customer accounts receivable $145 $114 Unbilled utility revenues 83 92 Receivables sold to third party 228 206 Less: cash proceeds 50 1 Deferred proceeds 178 205 Less: allowance for expected credit losses 14 17 Fair value of deferred proceeds $164 $188 |
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 2021 2020 2021 2020 Collections $607 $561 $1,589 $1,555 Write-offs, net of recoveries 4 1 7 4 |
Investments (Tables)
Investments (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Schedule of Equity Method Investments [Line Items] | |
Unconsolidated Equity Investments | Alliant Energy’s 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): Three Months Nine Months 2021 2020 2021 2020 ATC Holdings ($12) ($11) ($34) ($36) Other (1) (4) (13) (10) ($13) ($15) ($47) ($46) |
Common Equity (Tables)
Common Equity (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Schedule of Capitalization, Equity [Line Items] | |
Common Share Activity | A summary of Alliant Energy’s common stock activity was as follows: Shares outstanding, January 1, 2021 249,868,415 Shareowner Direct Plan 378,823 Equity-based compensation plans 113,549 Shares outstanding, September 30, 2021 250,360,787 |
Changes in Shareowners' Equity | A summary of changes in shareowners’ equity was as follows (in millions): Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $3 $2,722 $3,106 ($1) ($11) $200 $6,019 Net income attributable to Alliant Energy common shareowners 256 256 Common stock dividends ($0.4025 per share) (101) (101) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 5 5 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $2 $2,683 $2,874 ($1) ($10) $200 $5,748 Net income attributable to Alliant Energy common shareowners 246 246 Common stock dividends ($0.38 per share) (94) (94) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 4 (1) 3 Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $2 $2,704 $2,994 ($1) ($11) $200 $5,888 Net income attributable to Alliant Energy common shareowners 571 571 Common stock dividends ($1.2075 per share) (304) (304) Shareowner Direct Plan issuances 1 21 22 Equity-based compensation plans and other 8 8 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $2 $2,446 $2,766 $1 ($10) $200 $5,405 Net income attributable to Alliant Energy common shareowners 550 550 Common stock dividends ($1.14 per share) (281) (281) Equity forward settlements and Shareowner Direct Plan issuances 241 241 Equity-based compensation plans and other 6 (1) 5 Adoption of new accounting standard, net of tax (9) (9) Other comprehensive loss, net of tax (2) (2) Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $33 $2,802 $944 $200 $3,979 Net income available for common stock 157 157 Common stock dividends (101) (101) Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $33 $2,523 $915 $200 $3,671 Net income available for common stock 148 148 Common stock dividends (59) (59) Capital contributions from parent 170 170 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $33 $2,752 $979 $200 $3,964 Net income available for common stock 322 322 Common stock dividends (301) (301) Capital contributions from parent 50 50 Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $33 $2,348 $891 $200 $3,472 Net income available for common stock 290 290 Common stock dividends (177) (177) Capital contributions from parent 345 345 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $66 $1,669 $990 $2,725 Net income 93 93 Common stock dividends (41) (41) Capital contributions from parent 35 35 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $66 $1,459 $927 $2,452 Net income 73 73 Common stock dividends (43) (43) Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $66 $1,459 $953 $2,478 Net income 215 215 Common stock dividends (126) (126) Capital contributions from parent 245 245 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $66 $1,434 $864 $2,364 Net income 220 220 Common stock dividends (127) (127) Capital contributions from parent 25 25 Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 |
IPL [Member] | |
Schedule of Capitalization, Equity [Line Items] | |
Changes in Shareowners' Equity | A summary of changes in shareowners’ equity was as follows (in millions): Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $3 $2,722 $3,106 ($1) ($11) $200 $6,019 Net income attributable to Alliant Energy common shareowners 256 256 Common stock dividends ($0.4025 per share) (101) (101) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 5 5 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $2 $2,683 $2,874 ($1) ($10) $200 $5,748 Net income attributable to Alliant Energy common shareowners 246 246 Common stock dividends ($0.38 per share) (94) (94) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 4 (1) 3 Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $2 $2,704 $2,994 ($1) ($11) $200 $5,888 Net income attributable to Alliant Energy common shareowners 571 571 Common stock dividends ($1.2075 per share) (304) (304) Shareowner Direct Plan issuances 1 21 22 Equity-based compensation plans and other 8 8 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $2 $2,446 $2,766 $1 ($10) $200 $5,405 Net income attributable to Alliant Energy common shareowners 550 550 Common stock dividends ($1.14 per share) (281) (281) Equity forward settlements and Shareowner Direct Plan issuances 241 241 Equity-based compensation plans and other 6 (1) 5 Adoption of new accounting standard, net of tax (9) (9) Other comprehensive loss, net of tax (2) (2) Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $33 $2,802 $944 $200 $3,979 Net income available for common stock 157 157 Common stock dividends (101) (101) Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $33 $2,523 $915 $200 $3,671 Net income available for common stock 148 148 Common stock dividends (59) (59) Capital contributions from parent 170 170 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $33 $2,752 $979 $200 $3,964 Net income available for common stock 322 322 Common stock dividends (301) (301) Capital contributions from parent 50 50 Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $33 $2,348 $891 $200 $3,472 Net income available for common stock 290 290 Common stock dividends (177) (177) Capital contributions from parent 345 345 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $66 $1,669 $990 $2,725 Net income 93 93 Common stock dividends (41) (41) Capital contributions from parent 35 35 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $66 $1,459 $927 $2,452 Net income 73 73 Common stock dividends (43) (43) Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $66 $1,459 $953 $2,478 Net income 215 215 Common stock dividends (126) (126) Capital contributions from parent 245 245 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $66 $1,434 $864 $2,364 Net income 220 220 Common stock dividends (127) (127) Capital contributions from parent 25 25 Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 |
WPL [Member] | |
Schedule of Capitalization, Equity [Line Items] | |
Changes in Shareowners' Equity | A summary of changes in shareowners’ equity was as follows (in millions): Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $3 $2,722 $3,106 ($1) ($11) $200 $6,019 Net income attributable to Alliant Energy common shareowners 256 256 Common stock dividends ($0.4025 per share) (101) (101) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 5 5 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $2 $2,683 $2,874 ($1) ($10) $200 $5,748 Net income attributable to Alliant Energy common shareowners 246 246 Common stock dividends ($0.38 per share) (94) (94) Shareowner Direct Plan issuances 6 6 Equity-based compensation plans and other 4 (1) 3 Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 Alliant Energy Total Alliant Energy Common Equity Accumulated Shares in Cumulative Additional Other Deferred Preferred Common Paid-In Retained Comprehensive Compensation Stock Total Stock Capital Earnings Income (Loss) Trust of IPL Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $2 $2,704 $2,994 ($1) ($11) $200 $5,888 Net income attributable to Alliant Energy common shareowners 571 571 Common stock dividends ($1.2075 per share) (304) (304) Shareowner Direct Plan issuances 1 21 22 Equity-based compensation plans and other 8 8 Ending balance, September 30, 2021 $3 $2,733 $3,261 ($1) ($11) $200 $6,185 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $2 $2,446 $2,766 $1 ($10) $200 $5,405 Net income attributable to Alliant Energy common shareowners 550 550 Common stock dividends ($1.14 per share) (281) (281) Equity forward settlements and Shareowner Direct Plan issuances 241 241 Equity-based compensation plans and other 6 (1) 5 Adoption of new accounting standard, net of tax (9) (9) Other comprehensive loss, net of tax (2) (2) Ending balance, September 30, 2020 $2 $2,693 $3,026 ($1) ($11) $200 $5,909 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $33 $2,802 $944 $200 $3,979 Net income available for common stock 157 157 Common stock dividends (101) (101) Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $33 $2,523 $915 $200 $3,671 Net income available for common stock 148 148 Common stock dividends (59) (59) Capital contributions from parent 170 170 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 IPL Total IPL Common Equity Additional Cumulative Common Paid-In Retained Preferred Total Stock Capital Earnings Stock Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $33 $2,752 $979 $200 $3,964 Net income available for common stock 322 322 Common stock dividends (301) (301) Capital contributions from parent 50 50 Ending balance, September 30, 2021 $33 $2,802 $1,000 $200 $4,035 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $33 $2,348 $891 $200 $3,472 Net income available for common stock 290 290 Common stock dividends (177) (177) Capital contributions from parent 345 345 Ending balance, September 30, 2020 $33 $2,693 $1,004 $200 $3,930 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Three Months Ended September 30, 2021 Beginning balance, June 30, 2021 $66 $1,669 $990 $2,725 Net income 93 93 Common stock dividends (41) (41) Capital contributions from parent 35 35 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Three Months Ended September 30, 2020 Beginning balance, June 30, 2020 $66 $1,459 $927 $2,452 Net income 73 73 Common stock dividends (43) (43) Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 WPL Additional Total Common Paid-In Retained Common Stock Capital Earnings Equity Nine Months Ended September 30, 2021 Beginning balance, December 31, 2020 $66 $1,459 $953 $2,478 Net income 215 215 Common stock dividends (126) (126) Capital contributions from parent 245 245 Ending balance, September 30, 2021 $66 $1,704 $1,042 $2,812 Nine Months Ended September 30, 2020 Beginning balance, December 31, 2019 $66 $1,434 $864 $2,364 Net income 220 220 Common stock dividends (127) (127) Capital contributions from parent 25 25 Ending balance, September 30, 2020 $66 $1,459 $957 $2,482 |
Debt (Tables)
Debt (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Short-term Debt [Line Items] | |
