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v3.19.1

Common Equity (Changes in Shareowners' Equity) (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2019 | Mar. 31, 2018
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | $ 4,585.7 |
Beginning balance | 4,785.7 | $ 4,382.2
Net income attributable to common shareowners | 125.1 | 120.9
Common stock dividends | (83.7) | (77.5)
Equity forward settlements and Shareowner Direct Plan issuances | 54.6 | 6.3
Equity-based compensation plans and other | 0.0 | (0.4)
Other comprehensive income, net of tax | 0.7 |
Ending balance | 4,682.4 |
Ending balance | $ 4,882.4 | $ 4,431.5
Common stock dividends (in dollars per share) | $ 0.355 | $ 0.335
Common Stock [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | $ 2.4 | $ 2.3
Ending balance | 2.4 | 2.3
Additional Paid-in Capital [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 2,045.5 | 1,845.5
Equity forward settlements and Shareowner Direct Plan issuances | 54.6 | 6.3
Equity-based compensation plans and other | (0.1) | (0.4)
Ending balance | 2,100.0 | 1,851.4
Retained Earnings [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 2,545.9 | 2,346.0
Net income attributable to common shareowners | 125.1 | 120.9
Common stock dividends | (83.7) | (77.5)
Ending balance | 2,587.3 | 2,389.4
Accumulated Other Comprehensive Income (Loss) [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 1.7 | (0.5)
Other comprehensive income, net of tax | 0.7 |
Ending balance | 2.4 | (0.5)
Shares in Deferred Compensation Trust [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | (9.8) | (11.1)
Equity-based compensation plans and other | 0.1 |
Ending balance | (9.7) | (11.1)
Cumulative Preferred Stock [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 200.0 | 200.0
Ending balance | 200.0 | 200.0
IPL [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 3,030.7 |
Beginning balance | 3,230.7 | 2,709.7
Net income attributable to common shareowners | 53.3 | 46.7
Common stock dividends | (42.0) | (41.9)
Capital contributions from parent | 100.0 | 0.0
Other comprehensive income, net of tax | 0.0 | 0.0
Ending balance | 3,142.0 |
Ending balance | 3,342.0 | 2,714.5
IPL [Member] | Common Stock [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 33.4 | 33.4
Ending balance | 33.4 | 33.4
IPL [Member] | Additional Paid-in Capital [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 2,222.8 | 1,797.8
Capital contributions from parent | 100.0 |
Ending balance | 2,322.8 | 1,797.8
IPL [Member] | Retained Earnings [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 774.5 | 678.5
Net income attributable to common shareowners | 53.3 | 46.7
Common stock dividends | (42.0) | (41.9)
Ending balance | 785.8 | 683.3
IPL [Member] | Cumulative Preferred Stock [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 200.0 | 200.0
Ending balance | 200.0 | 200.0
WPL [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 2,149.5 |
Beginning balance | 2,149.5 | 1,881.5
Net income attributable to common shareowners | 65.7 | 54.0
Common stock dividends | (36.0) | (35.0)
Other comprehensive income, net of tax | 0.0 | 0.0
Ending balance | 2,179.2 |
Ending balance | 2,179.2 | 1,900.5
WPL [Member] | Common Stock [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 66.2 | 66.2
Ending balance | 66.2 | 66.2
WPL [Member] | Additional Paid-in Capital [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 1,309.0 | 1,109.0
Ending balance | 1,309.0 | 1,109.0
WPL [Member] | Retained Earnings [Member] |  |
Changes in Shareowners' Equity Roll Forward [Line Items] |  |
Beginning balance | 774.3 | 706.3
Net income attributable to common shareowners | 65.7 | 54.0
Common stock dividends | (36.0) | (35.0)
Ending balance | $ 804.0 | $ 725.3

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- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(30)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 4.E) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(31)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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