Debt

6 Months Ended

Jun. 30, 2021

Debt [Line Items]

Debt

DEBT

Short-term Debt - 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):

June 30, 2021	Alliant Energy	IPL	WPL
Amount outstanding	$535	$—	$192
Weighted average interest rates	0.2%	N/A	0.1%
Available credit facility capacity	$465	$250	$108

	Alliant Energy		IPL		WPL
Three Months Ended June 30	2021	2020	2021	2020	2021	2020
Maximum amount outstanding (based on daily outstanding balances)	$571	$271	$19	$8	$232	$182
Average amount outstanding (based on daily outstanding balances)	$452	$121	$1	$—	$177	$9
Weighted average interest rates	0.2%	0.5%	0.2%	0.5%	0.1%	0.5%
Six Months Ended June 30
Maximum amount outstanding (based on daily outstanding balances)	$578	$463	$19	$8	$275	$212
Average amount outstanding (based on daily outstanding balances)	$438	$252	$—	$—	$183	$88
Weighted average interest rates	0.2%	1.5%	0.2%	0.5%	0.1%	1.7%

IPL [Member]

Debt [Line Items]

Debt

DEBT

Short-term Debt - 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):

June 30, 2021	Alliant Energy	IPL	WPL
Amount outstanding	$535	$—	$192
Weighted average interest rates	0.2%	N/A	0.1%
Available credit facility capacity	$465	$250	$108

	Alliant Energy		IPL		WPL
Three Months Ended June 30	2021	2020	2021	2020	2021	2020
Maximum amount outstanding (based on daily outstanding balances)	$571	$271	$19	$8	$232	$182
Average amount outstanding (based on daily outstanding balances)	$452	$121	$1	$—	$177	$9
Weighted average interest rates	0.2%	0.5%	0.2%	0.5%	0.1%	0.5%
Six Months Ended June 30
Maximum amount outstanding (based on daily outstanding balances)	$578	$463	$19	$8	$275	$212
Average amount outstanding (based on daily outstanding balances)	$438	$252	$—	$—	$183	$88
Weighted average interest rates	0.2%	1.5%	0.2%	0.5%	0.1%	1.7%

WPL [Member]

Debt [Line Items]

Debt

DEBT

Short-term Debt - 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):

June 30, 2021	Alliant Energy	IPL	WPL
Amount outstanding	$535	$—	$192
Weighted average interest rates	0.2%	N/A	0.1%
Available credit facility capacity	$465	$250	$108

	Alliant Energy		IPL		WPL
Three Months Ended June 30	2021	2020	2021	2020	2021	2020
Maximum amount outstanding (based on daily outstanding balances)	$571	$271	$19	$8	$232	$182
Average amount outstanding (based on daily outstanding balances)	$452	$121	$1	$—	$177	$9
Weighted average interest rates	0.2%	0.5%	0.2%	0.5%	0.1%	0.5%
Six Months Ended June 30
Maximum amount outstanding (based on daily outstanding balances)	$578	$463	$19	$8	$275	$212
Average amount outstanding (based on daily outstanding balances)	$438	$252	$—	$—	$183	$88
Weighted average interest rates	0.2%	1.5%	0.2%	0.5%	0.1%	1.7%