Other Short-Term Borrowings | Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper, and Alliant Energy’s and WPL’s borrowings under the single credit facility, which currently expires in August 2023, classified as short-term debt was as follows (dollars in millions): September 30, 2021 Alliant Energy IPL WPL Amount outstanding $316 $— $3 Weighted average interest rates 0.2% N/A 0.1% Available credit facility capacity $684 $100 $397 Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Maximum amount outstanding (based on daily outstanding balances) $648 $422 $8 $— $320 $139 Average amount outstanding (based on daily outstanding balances) $560 $252 $— $— $221 $83 Weighted average interest rates 0.2% 0.2% 0.2% N/A 0.1% 0.2% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $648 $463 $19 $8 $320 $212 Average amount outstanding (based on daily outstanding balances) $479 $252 $— $— $196 $86 Weighted average interest rates 0.2% 1.1% 0.2% 0.5% 0.1% 1.2% |
IPL [Member] | |
Short-term Debt [Line Items] | |
Other Short-Term Borrowings | Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper, and Alliant Energy’s and WPL’s borrowings under the single credit facility, which currently expires in August 2023, classified as short-term debt was as follows (dollars in millions): September 30, 2021 Alliant Energy IPL WPL Amount outstanding $316 $— $3 Weighted average interest rates 0.2% N/A 0.1% Available credit facility capacity $684 $100 $397 Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Maximum amount outstanding (based on daily outstanding balances) $648 $422 $8 $— $320 $139 Average amount outstanding (based on daily outstanding balances) $560 $252 $— $— $221 $83 Weighted average interest rates 0.2% 0.2% 0.2% N/A 0.1% 0.2% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $648 $463 $19 $8 $320 $212 Average amount outstanding (based on daily outstanding balances) $479 $252 $— $— $196 $86 Weighted average interest rates 0.2% 1.1% 0.2% 0.5% 0.1% 1.2% |
WPL [Member] | |
Short-term Debt [Line Items] | |
Other Short-Term Borrowings | Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper, and Alliant Energy’s and WPL’s borrowings under the single credit facility, which currently expires in August 2023, classified as short-term debt was as follows (dollars in millions): September 30, 2021 Alliant Energy IPL WPL Amount outstanding $316 $— $3 Weighted average interest rates 0.2% N/A 0.1% Available credit facility capacity $684 $100 $397 Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Maximum amount outstanding (based on daily outstanding balances) $648 $422 $8 $— $320 $139 Average amount outstanding (based on daily outstanding balances) $560 $252 $— $— $221 $83 Weighted average interest rates 0.2% 0.2% 0.2% N/A 0.1% 0.2% Nine Months Ended September 30 Maximum amount outstanding (based on daily outstanding balances) $648 $463 $19 $8 $320 $212 Average amount outstanding (based on daily outstanding balances) $479 $252 $— $— $196 $86 Weighted average interest rates 0.2% 1.1% 0.2% 0.5% 0.1% 1.2% |
Revenues (Tables)
Revenues (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Disaggregation of Revenue [Line Items] | |
Disaggregation of Revenue | Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions): Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $348 $328 $207 $189 $141 $139 Retail - commercial 232 210 160 142 72 68 Retail - industrial 265 241 158 149 107 92 Wholesale 55 47 18 17 37 30 Bulk power and other 39 26 12 22 27 4 Total Electric Utility 939 852 555 519 384 333 Gas Utility: Retail - residential 24 22 14 12 10 10 Retail - commercial 13 10 8 6 5 4 Retail - industrial 3 2 3 1 — 1 Transportation/other 10 8 6 5 4 3 Total Gas Utility 50 42 31 24 19 18 Other Utility: Steam 9 8 9 8 — — Other utility 4 2 4 2 — — Total Other Utility 13 10 13 10 — — Non-Utility and Other: Travero and other 22 16 — — — — Total Non-Utility and Other 22 16 — — — — Total revenues $1,024 $920 $599 $553 $403 $351 Alliant Energy IPL WPL Nine Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $868 $845 $488 $472 $380 $373 Retail - commercial 579 556 385 371 194 185 Retail - industrial 677 648 386 384 291 264 Wholesale 142 127 44 44 98 83 Bulk power and other 91 81 40 61 51 20 Total Electric Utility 2,357 2,257 1,343 1,332 1,014 925 Gas Utility: Retail - residential 162 146 90 79 72 67 Retail - commercial 85 70 47 38 38 32 Retail - industrial 11 8 8 5 3 3 Transportation/other 31 29 20 19 11 10 Total Gas Utility 289 253 165 141 124 112 Other Utility: Steam 27 27 27 27 — — Other utility 9 5 8 4 1 1 Total Other Utility 36 32 35 31 1 1 Non-Utility and Other: Travero and other 60 57 — — — — Total Non-Utility and Other 60 57 — — — — Total revenues $2,742 $2,599 $1,543 $1,504 $1,139 $1,038 |
IPL [Member] | |
Disaggregation of Revenue [Line Items] | |
Disaggregation of Revenue | Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions): Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $348 $328 $207 $189 $141 $139 Retail - commercial 232 210 160 142 72 68 Retail - industrial 265 241 158 149 107 92 Wholesale 55 47 18 17 37 30 Bulk power and other 39 26 12 22 27 4 Total Electric Utility 939 852 555 519 384 333 Gas Utility: Retail - residential 24 22 14 12 10 10 Retail - commercial 13 10 8 6 5 4 Retail - industrial 3 2 3 1 — 1 Transportation/other 10 8 6 5 4 3 Total Gas Utility 50 42 31 24 19 18 Other Utility: Steam 9 8 9 8 — — Other utility 4 2 4 2 — — Total Other Utility 13 10 13 10 — — Non-Utility and Other: Travero and other 22 16 — — — — Total Non-Utility and Other 22 16 — — — — Total revenues $1,024 $920 $599 $553 $403 $351 Alliant Energy IPL WPL Nine Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $868 $845 $488 $472 $380 $373 Retail - commercial 579 556 385 371 194 185 Retail - industrial 677 648 386 384 291 264 Wholesale 142 127 44 44 98 83 Bulk power and other 91 81 40 61 51 20 Total Electric Utility 2,357 2,257 1,343 1,332 1,014 925 Gas Utility: Retail - residential 162 146 90 79 72 67 Retail - commercial 85 70 47 38 38 32 Retail - industrial 11 8 8 5 3 3 Transportation/other 31 29 20 19 11 10 Total Gas Utility 289 253 165 141 124 112 Other Utility: Steam 27 27 27 27 — — Other utility 9 5 8 4 1 1 Total Other Utility 36 32 35 31 1 1 Non-Utility and Other: Travero and other 60 57 — — — — Total Non-Utility and Other 60 57 — — — — Total revenues $2,742 $2,599 $1,543 $1,504 $1,139 $1,038 |
WPL [Member] | |
Disaggregation of Revenue [Line Items] | |
Disaggregation of Revenue | Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions): Alliant Energy IPL WPL Three Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $348 $328 $207 $189 $141 $139 Retail - commercial 232 210 160 142 72 68 Retail - industrial 265 241 158 149 107 92 Wholesale 55 47 18 17 37 30 Bulk power and other 39 26 12 22 27 4 Total Electric Utility 939 852 555 519 384 333 Gas Utility: Retail - residential 24 22 14 12 10 10 Retail - commercial 13 10 8 6 5 4 Retail - industrial 3 2 3 1 — 1 Transportation/other 10 8 6 5 4 3 Total Gas Utility 50 42 31 24 19 18 Other Utility: Steam 9 8 9 8 — — Other utility 4 2 4 2 — — Total Other Utility 13 10 13 10 — — Non-Utility and Other: Travero and other 22 16 — — — — Total Non-Utility and Other 22 16 — — — — Total revenues $1,024 $920 $599 $553 $403 $351 Alliant Energy IPL WPL Nine Months Ended September 30 2021 2020 2021 2020 2021 2020 Electric Utility: Retail - residential $868 $845 $488 $472 $380 $373 Retail - commercial 579 556 385 371 194 185 Retail - industrial 677 648 386 384 291 264 Wholesale 142 127 44 44 98 83 Bulk power and other 91 81 40 61 51 20 Total Electric Utility 2,357 2,257 1,343 1,332 1,014 925 Gas Utility: Retail - residential 162 146 90 79 72 67 Retail - commercial 85 70 47 38 38 32 Retail - industrial 11 8 8 5 3 3 Transportation/other 31 29 20 19 11 10 Total Gas Utility 289 253 165 141 124 112 Other Utility: Steam 27 27 27 27 — — Other utility 9 5 8 4 1 1 Total Other Utility 36 32 35 31 1 1 Non-Utility and Other: Travero and other 60 57 — — — — Total Non-Utility and Other 60 57 — — — — Total revenues $2,742 $2,599 $1,543 $1,504 $1,139 $1,038 |
Income Taxes (Tables)
Income Taxes (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Income Taxes [Line Items] | |
Schedule Of Effective Income Tax Rates | Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences. The decreases in Alliant Energy’s and WPL’s overall effective income tax rates for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements. Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Overall income tax rate (9%) (9%) (13%) (9%) (8%) (14%) (11%) (14%) (19%) (7%) (24%) (8%) |
Summary Of Tax Credit Carryforwards | At September 30, 2021, carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2037 $170 $157 $1 State net operating losses 2021-2041 592 24 2 Federal tax credits 2022-2041 547 339 186 |
IPL [Member] | |
Income Taxes [Line Items] | |
Schedule Of Effective Income Tax Rates | Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences. The decreases in Alliant Energy’s and WPL’s overall effective income tax rates for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements. Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Overall income tax rate (9%) (9%) (13%) (9%) (8%) (14%) (11%) (14%) (19%) (7%) (24%) (8%) |
Summary Of Tax Credit Carryforwards | At September 30, 2021, carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2037 $170 $157 $1 State net operating losses 2021-2041 592 24 2 Federal tax credits 2022-2041 547 339 186 |
WPL [Member] | |
Income Taxes [Line Items] | |
Schedule Of Effective Income Tax Rates | Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences. The decreases in Alliant Energy’s and WPL’s overall effective income tax rates for the three and nine months ended September 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements. Alliant Energy IPL WPL Three Months Nine Months Three Months Nine Months Three Months Nine Months 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Overall income tax rate (9%) (9%) (13%) (9%) (8%) (14%) (11%) (14%) (19%) (7%) (24%) (8%) |
Summary Of Tax Credit Carryforwards | At September 30, 2021, carryforwards and expiration dates were estimated as follows (in millions): Range of Expiration Dates Alliant Energy IPL WPL Federal net operating losses 2037 $170 $157 $1 State net operating losses 2021-2041 592 24 2 Federal tax credits 2022-2041 547 339 186 |
Benefit Plans (Tables)
Benefit Plans (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Defined Benefit Plan Disclosure [Line Items] | |
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 below (in millions). For IPL and WPL, amounts are for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $2 $3 $8 $8 $1 $1 $3 $3 Interest cost 9 10 26 32 1 2 3 5 Expected return on plan assets (17) (17) (51) (52) (1) (1) (3) (4) Amortization of prior service credit (1) — (1) — — — — — Amortization of actuarial loss 10 9 29 26 1 — 3 2 Settlement losses (a) — — — 4 — — — — $3 $5 $11 $18 $2 $2 $6 $6 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $2 $5 $5 $— $— $1 $1 Interest cost 4 5 12 15 1 1 2 2 Expected return on plan assets (8) (8) (24) (24) (1) (1) (3) (3) Amortization of actuarial loss 5 4 13 11 — — 1 1 $2 $3 $6 $7 $— $— $1 $1 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $1 $3 $3 $1 $— $1 $1 Interest cost 3 5 11 14 — 1 1 2 Expected return on plan assets (8) (8) (23) (23) — (1) — (1) Amortization of actuarial loss 5 4 14 12 1 1 2 2 $1 $2 $5 $6 $2 $1 $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 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Compensation expense $4 $5 $9 $10 $2 $3 $5 $6 $2 $2 $4 $4 Income tax benefits 1 1 3 3 — 1 1 2 — — 1 1 |
