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Debt (Tables)

6 Months Ended

Jun. 30, 2017

Debt Disclosure [Line Items]

Other Short-Term Borrowings

Information regarding commercial paper classified as short-term debt was as follows (dollars in millions):

June 30, 2017	Alliant Energy		IPL		WPL
Commercial paper outstanding	$368.6		$—		$212.5
Commercial paper weighted average interest rates	1.3%		N/A		1.1%
Available credit facility capacity (a)	$591.4		$260.0		$187.5

	Alliant Energy				IPL				WPL
Three Months Ended June 30	2017		2016		2017		2016		2017		2016
Maximum amount outstanding (based on daily outstanding balances)	$397.6		$229.9		$14.6		$1.7		$212.5		$62.9
Average amount outstanding (based on daily outstanding balances)	$307.8		$213.0		$1.0		$—		$134.9		$37.4
Weighted average interest rates	1.1%		0.6%		1.2%		0.6%		1.0%		0.4%
Six Months Ended June 30
Maximum amount outstanding (based on daily outstanding balances)	$397.6		$242.6		$14.6		$1.7		$212.5		$62.9
Average amount outstanding (based on daily outstanding balances)	$292.3		$206.0		$0.6		$—		$107.2		$31.6
Weighted average interest rates	1.0%		0.6%		1.2%		0.6%		0.9%		0.4%

(a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at June 30, 2017.

IPL [Member]

Debt Disclosure [Line Items]

Other Short-Term Borrowings

Information regarding commercial paper classified as short-term debt was as follows (dollars in millions):

June 30, 2017	Alliant Energy		IPL		WPL
Commercial paper outstanding	$368.6		$—		$212.5
Commercial paper weighted average interest rates	1.3%		N/A		1.1%
Available credit facility capacity (a)	$591.4		$260.0		$187.5

	Alliant Energy				IPL				WPL
Three Months Ended June 30	2017		2016		2017		2016		2017		2016
Maximum amount outstanding (based on daily outstanding balances)	$397.6		$229.9		$14.6		$1.7		$212.5		$62.9
Average amount outstanding (based on daily outstanding balances)	$307.8		$213.0		$1.0		$—		$134.9		$37.4
Weighted average interest rates	1.1%		0.6%		1.2%		0.6%		1.0%		0.4%
Six Months Ended June 30
Maximum amount outstanding (based on daily outstanding balances)	$397.6		$242.6		$14.6		$1.7		$212.5		$62.9
Average amount outstanding (based on daily outstanding balances)	$292.3		$206.0		$0.6		$—		$107.2		$31.6
Weighted average interest rates	1.0%		0.6%		1.2%		0.6%		0.9%		0.4%

(a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at June 30, 2017.

WPL [Member]

Debt Disclosure [Line Items]

Other Short-Term Borrowings

Information regarding commercial paper classified as short-term debt was as follows (dollars in millions):

June 30, 2017	Alliant Energy		IPL		WPL
Commercial paper outstanding	$368.6		$—		$212.5
Commercial paper weighted average interest rates	1.3%		N/A		1.1%
Available credit facility capacity (a)	$591.4		$260.0		$187.5

	Alliant Energy				IPL				WPL
Three Months Ended June 30	2017		2016		2017		2016		2017		2016
Maximum amount outstanding (based on daily outstanding balances)	$397.6		$229.9		$14.6		$1.7		$212.5		$62.9
Average amount outstanding (based on daily outstanding balances)	$307.8		$213.0		$1.0		$—		$134.9		$37.4
Weighted average interest rates	1.1%		0.6%		1.2%		0.6%		1.0%		0.4%
Six Months Ended June 30
Maximum amount outstanding (based on daily outstanding balances)	$397.6		$242.6		$14.6		$1.7		$212.5		$62.9
Average amount outstanding (based on daily outstanding balances)	$292.3		$206.0		$0.6		$—		$107.2		$31.6
Weighted average interest rates	1.0%		0.6%		1.2%		0.6%		0.9%		0.4%

(a) Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at June 30, 2017.

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[Line Items] for Debt Disclosure [Table] [Table]

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Tabular disclosure of short-term debt arrangements (having initial terms of repayment within one year or the normal operating cycle, if longer) including: (1) description of the short-term debt arrangement; (2) identification of the lender or type of lender; (3) repayment terms; (4) weighted average interest rate; (5) carrying amount of funds borrowed under the specified short-term debt arrangement as of the balance sheet date; (6) description of the refinancing of a short-term obligation when that obligation is excluded from current liabilities in the balance sheet; and (7) amount of a short-term obligation that has been excluded from current liabilities in the balance sheet because of a refinancing of the obligation.

+ 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 210.5-02.19)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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