Debt (Tables)

9 Months Ended

Sep. 30, 2020

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, 2020	Alliant Energy	IPL	WPL
Amount outstanding	$422	$—	$139
Weighted average interest rates	0.2%	N/A	0.1%
Available credit facility capacity	$578	$250	$161

	Alliant Energy				IPL				WPL
Three Months Ended September 30	2020		2019		2020		2019		2020		2019
Maximum amount outstanding (based on daily outstanding balances)		$422		$472		$—		$—		$139		$90
Average amount outstanding (based on daily outstanding balances)		$252		$400		$—		$—		$83		$27
Weighted average interest rates	0.2%		2.5%		N/A		N/A		0.2%		2.3%
Nine Months Ended September 30
Maximum amount outstanding (based on daily outstanding balances)		$463		$601		$8		$50		$212		$195
Average amount outstanding (based on daily outstanding balances)		$252		$476		$—		$—		$86		$102
Weighted average interest rates	1.1%		2.6%		0.5%		2.8%		1.2%		2.5%

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, 2020	Alliant Energy	IPL	WPL
Amount outstanding	$422	$—	$139
Weighted average interest rates	0.2%	N/A	0.1%
Available credit facility capacity	$578	$250	$161

	Alliant Energy				IPL				WPL
Three Months Ended September 30	2020		2019		2020		2019		2020		2019
Maximum amount outstanding (based on daily outstanding balances)		$422		$472		$—		$—		$139		$90
Average amount outstanding (based on daily outstanding balances)		$252		$400		$—		$—		$83		$27
Weighted average interest rates	0.2%		2.5%		N/A		N/A		0.2%		2.3%
Nine Months Ended September 30
Maximum amount outstanding (based on daily outstanding balances)		$463		$601		$8		$50		$212		$195
Average amount outstanding (based on daily outstanding balances)		$252		$476		$—		$—		$86		$102
Weighted average interest rates	1.1%		2.6%		0.5%		2.8%		1.2%		2.5%

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, 2020	Alliant Energy	IPL	WPL
Amount outstanding	$422	$—	$139
Weighted average interest rates	0.2%	N/A	0.1%
Available credit facility capacity	$578	$250	$161

	Alliant Energy				IPL				WPL
Three Months Ended September 30	2020		2019		2020		2019		2020		2019
Maximum amount outstanding (based on daily outstanding balances)		$422		$472		$—		$—		$139		$90
Average amount outstanding (based on daily outstanding balances)		$252		$400		$—		$—		$83		$27
Weighted average interest rates	0.2%		2.5%		N/A		N/A		0.2%		2.3%
Nine Months Ended September 30
Maximum amount outstanding (based on daily outstanding balances)		$463		$601		$8		$50		$212		$195
Average amount outstanding (based on daily outstanding balances)		$252		$476		$—		$—		$86		$102
Weighted average interest rates	1.1%		2.6%		0.5%		2.8%		1.2%		2.5%