Schedule Of Equity-based Compensation Plans Activity | For the nine months ended September 30, 2021, performance shares, performance restricted stock units and restricted stock units were granted to key employees as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards. Weighted Average Grants Grant Date Fair Value Performance shares 73,112 $46.19 Performance restricted stock units 73,112 48.66 Restricted stock units 80,152 48.65 |
IPL [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
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 below (in millions). For IPL and WPL, amounts are for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $2 $3 $8 $8 $1 $1 $3 $3 Interest cost 9 10 26 32 1 2 3 5 Expected return on plan assets (17) (17) (51) (52) (1) (1) (3) (4) Amortization of prior service credit (1) — (1) — — — — — Amortization of actuarial loss 10 9 29 26 1 — 3 2 Settlement losses (a) — — — 4 — — — — $3 $5 $11 $18 $2 $2 $6 $6 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $2 $5 $5 $— $— $1 $1 Interest cost 4 5 12 15 1 1 2 2 Expected return on plan assets (8) (8) (24) (24) (1) (1) (3) (3) Amortization of actuarial loss 5 4 13 11 — — 1 1 $2 $3 $6 $7 $— $— $1 $1 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $1 $3 $3 $1 $— $1 $1 Interest cost 3 5 11 14 — 1 1 2 Expected return on plan assets (8) (8) (23) (23) — (1) — (1) Amortization of actuarial loss 5 4 14 12 1 1 2 2 $1 $2 $5 $6 $2 $1 $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 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Compensation expense $4 $5 $9 $10 $2 $3 $5 $6 $2 $2 $4 $4 Income tax benefits 1 1 3 3 — 1 1 2 — — 1 1 |
Schedule Of Equity-based Compensation Plans Activity | For the nine months ended September 30, 2021, performance shares, performance restricted stock units and restricted stock units were granted to key employees as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards. Weighted Average Grants Grant Date Fair Value Performance shares 73,112 $46.19 Performance restricted stock units 73,112 48.66 Restricted stock units 80,152 48.65 |
WPL [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
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 below (in millions). For IPL and WPL, amounts are for their plan participants covered under plans they sponsor, as well as amounts directly assigned to them related to certain participants in the Alliant Energy and Corporate Services sponsored plans. Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months Alliant Energy 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $2 $3 $8 $8 $1 $1 $3 $3 Interest cost 9 10 26 32 1 2 3 5 Expected return on plan assets (17) (17) (51) (52) (1) (1) (3) (4) Amortization of prior service credit (1) — (1) — — — — — Amortization of actuarial loss 10 9 29 26 1 — 3 2 Settlement losses (a) — — — 4 — — — — $3 $5 $11 $18 $2 $2 $6 $6 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months IPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $2 $5 $5 $— $— $1 $1 Interest cost 4 5 12 15 1 1 2 2 Expected return on plan assets (8) (8) (24) (24) (1) (1) (3) (3) Amortization of actuarial loss 5 4 13 11 — — 1 1 $2 $3 $6 $7 $— $— $1 $1 Defined Benefit Pension Plans OPEB Plans Three Months Nine Months Three Months Nine Months WPL 2021 2020 2021 2020 2021 2020 2021 2020 Service cost $1 $1 $3 $3 $1 $— $1 $1 Interest cost 3 5 11 14 — 1 1 2 Expected return on plan assets (8) (8) (23) (23) — (1) — (1) Amortization of actuarial loss 5 4 14 12 1 1 2 2 $1 $2 $5 $6 $2 $1 $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 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 2021 2020 Compensation expense $4 $5 $9 $10 $2 $3 $5 $6 $2 $2 $4 $4 Income tax benefits 1 1 3 3 — 1 1 2 — — 1 1 |
Schedule Of Equity-based Compensation Plans Activity | For the nine months ended September 30, 2021, performance shares, performance restricted stock units and restricted stock units were granted to key employees as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards. Weighted Average Grants Grant Date Fair Value Performance shares 73,112 $46.19 Performance restricted stock units 73,112 48.66 Restricted stock units 80,152 48.65 |
Asset Retirement Obligations (T
Asset Retirement Obligations (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Schedule of Asset Retirement Obligations [Line Items] | |
Reconciliation of Changes in Asset Retirement Obligations | A reconciliation of the changes in asset retirement obligations associated with long-lived assets for the nine months ended September 30, 2021 is as follows (in millions): Alliant Energy IPL Balance, January 1 $251 $177 Revisions in estimated cash flows 37 32 Liabilities settled (10) (8) Liabilities incurred 1 — Accretion expense 6 4 Balance, September 30 $285 $205 |
IPL [Member] | |
Schedule of Asset Retirement Obligations [Line Items] | |
Reconciliation of Changes in Asset Retirement Obligations | A reconciliation of the changes in asset retirement obligations associated with long-lived assets for the nine months ended September 30, 2021 is as follows (in millions): Alliant Energy IPL Balance, January 1 $251 $177 Revisions in estimated cash flows 37 32 Liabilities settled (10) (8) Liabilities incurred 1 — Accretion expense 6 4 Balance, September 30 $285 $205 |
Derivative Instruments (Tables)
Derivative Instruments (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Derivative Instruments [Line Items] | |
Notional Amounts Of Derivative Instruments | As of September 30, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands): FTRs Natural Gas Coal Diesel Fuel MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 13,265 2021-2022 189,332 2021-2030 4,280 2021-2023 3,654 2021-2022 IPL 4,014 2021-2022 103,859 2021-2030 1,807 2021-2023 — — WPL 9,251 2021-2022 85,473 2021-2030 2,473 2021-2023 3,654 2021-2022 |
Fair Value Of Financial Instruments | Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $158 $24 $72 $20 $86 $4 Non-current derivative assets 78 10 43 9 35 1 Current derivative liabilities 3 9 3 3 — 6 Non-current derivative liabilities 1 16 1 9 — 7 |
IPL [Member] | |
Derivative Instruments [Line Items] | |
Notional Amounts Of Derivative Instruments | As of September 30, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands): FTRs Natural Gas Coal Diesel Fuel MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 13,265 2021-2022 189,332 2021-2030 4,280 2021-2023 3,654 2021-2022 IPL 4,014 2021-2022 103,859 2021-2030 1,807 2021-2023 — — WPL 9,251 2021-2022 85,473 2021-2030 2,473 2021-2023 3,654 2021-2022 |
Fair Value Of Financial Instruments | Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $158 $24 $72 $20 $86 $4 Non-current derivative assets 78 10 43 9 35 1 Current derivative liabilities 3 9 3 3 — 6 Non-current derivative liabilities 1 16 1 9 — 7 |
WPL [Member] | |
Derivative Instruments [Line Items] | |
Notional Amounts Of Derivative Instruments | As of September 30, 2021, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands): FTRs Natural Gas Coal Diesel Fuel MWhs Years Dths Years Tons Years Gallons Years Alliant Energy 13,265 2021-2022 189,332 2021-2030 4,280 2021-2023 3,654 2021-2022 IPL 4,014 2021-2022 103,859 2021-2030 1,807 2021-2023 — — WPL 9,251 2021-2022 85,473 2021-2030 2,473 2021-2023 3,654 2021-2022 |
Fair Value Of Financial Instruments | Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions): Alliant Energy IPL WPL September 30, December 31, September 30, December 31, September 30, December 31, Current derivative assets $158 $24 $72 $20 $86 $4 Non-current derivative assets 78 10 43 9 35 1 Current derivative liabilities 3 9 3 3 — 6 Non-current derivative liabilities 1 16 1 9 — 7 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
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, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 236 — 207 29 236 34 — 5 29 34 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 25 — 25 — 25 Long-term debt (incl. current maturities) 7,075 — 8,083 1 8,084 6,777 — 8,107 2 8,109 IPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 115 — 96 19 115 29 — 3 26 29 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 12 — 12 — 12 Long-term debt 3,347 — 3,849 — 3,849 3,345 — 4,021 — 4,021 WPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $121 $— $111 $10 $121 $5 $— $2 $3 $5 Liabilities: Derivatives — — — — — 13 — 13 — 13 Long-term debt 2,429 — 2,869 — 2,869 2,130 — 2,690 — 2,690 |
Fair Value Measurements Using Significant Unobservable Inputs | Information for Alliant Energy’s and IPL’s fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions). Such amounts for WPL were not material. Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $39 $36 $154 $194 Total net gains included in changes in net assets (realized/unrealized) 5 — — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (7) (5) 10 7 Ending balance, September 30 $29 $30 $164 $201 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 $5 ($1) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $29 $21 $188 $188 Total net gains included in changes in net assets (realized/unrealized) 6 8 — — Transfers out of Level 3 (8) — — — Purchases 21 14 — — Sales — (1) — — Settlements (a) (19) (12) (24) 13 Ending balance, September 30 $29 $30 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $6 $8 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $30 $32 $154 $194 Total net gains (losses) included in changes in net assets (realized/unrealized) 2 (1) — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (5) (4) 10 7 Ending balance, September 30 $19 $26 $164 $201 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 $2 ($1) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $26 $18 $188 $188 Total net gains included in changes in net assets (realized/unrealized) — 7 — — Transfers out of Level 3 (8) — — — Purchases 16 11 — — Sales — (1) — — Settlements (a) (15) (9) (24) 13 Ending balance, September 30 $19 $26 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $— $7 $— $— (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold. |
Fair Value Of Net Derivative Assets | The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2021 $7 $22 $5 $14 $2 $8 December 31, 2020 18 11 17 9 1 2 |
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, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 236 — 207 29 236 34 — 5 29 34 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 25 — 25 — 25 Long-term debt (incl. current maturities) 7,075 — 8,083 1 8,084 6,777 — 8,107 2 8,109 IPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 115 — 96 19 115 29 — 3 26 29 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 12 — 12 — 12 Long-term debt 3,347 — 3,849 — 3,849 3,345 — 4,021 — 4,021 WPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $121 $— $111 $10 $121 $5 $— $2 $3 $5 Liabilities: Derivatives — — — — — 13 — 13 — 13 Long-term debt 2,429 — 2,869 — 2,869 2,130 — 2,690 — 2,690 |
