Leases (Tables)

6 Months Ended

Jun. 30, 2019

Leases [Line Items]

Schedule of Lease Details

Operating lease details are as follows (dollars in millions):

	June 30, 2019
	Alliant Energy			IPL			WPL
Property, plant and equipment, net		$17			$10			$7
Other current liabilities		$2			$1			$1
Other liabilities	15			9			6
Total operating lease liabilities		$17			$10			$7
Weighted average remaining lease term	11 years			13 years			10 years
Weighted average discount rate	4		%	4		%	4		%
	Three Months Ended									Six Months Ended
	June 30, 2019									June 30, 2019
	Alliant Energy			IPL			WPL			Alliant Energy		IPL		WPL
Operating lease cost		$—			$—			$—			$1		$—		$—

Schedule of Operating Lease Liability Maturities

As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):

	Remainder of 2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum lease payments
Operating Leases:
Alliant Energy		$2		$2		$2		$2		$2		$13		$23		$6		$17
IPL	1		1		1		1		1		9		14		4		10
WPL	1		1		1		1		1		4		9		2		7
WPL’s Finance Lease:
Sheboygan Falls Energy Facility	7		15		15		15		15		20		87		23		64

Schedule of Future Minimum Payments for Operating Leases

As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):

	2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum capital lease payments
Operating Leases:
Alliant Energy		$5		$5		$3		$3		$2		$12		$30
IPL	3		2		2		2		2		12		23
WPL	2		3		1		—		—		—		6
WPL’s Capital Lease:
Sheboygan Falls Energy Facility		$15		$15		$15		$15		$15		$19		$94		$26		$68

IPL [Member]

Leases [Line Items]

Schedule of Lease Details

Operating lease details are as follows (dollars in millions):

	June 30, 2019
	Alliant Energy			IPL			WPL
Property, plant and equipment, net		$17			$10			$7
Other current liabilities		$2			$1			$1
Other liabilities	15			9			6
Total operating lease liabilities		$17			$10			$7
Weighted average remaining lease term	11 years			13 years			10 years
Weighted average discount rate	4		%	4		%	4		%
	Three Months Ended									Six Months Ended
	June 30, 2019									June 30, 2019
	Alliant Energy			IPL			WPL			Alliant Energy		IPL		WPL
Operating lease cost		$—			$—			$—			$1		$—		$—

Schedule of Operating Lease Liability Maturities

As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):

	Remainder of 2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum lease payments
Operating Leases:
Alliant Energy		$2		$2		$2		$2		$2		$13		$23		$6		$17
IPL	1		1		1		1		1		9		14		4		10
WPL	1		1		1		1		1		4		9		2		7
WPL’s Finance Lease:
Sheboygan Falls Energy Facility	7		15		15		15		15		20		87		23		64

Schedule of Future Minimum Payments for Operating Leases

As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):

	2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum capital lease payments
Operating Leases:
Alliant Energy		$5		$5		$3		$3		$2		$12		$30
IPL	3		2		2		2		2		12		23
WPL	2		3		1		—		—		—		6
WPL’s Capital Lease:
Sheboygan Falls Energy Facility		$15		$15		$15		$15		$15		$19		$94		$26		$68

WPL [Member]

Leases [Line Items]

Schedule of Lease Details

WPL’s finance lease details are as follows (dollars in millions):

	June 30, 2019
Property, plant and equipment, net		$35
Other current liabilities		$8
Finance lease obligations - Sheboygan Falls Energy Facility	56
Total finance lease liabilities		$64
Remaining lease term	6 years
Discount rate	11		%
	Three Months Ended			Six Months Ended
	June 30, 2019			June 30, 2019
Depreciation expense		$2			$3
Interest expense	2			4
Total finance lease expense		$4			$7

Operating lease details are as follows (dollars in millions):

	June 30, 2019
	Alliant Energy			IPL			WPL
Property, plant and equipment, net		$17			$10			$7
Other current liabilities		$2			$1			$1
Other liabilities	15			9			6
Total operating lease liabilities		$17			$10			$7
Weighted average remaining lease term	11 years			13 years			10 years
Weighted average discount rate	4		%	4		%	4		%
	Three Months Ended									Six Months Ended
	June 30, 2019									June 30, 2019
	Alliant Energy			IPL			WPL			Alliant Energy		IPL		WPL
Operating lease cost		$—			$—			$—			$1		$—		$—

Schedule of Operating Lease Liability Maturities

As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):

	Remainder of 2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum lease payments
Operating Leases:
Alliant Energy		$2		$2		$2		$2		$2		$13		$23		$6		$17
IPL	1		1		1		1		1		9		14		4		10
WPL	1		1		1		1		1		4		9		2		7
WPL’s Finance Lease:
Sheboygan Falls Energy Facility	7		15		15		15		15		20		87		23		64

Schedule of Finance Lease Liability Maturities

As of June 30, 2019, expected maturities of lease liabilities were as follows (in millions):

	Remainder of 2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum lease payments
Operating Leases:
Alliant Energy		$2		$2		$2		$2		$2		$13		$23		$6		$17
IPL	1		1		1		1		1		9		14		4		10
WPL	1		1		1		1		1		4		9		2		7
WPL’s Finance Lease:
Sheboygan Falls Energy Facility	7		15		15		15		15		20		87		23		64

Schedule of Future Minimum Payments for Operating Leases

As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):

	2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum capital lease payments
Operating Leases:
Alliant Energy		$5		$5		$3		$3		$2		$12		$30
IPL	3		2		2		2		2		12		23
WPL	2		3		1		—		—		—		6
WPL’s Capital Lease:
Sheboygan Falls Energy Facility		$15		$15		$15		$15		$15		$19		$94		$26		$68

Schedule of Future Minimum Payments for Capital Leases

As of December 31, 2018, future minimum operating (excluding contingent rentals) and capital lease payments were as follows (in millions):

	2019		2020		2021		2022		2023		Thereafter		Total		Less: amount representing interest		Present value of minimum capital lease payments
Operating Leases:
Alliant Energy		$5		$5		$3		$3		$2		$12		$30
IPL	3		2		2		2		2		12		23
WPL	2		3		1		—		—		—		6
WPL’s Capital Lease:
Sheboygan Falls Energy Facility		$15		$15		$15		$15		$15		$19		$94		$26		$68