Receivables (Tables)

12 Months Ended

Dec. 31, 2020

Accounts Receivable [Line Items]

Accounts Receivable Details

Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):

	Alliant Energy		IPL		WPL
	2020	2019	2020	2019	2020	2019
Customer	$101	$92	$—	$—	$92	$84
Unbilled utility revenues	82	82	—	—	82	82
Deferred proceeds	188	188	188	188	—	—
Other	59	47	23	16	35	31
Allowance for expected credit losses	(18)	(7)	(1)	(1)	(17)	(6)
	$412	$402	$210	$203	$192	$191

Maximum And Average Outstanding Cash Proceeds

IPL’s maximum and average outstanding aggregate cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program were as follows (in millions):

	Maximum			Average
	2020	2019	2018	2020	2019	2018
Outstanding aggregate cash proceeds	$96	$108	$116	$9	$36	$53

Receivables Sold Under the Agreement

As of December 31, the attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):

	2020	2019
Customer accounts receivable	$114	$125
Unbilled utility revenues	92	95
Other receivables	—	1
Receivables sold to third party	206	221
Less: cash proceeds	1	27
Deferred proceeds	205	194
Less: allowance for expected credit losses	17	6
Fair value of deferred proceeds	$188	$188
Outstanding receivables past due	$27	$26

Additional Attributes Of Receivables Sold Under The Agreement

Additional attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):

	2020	2019	2018
Collections	$2,025	$2,193	$2,077
Write-offs, net of recoveries	7	19	21

IPL [Member]

Accounts Receivable [Line Items]

Accounts Receivable Details

Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):

	Alliant Energy		IPL		WPL
	2020	2019	2020	2019	2020	2019
Customer	$101	$92	$—	$—	$92	$84
Unbilled utility revenues	82	82	—	—	82	82
Deferred proceeds	188	188	188	188	—	—
Other	59	47	23	16	35	31
Allowance for expected credit losses	(18)	(7)	(1)	(1)	(17)	(6)
	$412	$402	$210	$203	$192	$191

Maximum And Average Outstanding Cash Proceeds

IPL’s maximum and average outstanding aggregate cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program were as follows (in millions):

	Maximum			Average
	2020	2019	2018	2020	2019	2018
Outstanding aggregate cash proceeds	$96	$108	$116	$9	$36	$53

Receivables Sold Under the Agreement

As of December 31, the attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):

	2020	2019
Customer accounts receivable	$114	$125
Unbilled utility revenues	92	95
Other receivables	—	1
Receivables sold to third party	206	221
Less: cash proceeds	1	27
Deferred proceeds	205	194
Less: allowance for expected credit losses	17	6
Fair value of deferred proceeds	$188	$188
Outstanding receivables past due	$27	$26

Additional Attributes Of Receivables Sold Under The Agreement

Additional attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):

	2020	2019	2018
Collections	$2,025	$2,193	$2,077
Write-offs, net of recoveries	7	19	21

WPL [Member]

Accounts Receivable [Line Items]

Accounts Receivable Details

Details for accounts receivable included on the balance sheets as of December 31 were as follows (in millions):

	Alliant Energy		IPL		WPL
	2020	2019	2020	2019	2020	2019
Customer	$101	$92	$—	$—	$92	$84
Unbilled utility revenues	82	82	—	—	82	82
Deferred proceeds	188	188	188	188	—	—
Other	59	47	23	16	35	31
Allowance for expected credit losses	(18)	(7)	(1)	(1)	(17)	(6)
	$412	$402	$210	$203	$192	$191