Fair Value Measurements Using Significant Unobservable Inputs | Information for Alliant Energy’s and IPL’s fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions). Such amounts for WPL were not material. Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $39 $36 $154 $194 Total net gains included in changes in net assets (realized/unrealized) 5 — — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (7) (5) 10 7 Ending balance, September 30 $29 $30 $164 $201 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 $5 ($1) $— $— Alliant Energy Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $29 $21 $188 $188 Total net gains included in changes in net assets (realized/unrealized) 6 8 — — Transfers out of Level 3 (8) — — — Purchases 21 14 — — Sales — (1) — — Settlements (a) (19) (12) (24) 13 Ending balance, September 30 $29 $30 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $6 $8 $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Three Months Ended September 30 2021 2020 2021 2020 Beginning balance, July 1 $30 $32 $154 $194 Total net gains (losses) included in changes in net assets (realized/unrealized) 2 (1) — — Transfers out of Level 3 (8) — — — Sales — (1) — — Settlements (a) (5) (4) 10 7 Ending balance, September 30 $19 $26 $164 $201 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 $2 ($1) $— $— IPL Commodity Contract Derivative Assets and (Liabilities), net Deferred Proceeds Nine Months Ended September 30 2021 2020 2021 2020 Beginning balance, January 1 $26 $18 $188 $188 Total net gains included in changes in net assets (realized/unrealized) — 7 — — Transfers out of Level 3 (8) — — — Purchases 16 11 — — Sales — (1) — — Settlements (a) (15) (9) (24) 13 Ending balance, September 30 $19 $26 $164 $201 The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30 $— $7 $— $— (a) Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for expected credit losses associated with the receivables sold and cash amounts received from the receivables sold. |
Fair Value Of Net Derivative Assets | The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2021 $7 $22 $5 $14 $2 $8 December 31, 2020 18 11 17 9 1 2 |
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, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 236 — 207 29 236 34 — 5 29 34 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 25 — 25 — 25 Long-term debt (incl. current maturities) 7,075 — 8,083 1 8,084 6,777 — 8,107 2 8,109 IPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Money market fund investments $9 $9 $— $— $9 $44 $44 $— $— $44 Derivatives 115 — 96 19 115 29 — 3 26 29 Deferred proceeds 164 — — 164 164 188 — — 188 188 Liabilities: Derivatives 4 — 4 — 4 12 — 12 — 12 Long-term debt 3,347 — 3,849 — 3,849 3,345 — 4,021 — 4,021 WPL September 30, 2021 December 31, 2020 Fair Value Fair Value Carrying Level Level Level Carrying Level Level Level Amount 1 2 3 Total Amount 1 2 3 Total Assets: Derivatives $121 $— $111 $10 $121 $5 $— $2 $3 $5 Liabilities: Derivatives — — — — — 13 — 13 — 13 Long-term debt 2,429 — 2,869 — 2,869 2,130 — 2,690 — 2,690 |
Fair Value Of Net Derivative Assets | The fair value of FTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets as follows (in millions): Alliant Energy IPL WPL Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs September 30, 2021 $7 $22 $5 $14 $2 $8 December 31, 2020 18 11 17 9 1 2 |
Commitments And Contingencies (
Commitments And Contingencies (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Commitments and Contingencies [Line Items] | |
Other Purchase Commitments | At September 30, 2021, related minimum future commitments were as follows (in millions): Alliant Energy IPL WPL Natural gas $985 $514 $471 Coal 82 54 28 Other (a) 134 71 39 $1,201 $639 $538 (a) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2021. |
MGP Site Estimated Future Costs And Recorded Liabilities | At September 30, 2021, 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, which are not discounted, were as follows (in millions). At September 30, 2021, such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $9 - $24 $6 - $19 Current and non-current environmental liabilities $12 $9 |
IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Other Purchase Commitments | At September 30, 2021, related minimum future commitments were as follows (in millions): Alliant Energy IPL WPL Natural gas $985 $514 $471 Coal 82 54 28 Other (a) 134 71 39 $1,201 $639 $538 (a) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2021. |
MGP Site Estimated Future Costs And Recorded Liabilities | At September 30, 2021, 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, which are not discounted, were as follows (in millions). At September 30, 2021, such amounts for WPL were not material. Alliant Energy IPL Range of estimated future costs $9 - $24 $6 - $19 Current and non-current environmental liabilities $12 $9 |
WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Other Purchase Commitments | At September 30, 2021, related minimum future commitments were as follows (in millions): Alliant Energy IPL WPL Natural gas $985 $514 $471 Coal 82 54 28 Other (a) 134 71 39 $1,201 $639 $538 (a) Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2021. |
Segments Of Business (Tables)
Segments Of Business (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
Segment Reporting Information [Line Items] | |
Schedule Of Segments Of Business | Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2021 Revenues $939 $50 $13 $1,002 $22 $1,024 Operating income (loss) 290 (5) (5) 280 9 289 Net income attributable to Alliant Energy common shareowners 250 6 256 Three Months Ended September 30, 2020 Revenues $852 $42 $10 $904 $16 $920 Operating income (loss) 251 (1) 1 251 21 272 Net income attributable to Alliant Energy common shareowners 221 25 246 Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2021 Revenues $2,357 $289 $36 $2,682 $60 $2,742 Operating income (loss) 601 42 (4) 639 24 663 Net income attributable to Alliant Energy common shareowners 537 34 571 Nine Months Ended September 30, 2020 Revenues $2,257 $253 $32 $2,542 $57 $2,599 Operating income 549 48 5 602 26 628 Net income attributable to Alliant Energy common shareowners 510 40 550 IPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $555 $31 $13 $599 Operating income (loss) 186 (3) (3) 180 Net income available for common stock 157 Three Months Ended September 30, 2020 Revenues $519 $24 $10 $553 Operating income 159 1 2 162 Net income available for common stock 148 Nine Months Ended September 30, 2021 Revenues $1,343 $165 $35 $1,543 Operating income (loss) 365 30 (1) 394 Net income available for common stock 322 Nine Months Ended September 30, 2020 Revenues $1,332 $141 $31 $1,504 Operating income 308 34 5 347 Net income available for common stock 290 WPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $384 $19 $— $403 Operating income (loss) 104 (2) (2) 100 Net income 93 Three Months Ended September 30, 2020 Revenues $333 $18 $— $351 Operating income (loss) 92 (2) (1) 89 Net income 73 Nine Months Ended September 30, 2021 Revenues $1,014 $124 $1 $1,139 Operating income (loss) 236 12 (3) 245 Net income 215 Nine Months Ended September 30, 2020 Revenues $925 $112 $1 $1,038 Operating income 241 14 — 255 Net income 220 |
IPL [Member] | |
Segment Reporting Information [Line Items] | |
Schedule Of Segments Of Business | Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2021 Revenues $939 $50 $13 $1,002 $22 $1,024 Operating income (loss) 290 (5) (5) 280 9 289 Net income attributable to Alliant Energy common shareowners 250 6 256 Three Months Ended September 30, 2020 Revenues $852 $42 $10 $904 $16 $920 Operating income (loss) 251 (1) 1 251 21 272 Net income attributable to Alliant Energy common shareowners 221 25 246 Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2021 Revenues $2,357 $289 $36 $2,682 $60 $2,742 Operating income (loss) 601 42 (4) 639 24 663 Net income attributable to Alliant Energy common shareowners 537 34 571 Nine Months Ended September 30, 2020 Revenues $2,257 $253 $32 $2,542 $57 $2,599 Operating income 549 48 5 602 26 628 Net income attributable to Alliant Energy common shareowners 510 40 550 IPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $555 $31 $13 $599 Operating income (loss) 186 (3) (3) 180 Net income available for common stock 157 Three Months Ended September 30, 2020 Revenues $519 $24 $10 $553 Operating income 159 1 2 162 Net income available for common stock 148 Nine Months Ended September 30, 2021 Revenues $1,343 $165 $35 $1,543 Operating income (loss) 365 30 (1) 394 Net income available for common stock 322 Nine Months Ended September 30, 2020 Revenues $1,332 $141 $31 $1,504 Operating income 308 34 5 347 Net income available for common stock 290 WPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $384 $19 $— $403 Operating income (loss) 104 (2) (2) 100 Net income 93 Three Months Ended September 30, 2020 Revenues $333 $18 $— $351 Operating income (loss) 92 (2) (1) 89 Net income 73 Nine Months Ended September 30, 2021 Revenues $1,014 $124 $1 $1,139 Operating income (loss) 236 12 (3) 245 Net income 215 Nine Months Ended September 30, 2020 Revenues $925 $112 $1 $1,038 Operating income 241 14 — 255 Net income 220 |
WPL [Member] | |
Segment Reporting Information [Line Items] | |
Schedule Of Segments Of Business | Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations. Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Three Months Ended September 30, 2021 Revenues $939 $50 $13 $1,002 $22 $1,024 Operating income (loss) 290 (5) (5) 280 9 289 Net income attributable to Alliant Energy common shareowners 250 6 256 Three Months Ended September 30, 2020 Revenues $852 $42 $10 $904 $16 $920 Operating income (loss) 251 (1) 1 251 21 272 Net income attributable to Alliant Energy common shareowners 221 25 246 Alliant Energy ATC Holdings, Alliant Utility Non-Utility, Energy Electric Gas Other Total Parent and Other Consolidated (in millions) Nine Months Ended September 30, 2021 Revenues $2,357 $289 $36 $2,682 $60 $2,742 Operating income (loss) 601 42 (4) 639 24 663 Net income attributable to Alliant Energy common shareowners 537 34 571 Nine Months Ended September 30, 2020 Revenues $2,257 $253 $32 $2,542 $57 $2,599 Operating income 549 48 5 602 26 628 Net income attributable to Alliant Energy common shareowners 510 40 550 IPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $555 $31 $13 $599 Operating income (loss) 186 (3) (3) 180 Net income available for common stock 157 Three Months Ended September 30, 2020 Revenues $519 $24 $10 $553 Operating income 159 1 2 162 Net income available for common stock 148 Nine Months Ended September 30, 2021 Revenues $1,343 $165 $35 $1,543 Operating income (loss) 365 30 (1) 394 Net income available for common stock 322 Nine Months Ended September 30, 2020 Revenues $1,332 $141 $31 $1,504 Operating income 308 34 5 347 Net income available for common stock 290 WPL Electric Gas Other Total (in millions) Three Months Ended September 30, 2021 Revenues $384 $19 $— $403 Operating income (loss) 104 (2) (2) 100 Net income 93 Three Months Ended September 30, 2020 Revenues $333 $18 $— $351 Operating income (loss) 92 (2) (1) 89 Net income 73 Nine Months Ended September 30, 2021 Revenues $1,014 $124 $1 $1,139 Operating income (loss) 236 12 (3) 245 Net income 215 Nine Months Ended September 30, 2020 Revenues $925 $112 $1 $1,038 Operating income 241 14 — 255 Net income 220 |
