|
Common Equity (Capital Transactions With Subsidiaries) (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Common stock dividends | $ 199.3 | $ 188.1 | $ 174.6 |
|
IPL [Member]
|
|||
| Common stock dividends | 122.9 | 73.4 | 0 |
| Repayments of capital | 0 | (100.7) | (118.2) |
| Total distributions from common equity | 122.9 | 174.1 | 118.2 |
|
WPL [Member]
|
|||
| Common stock dividends | 112.0 | 112.1 | 109.5 |
| Repayments of capital | 0 | 0 | 0 |
| Total distributions from common equity | 112.0 | 112.1 | 109.5 |
|
Resources [Member]
|
|||
| Common stock dividends | 0 | 0 | 0 |
| Repayments of capital | 0 | 0 | (65.0) |
| Total distributions from common equity | $ 0 | $ 0 | $ 65.0 |