Common Equity (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Common Equity [Line Items]

Common Stock Activity

A summary of Alliant Energy’s common stock activity was as follows:

	2015		2014		2013
Shares outstanding, January 1	110,935,680		110,943,669		110,987,400
At-the-market offering program	2,186,617		—		—
Shareowner Direct Plan issuances	303,005		—		—
Equity-based compensation plans (Note 12(b))	56,378		35,547		(23,374	)
Other	(22,464	)	(43,536	)	(20,357	)
Shares outstanding, December 31	113,459,216		110,935,680		110,943,669

Schedule of Restricted Net Assets of Subsidiaries

As of December 31, the amount of net assets of IPL and WPL that were not available to be transferred to their parent company, Alliant Energy, in the form of loans, advances or cash dividends without the consent of IPL’s and WPL’s regulatory authorities was as follows (in billions):

	2015		2014
IPL		$1.4		$1.3
WPL	1.6		1.6

Capital Transactions with Subsidiaries

IPL, WPL and Resources paid common stock dividends and repayments of capital to their parent company, Alliant Energy, as follows (in millions):

	IPL						WPL						Resources
	2015		2014		2013		2015		2014		2013		2015		2014		2013
Common stock dividends		$140.0		$140.0		$128.1		$126.9		$118.7		$116.3		$—		$—		$—
Repayments of capital	—		—		—		—		—		—		—		50.0		95.0
Total distributions from common equity		$140.0		$140.0		$128.1		$126.9		$118.7		$116.3		$—		$50.0		$95.0

Schedule of Capital Contributions

IPL received capital contributions from its parent company, Alliant Energy, as follows (in millions):

2015		2014		2013
	$165.0		$90.0		$120.0

IPL [Member]

Schedule of Common Equity [Line Items]

Schedule of Restricted Net Assets of Subsidiaries

As of December 31, the amount of net assets of IPL and WPL that were not available to be transferred to their parent company, Alliant Energy, in the form of loans, advances or cash dividends without the consent of IPL’s and WPL’s regulatory authorities was as follows (in billions):

	2015		2014
IPL		$1.4		$1.3
WPL	1.6		1.6

Capital Transactions with Subsidiaries

IPL, WPL and Resources paid common stock dividends and repayments of capital to their parent company, Alliant Energy, as follows (in millions):

	IPL						WPL						Resources
	2015		2014		2013		2015		2014		2013		2015		2014		2013
Common stock dividends		$140.0		$140.0		$128.1		$126.9		$118.7		$116.3		$—		$—		$—
Repayments of capital	—		—		—		—		—		—		—		50.0		95.0
Total distributions from common equity		$140.0		$140.0		$128.1		$126.9		$118.7		$116.3		$—		$50.0		$95.0

Schedule of Capital Contributions

IPL received capital contributions from its parent company, Alliant Energy, as follows (in millions):

2015		2014		2013
	$165.0		$90.0		$120.0

WPL [Member]

Schedule of Common Equity [Line Items]

Schedule of Restricted Net Assets of Subsidiaries

As of December 31, the amount of net assets of IPL and WPL that were not available to be transferred to their parent company, Alliant Energy, in the form of loans, advances or cash dividends without the consent of IPL’s and WPL’s regulatory authorities was as follows (in billions):

	2015		2014
IPL		$1.4		$1.3
WPL	1.6		1.6

Capital Transactions with Subsidiaries

IPL, WPL and Resources paid common stock dividends and repayments of capital to their parent company, Alliant Energy, as follows (in millions):

	IPL						WPL						Resources
	2015		2014		2013		2015		2014		2013		2015		2014		2013
Common stock dividends		$140.0		$140.0		$128.1		$126.9		$118.7		$116.3		$—		$—		$—
Repayments of capital	—		—		—		—		—		—		—		50.0		95.0
Total distributions from common equity		$140.0		$140.0		$128.1		$126.9		$118.7		$116.3		$—		$50.0		$95.0