Related Parties (Tables)
Related Parties (Tables) | 9 Months Ended |
Sep. 30, 2021 | |
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 2021 2020 2021 2020 2021 2020 2021 2020 Corporate Services billings $50 $53 $138 $134 $37 $41 $113 $108 Sales credited 4 10 9 35 16 — 23 4 Purchases billed 105 110 347 248 24 39 71 79 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Net payables to Corporate Services $109 $110 $80 $73 |
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 2021 2020 2021 2020 ATC billings to WPL $29 $27 $91 $80 WPL billings to ATC 4 2 13 8 |
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 2021 2020 2021 2020 2021 2020 2021 2020 Corporate Services billings $50 $53 $138 $134 $37 $41 $113 $108 Sales credited 4 10 9 35 16 — 23 4 Purchases billed 105 110 347 248 24 39 71 79 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Net payables to Corporate Services $109 $110 $80 $73 |
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 2021 2020 2021 2020 2021 2020 2021 2020 Corporate Services billings $50 $53 $138 $134 $37 $41 $113 $108 Sales credited 4 10 9 35 16 — 23 4 Purchases billed 105 110 347 248 24 39 71 79 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions): IPL WPL September 30, 2021 December 31, 2020 September 30, 2021 December 31, 2020 Net payables to Corporate Services $109 $110 $80 $73 |
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 2021 2020 2021 2020 ATC billings to WPL $29 $27 $91 $80 WPL billings to ATC 4 2 13 8 |
Summary Of Significant Accoun_3
Summary Of Significant Accounting Policies (Narrative) (Details) $ in Millions | Sep. 30, 2021USD ($) |
WPL [Member] | Columbia Units 1 and 2 [Member] | |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |
Electric plant anticipated to be retired early | $ 470 |
Regulatory Matters (Narrative)
Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
Regulatory Matters [Line Items] | ||
Regulatory assets | $ 2,018 | $ 2,010 |
IPL [Member] | ||
Regulatory Matters [Line Items] | ||
Regulatory assets | 1,507 | 1,483 |
WPL [Member] | ||
Regulatory Matters [Line Items] | ||
Regulatory assets | 511 | $ 527 |
Deferred Fuel Costs | IPL [Member] | ||
Regulatory Matters [Line Items] | ||
Regulatory assets | 15 | |
Deferred Fuel Costs | WPL [Member] | ||
Regulatory Matters [Line Items] | ||
Regulatory assets | $ 12 |
Regulatory Matters (Regulatory
Regulatory Matters (Regulatory Assets) (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
Regulatory Assets [Line Items] | ||
Regulatory assets | $ 2,018 | $ 2,010 |
Tax-related [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 931 | 890 |
Pension and OPEB costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 549 | 580 |
Asset retirement obligations [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 124 | 119 |
Assets retired early [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 98 | 113 |
IPL's DAEC PPA amendment [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 96 | 110 |
WPL's Western Wisconsin gas distribution expansion investments [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 53 | 55 |
Commodity cost recovery [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 32 | 4 |
Derivatives [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 4 | 26 |
Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 131 | 113 |
IPL [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 1,507 | 1,483 |
IPL [Member] | Tax-related [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 881 | 843 |
IPL [Member] | Pension and OPEB costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 276 | 291 |
IPL [Member] | Asset retirement obligations [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 85 | 81 |
IPL [Member] | Assets retired early [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 69 | 77 |
IPL [Member] | IPL's DAEC PPA amendment [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 96 | 110 |
IPL [Member] | Commodity cost recovery [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 17 | 1 |
IPL [Member] | Derivatives [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 4 | 13 |
IPL [Member] | Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 79 | 67 |
WPL [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 511 | 527 |
WPL [Member] | Tax-related [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 50 | 47 |
WPL [Member] | Pension and OPEB costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 273 | 289 |
WPL [Member] | Asset retirement obligations [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 39 | 38 |
WPL [Member] | Assets retired early [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 29 | 36 |
WPL [Member] | WPL's Western Wisconsin gas distribution expansion investments [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 53 | 55 |
WPL [Member] | Commodity cost recovery [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 15 | 3 |
WPL [Member] | Derivatives [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | 0 | 13 |
WPL [Member] | Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory assets | $ 52 | $ 46 |
Regulatory Matters (Regulator_2
Regulatory Matters (Regulatory Liabilities) (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | $ 1,361 | $ 1,306 |
Tax-related [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 611 | 732 |
Cost of removal obligations [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 383 | 367 |
Derivatives [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 221 | 28 |
Electric transmission cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 53 | 68 |
WPL's West Riverside liquidated damages [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 40 | 38 |
Other [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 53 | 73 |
IPL [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 720 | 676 |
IPL [Member] | Tax-related [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 313 | 331 |
IPL [Member] | Cost of removal obligations [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 252 | 238 |
IPL [Member] | Derivatives [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 104 | 25 |
IPL [Member] | Electric transmission cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 29 | 39 |
IPL [Member] | Other [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 22 | 43 |
WPL [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 641 | 630 |
WPL [Member] | Tax-related [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 298 | 401 |
WPL [Member] | Cost of removal obligations [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 131 | 129 |
WPL [Member] | Derivatives [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 117 | 3 |
WPL [Member] | Electric transmission cost recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 24 | 29 |
WPL [Member] | WPL's West Riverside liquidated damages [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 40 | 38 |
WPL [Member] | Other [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | $ 31 | $ 30 |
Receivables (Narrative) (Detail
Receivables (Narrative) (Details) - IPL [Member] $ in Millions | Sep. 30, 2021USD ($) |
Receivables [Line Items] | |
Limit on cash proceeds to be received from third-party | $ 110 |
Receivables Sold [Member] | |
Receivables [Line Items] | |
Available capacity | 60 |
Receivables Sold [Member] | Financial Asset, Past Due | |
Receivables [Line Items] | |
Outstanding receivables past due | $ 19 |
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, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Maximum [Member] | ||||
Receivables [Line Items] | ||||
Maximum outstanding aggregate cash proceeds (based on daily outstanding balances) | $ 110 | $ 1 | $ 110 | $ 96 |
Average [Member] | ||||
Receivables [Line Items] | ||||
Average outstanding aggregate cash proceeds (based on daily outstanding balances) | $ 65 | $ 1 | $ 52 | $ 12 |
Receivables (Receivables Sold U
Receivables (Receivables Sold Under The Agreement) (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
Receivables [Line Items] | ||
Fair value of deferred proceeds | $ 164 | $ 188 |
IPL [Member] | ||
Receivables [Line Items] | ||
Fair value of deferred proceeds | 164 | 188 |
Receivables Sold [Member] | IPL [Member] | ||
Receivables [Line Items] | ||
Customer accounts receivable | 145 | 114 |
Unbilled utility revenues | 83 | 92 |
Receivables sold to third party | 228 | 206 |
Less: cash proceeds | 50 | 1 |
Deferred proceeds | 178 | 205 |
Less: allowance for expected credit losses | 14 | 17 |
Fair value of deferred proceeds | $ 164 | $ 188 |
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, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Receivables [Line Items] | ||||
Collections | $ 607 | $ 561 | $ 1,589 | $ 1,555 |
Write-offs, net of recoveries | $ 4 | $ 1 | $ 7 | $ 4 |
Investments (Unconsolidated Equ
Investments (Unconsolidated Equity Investments) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Schedule of Equity Method Investments [Line Items] | ||||
Equity income from unconsolidated investments, net | $ (13) | $ (15) | $ (47) | $ (46) |
ATC Holdings [Member] | ||||
Schedule of Equity Method Investments [Line Items] | ||||
Equity income from unconsolidated investments, net | (12) | (11) | (34) | (36) |
Other [Member] | ||||
Schedule of Equity Method Investments [Line Items] | ||||
Equity income from unconsolidated investments, net | $ (1) | $ (4) | $ (13) | $ (10) |
Common Equity (Common Share Act
Common Equity (Common Share Activity) (Details) | 9 Months Ended |
Sep. 30, 2021shares | |
Common Stock Oustanding [Roll Forward] | |
Shares outstanding, January 1, 2021 (in shares) | 249,868,415 |
Shareowner Direct Plan (in shares) | 378,823 |
Equity-based compensation plans (in shares) | 113,549 |
Shares outstanding, September 30, 2021 (in shares) | 250,360,787 |
Common Equity (Changes in Share
Common Equity (Changes in Shareowners' Equity) (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | 9 Months Ended | ||||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | |
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | $ 5,688 | |||||
Beginning balance | $ 6,019 | $ 5,748 | 5,888 | $ 5,405 | ||
Net income attributable to common shareowners | 256 | 246 | 571 | 550 | ||
Net income | 259 | 249 | 579 | 558 | ||
Common stock dividends | (101) | (94) | (304) | (281) | ||
Equity forward settlements and Shareowner Direct Plan issuances | 6 | 6 | 22 | 241 | ||
Equity-based compensation plans and other | 5 | 3 | 8 | 5 | ||
Adoption of new accounting standard, net of tax | (3,261) | (3,261) | $ (2,994) | |||
Other comprehensive loss, net of tax | (2) | |||||
Ending balance | 5,985 | 5,985 | ||||
Ending balance | $ 6,185 | $ 5,909 | $ 6,185 | $ 5,909 | ||
Common stock dividends (in dollars per share) | $ 0.4025 | $ 0.38 | $ 1.2075 | $ 1.14 | ||
Common Stock [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | $ 3 | $ 2 | $ 2 | $ 2 | ||
Equity forward settlements and Shareowner Direct Plan issuances | 1 | |||||
Ending balance | 3 | 2 | 3 | 2 | ||
Additional Paid-in Capital [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 2,722 | 2,683 | 2,704 | 2,446 | ||
Equity forward settlements and Shareowner Direct Plan issuances | 6 | 6 | 21 | 241 | ||
Equity-based compensation plans and other | 5 | 4 | 8 | 6 | ||
Ending balance | 2,733 | 2,693 | 2,733 | 2,693 | ||
Retained Earnings [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 3,106 | 2,874 | 2,994 | 2,766 | ||
Net income attributable to common shareowners | 256 | 246 | 571 | 550 | ||
Common stock dividends | (101) | (94) | (304) | (281) | ||
Ending balance | 3,261 | 3,026 | 3,261 | 3,026 | ||
Accumulated Other Comprehensive Income (Loss) [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | (1) | (1) | (1) | 1 | ||
Other comprehensive loss, net of tax | (2) | |||||
Ending balance | (1) | (1) | (1) | (1) | ||
Shares in Deferred Compensation Trust [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | (11) | (10) | (11) | (10) | ||
Equity-based compensation plans and other | (1) | (1) | ||||
Ending balance | (11) | (11) | (11) | (11) | ||
Cumulative Preferred Stock [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 200 | 200 | 200 | 200 | ||
Ending balance | 200 | 200 | 200 | 200 | ||
IPL [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 3,764 | |||||
Beginning balance | 3,979 | 3,671 | 3,964 | 3,472 | ||
Net income attributable to common shareowners | 157 | 148 | 322 | 290 | ||
Net income | 160 | 151 | 330 | 298 | ||
Common stock dividends | (101) | (59) | (301) | (177) | ||
Adoption of new accounting standard, net of tax | (1,000) | (1,000) | (979) | |||
Capital contributions from parent | 170 | 50 | 345 | |||
Ending balance | 3,835 | 3,835 | ||||
Ending balance | 4,035 | 3,930 | 4,035 | 3,930 | ||
IPL [Member] | Common Stock [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 33 | 33 | 33 | 33 | ||
Ending balance | 33 | 33 | 33 | 33 | ||
IPL [Member] | Additional Paid-in Capital [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 2,802 | 2,523 | 2,752 | 2,348 | ||
Capital contributions from parent | 170 | 50 | 345 | |||
Ending balance | 2,802 | 2,693 | 2,802 | 2,693 | ||
IPL [Member] | Retained Earnings [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 944 | 915 | 979 | 891 | ||
Net income attributable to common shareowners | 157 | 148 | 322 | 290 | ||
Common stock dividends | (101) | (59) | (301) | (177) | ||
Ending balance | 1,000 | 1,004 | 1,000 | 1,004 | ||
IPL [Member] | Cumulative Preferred Stock [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 200 | 200 | 200 | 200 | ||
Ending balance | 200 | 200 | 200 | 200 | ||
WPL [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 2,478 | |||||
Beginning balance | 2,725 | 2,452 | 2,478 | 2,364 | ||
Net income | 93 | 73 | 215 | 220 | ||
Common stock dividends | (41) | (43) | (126) | (127) | ||
Adoption of new accounting standard, net of tax | (1,042) | (1,042) | $ (953) | |||
Capital contributions from parent | 35 | 245 | 25 | |||
Ending balance | 2,812 | 2,812 | ||||
Ending balance | 2,812 | 2,482 | 2,812 | 2,482 | ||
WPL [Member] | Common Stock [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 66 | 66 | 66 | 66 | ||
Ending balance | 66 | 66 | 66 | 66 | ||
WPL [Member] | Additional Paid-in Capital [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 1,669 | 1,459 | 1,459 | 1,434 | ||
Capital contributions from parent | 35 | 245 | 25 | |||
Ending balance | 1,704 | 1,459 | 1,704 | 1,459 | ||
WPL [Member] | Retained Earnings [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Beginning balance | 990 | 927 | 953 | 864 | ||
Net income | 93 | 73 | 215 | 220 | ||
Common stock dividends | (41) | (43) | (126) | (127) | ||
Ending balance | $ 1,042 | $ 957 | $ 1,042 | $ 957 | ||
Credit Losses ASU [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Adoption of new accounting standard, net of tax | $ (9) | |||||
Credit Losses ASU [Member] | Retained Earnings [Member] | ||||||
Changes in Shareowners' Equity Roll Forward [Line Items] | ||||||
Adoption of new accounting standard, net of tax | $ (9) |
Preferred Stock (Narrative) (De
Preferred Stock (Narrative) (Details) - IPL [Member] $ in Millions | 9 Months Ended |
Sep. 30, 2021USD ($)shares | |
Class of Stock [Line Items] | |
Preferred shares outstanding (in shares) | shares | 8,000,000 |
Preferred stock series, percent | 5.10% |
Cumulative preferred stock | $ | $ 200 |
Debt (Narrative) (Details)
Debt (Narrative) (Details) $ in Millions | Sep. 30, 2021USD ($) |
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 | 500 |
IPL [Member] | |
Debt [Line Items] | |
Line of credit facility, current borrowing capacity | 100 |
WPL [Member] | |
Debt [Line Items] | |
Line of credit facility, current borrowing capacity | 400 |
Debentures | 1.95% debenture, due 2031 | WPL [Member] | |
Debt [Line Items] | |
Long-term debt | $ 300 |
Interest rate, percent | 1.95% |
Debt (Credit Facilities) (Detai
Debt (Credit Facilities) (Details) $ in Millions | Sep. 30, 2021USD ($) |
Debt [Line Items] | |
Amount outstanding | $ 316 |
Weighted average interest rates | 0.20% |
Available credit facility capacity | $ 684 |
IPL [Member] | |
Debt [Line Items] | |
Amount outstanding | 0 |
Available credit facility capacity | 100 |
WPL [Member] | |
Debt [Line Items] | |
Amount outstanding | $ 3 |
Weighted average interest rates | 0.10% |
Available credit facility capacity | $ 397 |
Debt (Other Short-Term Borrowin
Debt (Other Short-Term Borrowings) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Debt [Line Items] | ||||
Maximum amount outstanding (based on daily outstanding balances) | $ 648 | $ 422 | $ 648 | $ 463 |
Average amount outstanding (based on daily outstanding balances) | $ 560 | $ 252 | $ 479 | $ 252 |
Weighted average interest rates | 0.20% | 0.20% | 0.20% | 1.10% |
IPL [Member] | ||||
Debt [Line Items] | ||||
Maximum amount outstanding (based on daily outstanding balances) | $ 8 | $ 0 | $ 19 | $ 8 |
Average amount outstanding (based on daily outstanding balances) | $ 0 | 0 | $ 0 | $ 0 |
Weighted average interest rates | 0.20% | 0.20% | 0.50% | |
WPL [Member] | ||||
Debt [Line Items] | ||||
Maximum amount outstanding (based on daily outstanding balances) | $ 320 | 139 | $ 320 | $ 212 |
Average amount outstanding (based on daily outstanding balances) | $ 221 | $ 83 | $ 196 | $ 86 |
Weighted average interest rates | 0.10% | 0.20% | 0.10% | 1.20% |
Revenue (Disaggregation of Reve
Revenue (Disaggregation of Revenues) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | $ 1,024 | $ 920 | $ 2,742 | $ 2,599 |
Electric [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 939 | 852 | 2,357 | 2,257 |
Electric [Member] | Retail - residential [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 348 | 328 | 868 | 845 |
Electric [Member] | Retail - commercial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 232 | 210 | 579 | 556 |
Electric [Member] | Retail - industrial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 265 | 241 | 677 | 648 |
Electric [Member] | Wholesale [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 55 | 47 | 142 | 127 |
Electric [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 39 | 26 | 91 | 81 |
Gas [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 50 | 42 | 289 | 253 |
Gas [Member] | Retail - residential [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 24 | 22 | 162 | 146 |
Gas [Member] | Retail - commercial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 13 | 10 | 85 | 70 |
Gas [Member] | Retail - industrial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 3 | 2 | 11 | 8 |
Gas [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 10 | 8 | 31 | 29 |
Other Utility [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 13 | 10 | 36 | 32 |
Other Utility [Member] | Steam [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 9 | 8 | 27 | 27 |
Other Utility [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 4 | 2 | 9 | 5 |
Non-utility and Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 22 | 16 | 60 | 57 |
Non-utility and Other [Member] | Travero and other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 22 | 16 | 60 | 57 |
IPL [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 599 | 553 | 1,543 | 1,504 |
IPL [Member] | Electric [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 555 | 519 | 1,343 | 1,332 |
IPL [Member] | Electric [Member] | Retail - residential [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 207 | 189 | 488 | 472 |
IPL [Member] | Electric [Member] | Retail - commercial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 160 | 142 | 385 | 371 |
IPL [Member] | Electric [Member] | Retail - industrial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 158 | 149 | 386 | 384 |
IPL [Member] | Electric [Member] | Wholesale [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 18 | 17 | 44 | 44 |
IPL [Member] | Electric [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 12 | 22 | 40 | 61 |
IPL [Member] | Gas [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 31 | 24 | 165 | 141 |
IPL [Member] | Gas [Member] | Retail - residential [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 14 | 12 | 90 | 79 |
IPL [Member] | Gas [Member] | Retail - commercial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 8 | 6 | 47 | 38 |
IPL [Member] | Gas [Member] | Retail - industrial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 3 | 1 | 8 | 5 |
IPL [Member] | Gas [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 6 | 5 | 20 | 19 |
IPL [Member] | Other Utility [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 13 | 10 | 35 | 31 |
IPL [Member] | Other Utility [Member] | Steam [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 9 | 8 | 27 | 27 |
IPL [Member] | Other Utility [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 4 | 2 | 8 | 4 |
WPL [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 403 | 351 | 1,139 | 1,038 |
WPL [Member] | Electric [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 384 | 333 | 1,014 | 925 |
WPL [Member] | Electric [Member] | Retail - residential [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 141 | 139 | 380 | 373 |
WPL [Member] | Electric [Member] | Retail - commercial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 72 | 68 | 194 | 185 |
WPL [Member] | Electric [Member] | Retail - industrial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 107 | 92 | 291 | 264 |
WPL [Member] | Electric [Member] | Wholesale [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 37 | 30 | 98 | 83 |
WPL [Member] | Electric [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 27 | 4 | 51 | 20 |
WPL [Member] | Gas [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 19 | 18 | 124 | 112 |
WPL [Member] | Gas [Member] | Retail - residential [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 10 | 10 | 72 | 67 |
WPL [Member] | Gas [Member] | Retail - commercial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 5 | 4 | 38 | 32 |
WPL [Member] | Gas [Member] | Retail - industrial [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 0 | 1 | 3 | 3 |
WPL [Member] | Gas [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 4 | 3 | 11 | 10 |
WPL [Member] | Other Utility [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | 0 | 0 | 1 | 1 |
WPL [Member] | Other Utility [Member] | Other [Member] | ||||
Disaggregation of Revenue [Line Items] | ||||
Revenue from contracts with customers | $ 0 | $ 0 | $ 1 | $ 1 |
Income Taxes (Schedule Of Effec
Income Taxes (Schedule Of Effective Income Tax Rates) (Details) | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Effective Tax Rate [Line Items] | ||||
Overall income tax rate | (9.00%) | (9.00%) | (13.00%) | (9.00%) |
IPL [Member] | ||||
Effective Tax Rate [Line Items] | ||||
Overall income tax rate | (8.00%) | (14.00%) | (11.00%) | (14.00%) |
WPL [Member] | ||||
Effective Tax Rate [Line Items] | ||||
Overall income tax rate | (19.00%) | (7.00%) | (24.00%) | (8.00%) |
Income Taxes (Summary Of Tax Cr
Income Taxes (Summary Of Tax Credit Carryforwards) (Details) $ in Millions | Sep. 30, 2021USD ($) |
Federal [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | $ 170 |
Tax credits, carryforward amount | 547 |
Federal [Member] | IPL [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 157 |
Tax credits, carryforward amount | 339 |
Federal [Member] | WPL [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 1 |
Tax credits, carryforward amount | 186 |
State [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 592 |
State [Member] | IPL [Member] | |
Carryforwards [Line Items] | |
Net operating losses, carryforward amount | 24 |
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, 2021USD ($)shares | |
Defined Benefit Plan Disclosure [Line Items] | |
Unrecognized compensation cost | $ 7 |
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 |
WPL [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Unrecognized compensation cost | $ 3 |
Omnibus Incentive Plan [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Shares included in diluted earnings per share (in shares) | shares | 491,406 |
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, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Defined benefit pension plans [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Service cost | $ 2 | $ 3 | $ 8 | $ 8 |
Interest cost | 9 | 10 | 26 | 32 |
Expected return on plan assets | (17) | (17) | (51) | (52) |
Amortization of prior service credit | (1) | 0 | (1) | 0 |
Amortization of actuarial loss | 10 | 9 | 29 | 26 |
Settlement losses | 0 | 0 | 0 | 4 |
Total | 3 | 5 | 11 | 18 |
OPEB Plans [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Service cost | 1 | 1 | 3 | 3 |
Interest cost | 1 | 2 | 3 | 5 |
Expected return on plan assets | (1) | (1) | (3) | (4) |
Amortization of prior service credit | 0 | 0 | 0 | 0 |
Amortization of actuarial loss | 1 | 0 | 3 | 2 |
Settlement losses | 0 | 0 | 0 | 0 |
Total | 2 | 2 | 6 | 6 |
IPL [Member] | Defined benefit pension plans [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Service cost | 1 | 2 | 5 | 5 |
Interest cost | 4 | 5 | 12 | 15 |
Expected return on plan assets | (8) | (8) | (24) | (24) |
Amortization of actuarial loss | 5 | 4 | 13 | 11 |
Total | 2 | 3 | 6 | 7 |
IPL [Member] | OPEB Plans [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Service cost | 0 | 0 | 1 | 1 |
Interest cost | 1 | 1 | 2 | 2 |
Expected return on plan assets | (1) | (1) | (3) | (3) |
Amortization of actuarial loss | 0 | 0 | 1 | 1 |
Total | 0 | 0 | 1 | 1 |
WPL [Member] | Defined benefit pension plans [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Service cost | 1 | 1 | 3 | 3 |
Interest cost | 3 | 5 | 11 | 14 |
Expected return on plan assets | (8) | (8) | (23) | (23) |
Amortization of actuarial loss | 5 | 4 | 14 | 12 |
Total | 1 | 2 | 5 | 6 |
WPL [Member] | OPEB Plans [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Service cost | 1 | 0 | 1 | 1 |
Interest cost | 0 | 1 | 1 | 2 |
Expected return on plan assets | 0 | (1) | 0 | (1) |
Amortization of actuarial loss | 1 | 1 | 2 | 2 |
Total | $ 2 | $ 1 | $ 4 | $ 4 |
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, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Compensation expense | $ 4 | $ 5 | $ 9 | $ 10 |
Income tax benefits | 1 | 1 | 3 | 3 |
IPL [Member] | ||||
Compensation expense | 2 | 3 | 5 | 6 |
Income tax benefits | 0 | 1 | 1 | 2 |
WPL [Member] | ||||
Compensation expense | 2 | 2 | 4 | 4 |
Income tax benefits | $ 0 | $ 0 | $ 1 | $ 1 |
Benefit Plans (Summary Of Equit
Benefit Plans (Summary Of Equity-based Compensation Plans Grants) (Details) | 9 Months Ended |
Sep. 30, 2021$ / sharesshares | |
Performance Shares [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Grants (in shares/units) | shares | 73,112 |
Weighted average grant date fair value (in dollars per share/unit) | $ / shares | $ 46.19 |
Performance Restricted Stock Units [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Grants (in shares/units) | shares | 73,112 |
Weighted average grant date fair value (in dollars per share/unit) | $ / shares | $ 48.66 |
Restricted Stock Units [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Grants (in shares/units) | shares | 80,152 |
Weighted average grant date fair value (in dollars per share/unit) | $ / shares | $ 48.65 |
Asset Retirement Obligations (R
Asset Retirement Obligations (Reconciliation Of Changes In Asset Retirement Obligations) (Details) $ in Millions | 9 Months Ended |
Sep. 30, 2021USD ($) | |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | |
Balance, January 1 | $ 251 |
Revisions in estimated cash flows | 37 |
Liabilities settled | (10) |
Liabilities incurred | 1 |
Accretion expense | 6 |
Balance, September 30 | 285 |
IPL [Member] | |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | |
Balance, January 1 | 177 |
Revisions in estimated cash flows | 32 |
Liabilities settled | (8) |
Liabilities incurred | 0 |
Accretion expense | 4 |
Balance, September 30 | $ 205 |
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, 2021DekathermsMWhTgal | |
FTRs (MWhs) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | MWh | 13,265 |
FTRs (MWhs) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | MWh | 4,014 |
FTRs (MWhs) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in MWhs) | MWh | 9,251 |
Natural Gas (Dths) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Dths) | Dekatherms | 189,332 |
Natural Gas (Dths) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Dths) | Dekatherms | 103,859 |
Natural Gas (Dths) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Dths) | Dekatherms | 85,473 |
Coal (Tons) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Tons) | T | 4,280 |
Coal (Tons) [Member] | IPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Tons) | T | 1,807 |
Coal (Tons) [Member] | WPL [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Tons) | T | 2,473 |
Diesel Fuel (Gallons) [Member] | |
Notional Amount of Derivatives [Line Items] | |
Notional unit amount of derivatives (in Gallons) | gal | 3,654 |
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 | 3,654 |
Derivative Instruments (Fair Va
Derivative Instruments (Fair Value Of Financial Instruments) (Details) - Commodity Contracts [Member] - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
Derivatives, Fair Value [Line Items] | ||
Current derivative assets | $ 158 | $ 24 |
Non-current derivative assets | 78 | 10 |
Current derivative liabilities | 3 | 9 |
Non-current derivative liabilities | 1 | 16 |
IPL [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Current derivative assets | 72 | 20 |
Non-current derivative assets | 43 | 9 |
Current derivative liabilities | 3 | 3 |
Non-current derivative liabilities | 1 | 9 |
WPL [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Current derivative assets | 86 | 4 |
Non-current derivative assets | 35 | 1 |
Current derivative liabilities | 0 | 6 |
Non-current derivative liabilities | $ 0 | $ 7 |
Fair Value Measurements (Fair V
Fair Value Measurements (Fair Value Measurements) (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
Assets: | ||
Money market fund investments | $ 9 | $ 44 |
Deferred proceeds | 164 | 188 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 8,084 | 8,109 |
IPL [Member] | ||
Assets: | ||
Money market fund investments | 9 | 44 |
Deferred proceeds | 164 | 188 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 3,849 | 4,021 |
WPL [Member] | ||
Liabilities: | ||
Long-term debt (incl. current maturities) | 2,869 | 2,690 |
Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 236 | 34 |
Liabilities: | ||
Derivatives | 4 | 25 |
Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 115 | 29 |
Liabilities: | ||
Derivatives | 4 | 12 |
Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 121 | 5 |
Liabilities: | ||
Derivatives | 0 | 13 |
Level 1 [Member] | ||
Assets: | ||
Money market fund investments | 9 | 44 |
Deferred proceeds | 0 | 0 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Level 1 [Member] | IPL [Member] | ||
Assets: | ||
Money market fund investments | 9 | 44 |
Deferred proceeds | 0 | 0 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Level 1 [Member] | WPL [Member] | ||
Liabilities: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Level 1 [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 0 | 0 |
Liabilities: | ||
Derivatives | 0 | 0 |
Level 1 [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 0 | 0 |
Liabilities: | ||
Derivatives | 0 | 0 |
Level 1 [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 0 | 0 |
Liabilities: | ||
Derivatives | 0 | 0 |
Level 2 [Member] | ||
Assets: | ||
Money market fund investments | 0 | 0 |
Deferred proceeds | 0 | 0 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 8,083 | 8,107 |
Level 2 [Member] | IPL [Member] | ||
Assets: | ||
Money market fund investments | 0 | 0 |
Deferred proceeds | 0 | 0 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 3,849 | 4,021 |
Level 2 [Member] | WPL [Member] | ||
Liabilities: | ||
Long-term debt (incl. current maturities) | 2,869 | 2,690 |
Level 2 [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 207 | 5 |
Liabilities: | ||
Derivatives | 4 | 25 |
Level 2 [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 96 | 3 |
Liabilities: | ||
Derivatives | 4 | 12 |
Level 2 [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 111 | 2 |
Liabilities: | ||
Derivatives | 0 | 13 |
Level 3 [Member] | ||
Assets: | ||
Money market fund investments | 0 | 0 |
Deferred proceeds | 164 | 188 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 1 | 2 |
Level 3 [Member] | IPL [Member] | ||
Assets: | ||
Money market fund investments | 0 | 0 |
Deferred proceeds | 164 | 188 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Level 3 [Member] | WPL [Member] | ||
Liabilities: | ||
Long-term debt (incl. current maturities) | 0 | 0 |
Level 3 [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 29 | 29 |
Liabilities: | ||
Derivatives | 0 | 0 |
Level 3 [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 19 | 26 |
Liabilities: | ||
Derivatives | 0 | 0 |
Level 3 [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 10 | 3 |
Liabilities: | ||
Derivatives | 0 | 0 |
Carrying Amount [Member] | ||
Assets: | ||
Money market fund investments | 9 | 44 |
Deferred proceeds | 164 | 188 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 7,075 | 6,777 |
Carrying Amount [Member] | IPL [Member] | ||
Assets: | ||
Money market fund investments | 9 | 44 |
Deferred proceeds | 164 | 188 |
Liabilities: | ||
Long-term debt (incl. current maturities) | 3,347 | 3,345 |
Carrying Amount [Member] | WPL [Member] | ||
Liabilities: | ||
Long-term debt (incl. current maturities) | 2,429 | 2,130 |
Carrying Amount [Member] | Commodity Contracts [Member] | ||
Assets: | ||
Derivatives | 236 | 34 |
Liabilities: | ||
Derivatives | 4 | 25 |
Carrying Amount [Member] | Commodity Contracts [Member] | IPL [Member] | ||
Assets: | ||
Derivatives | 115 | 29 |
Liabilities: | ||
Derivatives | 4 | 12 |
Carrying Amount [Member] | Commodity Contracts [Member] | WPL [Member] | ||
Assets: | ||
Derivatives | 121 | 5 |
Liabilities: | ||
Derivatives | $ 0 | $ 13 |
Fair Value Measurements (Fair_2
Fair Value Measurements (Fair Value Measurements Using Significant Unobservable Inputs) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Commodity Contracts [Member] | ||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Beginning balance | $ 39 | $ 36 | $ 29 | $ 21 |
Total net gains (losses) included in changes in net assets (realized/unrealized) | 5 | 0 | 6 | 8 |
Transfers out of Level 3 | (8) | 0 | (8) | 0 |
Purchases | 21 | 14 | ||
Sales | 0 | (1) | 0 | (1) |
Settlements | (7) | (5) | (19) | (12) |
Ending balance | 29 | 30 | 29 | 30 |
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 | 5 | (1) | 6 | 8 |
Commodity Contracts [Member] | IPL [Member] | ||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Beginning balance | 30 | 32 | 26 | 18 |
Total net gains (losses) included in changes in net assets (realized/unrealized) | 2 | (1) | 0 | 7 |
Transfers out of Level 3 | (8) | 0 | (8) | 0 |
Purchases | 16 | 11 | ||
Sales | 0 | (1) | 0 | (1) |
Settlements | (5) | (4) | (15) | (9) |
Ending balance | 19 | 26 | 19 | 26 |
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 | 2 | (1) | 0 | 7 |
Deferred Proceeds [Member] | ||||
Fair Value, Assets and Liabilities, Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Beginning balance | 154 | 194 | 188 | 188 |
Total net gains (losses) included in changes in net assets (realized/unrealized) | 0 | 0 | 0 | 0 |
Transfers out of Level 3 | 0 | 0 | 0 | 0 |
Purchases | 0 | 0 | ||
Sales | 0 | 0 | 0 | 0 |
Settlements | 10 | 7 | (24) | 13 |
Ending balance | 164 | 201 | 164 | 201 |
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 | 154 | 194 | 188 | 188 |
Total net gains (losses) included in changes in net assets (realized/unrealized) | 0 | 0 | 0 | 0 |
Transfers out of Level 3 | 0 | 0 | 0 | 0 |
Purchases | 0 | 0 | ||
Sales | 0 | 0 | 0 | 0 |
Settlements | 10 | 7 | (24) | 13 |
Ending balance | 164 | 201 | 164 | 201 |
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 |
Fair Value Measurements (Fair_3
Fair Value Measurements (Fair Value Of Net Derivative Assets (Liabilities)) (Details) - Commodity Contracts [Member] - USD ($) $ in Millions | Sep. 30, 2021 | Jun. 30, 2021 | Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Dec. 31, 2019 |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | $ 29 | $ 39 | $ 29 | $ 30 | $ 36 | $ 21 |
Excluding Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 7 | 18 | ||||
Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 22 | 11 | ||||
IPL [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 19 | $ 30 | 26 | $ 26 | $ 32 | $ 18 |
IPL [Member] | Excluding Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 5 | 17 | ||||
IPL [Member] | Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 14 | 9 | ||||
WPL [Member] | Excluding Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | 2 | 1 | ||||
WPL [Member] | Financial Transmission Rights [Member] | ||||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||||||
Fair value, net derivative assets | $ 8 | $ 2 |
Commitments And Contingencies_2
Commitments And Contingencies (Narrative) (Details) $ in Millions | 9 Months Ended |
Sep. 30, 2021USD ($) | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | $ 1,201 |
IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 639 |
WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 538 |
Capital Purchase Commitment [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 95 |
Capital Purchase Commitment [Member] | WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 93 |
Indemnification Agreement [Member] | |
Commitments and Contingencies [Line Items] | |
Obligations, maximum | 67 |
Indemnification Agreement [Member] | Purchased Power [Member] | |
Commitments and Contingencies [Line Items] | |
Obligations, maximum | $ 17 |
Whiting Petroleum Affiliate [Member] | |
Commitments and Contingencies [Line Items] | |
Partnership share, percent | 6.00% |
Obligations, maximum | $ 68 |
Credit loss liability | $ 5 |
Commitments And Contingencies_3
Commitments And Contingencies (Other Purchase Commitments) (Details) $ in Millions | 9 Months Ended |
Sep. 30, 2021USD ($) | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | $ 1,201 |
Individual commitments incurred | 1 |
IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 639 |
Individual commitments incurred | 1 |
WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 538 |
Individual commitments incurred | 1 |
Natural gas [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 985 |
Natural gas [Member] | IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 514 |
Natural gas [Member] | WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 471 |
Coal [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 82 |
Coal [Member] | IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 54 |
Coal [Member] | WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 28 |
Other [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 134 |
Other [Member] | IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | 71 |
Other [Member] | WPL [Member] | |
Commitments and Contingencies [Line Items] | |
Minimum future commitments | $ 39 |
Commitments And Contingencies_4
Commitments And Contingencies (MPG Site Estimated Future Costs And Recorded Liabilities) (Details) - Natural Gas Processing Plant [Member] $ in Millions | 9 Months Ended |
Sep. 30, 2021USD ($) | |
Commitments and Contingencies [Line Items] | |
Current and non-current environmental liabilities | $ 12 |
IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Current and non-current environmental liabilities | 9 |
Minimum [Member] | |
Commitments and Contingencies [Line Items] | |
Range of estimated future costs | 9 |
Minimum [Member] | IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Range of estimated future costs | 6 |
Maximum [Member] | |
Commitments and Contingencies [Line Items] | |
Range of estimated future costs | 24 |
Maximum [Member] | IPL [Member] | |
Commitments and Contingencies [Line Items] | |
Range of estimated future costs | $ 19 |
Segments Of Business (Schedule
Segments Of Business (Schedule Of Segments Of Business) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Segment Reporting Information [Line Items] | ||||
Revenues | $ 1,024 | $ 920 | $ 2,742 | $ 2,599 |
Operating income (loss) | 289 | 272 | 663 | 628 |
Net income attributable to common shareowners | 256 | 246 | 571 | 550 |
Net income | 259 | 249 | 579 | 558 |
IPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 599 | 553 | 1,543 | 1,504 |
Operating income (loss) | 180 | 162 | 394 | 347 |
Net income attributable to common shareowners | 157 | 148 | 322 | 290 |
Net income | 160 | 151 | 330 | 298 |
WPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 403 | 351 | 1,139 | 1,038 |
Operating income (loss) | 100 | 89 | 245 | 255 |
Net income | 93 | 73 | 215 | 220 |
Electric [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 939 | 852 | 2,357 | 2,257 |
Operating income (loss) | 290 | 251 | 601 | 549 |
Electric [Member] | IPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 555 | 519 | 1,343 | 1,332 |
Operating income (loss) | 186 | 159 | 365 | 308 |
Electric [Member] | WPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 384 | 333 | 1,014 | 925 |
Operating income (loss) | 104 | 92 | 236 | 241 |
Gas [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 50 | 42 | 289 | 253 |
Operating income (loss) | (5) | (1) | 42 | 48 |
Gas [Member] | IPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 31 | 24 | 165 | 141 |
Operating income (loss) | (3) | 1 | 30 | 34 |
Gas [Member] | WPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 19 | 18 | 124 | 112 |
Operating income (loss) | (2) | (2) | 12 | 14 |
Other Utility [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 13 | 10 | 36 | 32 |
Operating income (loss) | (5) | 1 | (4) | 5 |
Other Utility [Member] | IPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 13 | 10 | 35 | 31 |
Operating income (loss) | (3) | 2 | (1) | 5 |
Other Utility [Member] | WPL [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 0 | 0 | 1 | 1 |
Operating income (loss) | (2) | (1) | (3) | 0 |
Utility Business [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 1,002 | 904 | 2,682 | 2,542 |
Operating income (loss) | 280 | 251 | 639 | 602 |
Net income attributable to common shareowners | 250 | 221 | 537 | 510 |
Non-Utility [Member] | ATC Holdings, Non-Utility, Parent and Other [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Revenues | 22 | 16 | 60 | 57 |
Operating income (loss) | 9 | 21 | 24 | 26 |
Net income attributable to common shareowners | $ 6 | $ 25 | $ 34 | $ 40 |
Related Parties (Narrative) (De
Related Parties (Narrative) (Details) - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
ATC LLC [Member] | WPL Owed ATC LLC [Member] | Equity Method Investee [Member] | ||
Related Party Transactions [Line Items] | ||
Net amounts owed | $ 8 | $ 9 |
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, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
Corporate Services Billings [Member] | IPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 50 | $ 53 | $ 138 | $ 134 |
Corporate Services Billings [Member] | WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 37 | 41 | 113 | 108 |
Sales Credited [Member] | IPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 4 | 10 | 9 | 35 |
Sales Credited [Member] | WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 16 | 0 | 23 | 4 |
Purchases Billed [Member] | IPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | 105 | 110 | 347 | 248 |
Purchases Billed [Member] | WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 24 | $ 39 | $ 71 | $ 79 |
Related Parties (Net Intercompa
Related Parties (Net Intercompany Payables) (Details) - Subsidiary of Common Parent [Member] - Corporate Services [Member] - USD ($) $ in Millions | Sep. 30, 2021 | Dec. 31, 2020 |
IPL [Member] | ||
Related Party Transactions [Line Items] | ||
Net amounts owed | $ 109 | $ 110 |
WPL [Member] | ||
Related Party Transactions [Line Items] | ||
Net amounts owed | $ 80 | $ 73 |
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, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
ATC Billings To WPL [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 29 | $ 27 | $ 91 | $ 80 |
WPL Billings To ATC [Member] | ||||
Related Party Transactions [Line Items] | ||||
Amounts billed between related parties | $ 4 | $ 2 | $ 13 | $ 8 |