Receivables (Tables)

12 Months Ended

Dec. 31, 2019

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
	2019			2018			2019			2018			2019			2018
Customer		$91.6			$91.0			$—			$—			$83.5			$84.8
Unbilled utility revenues	82.1			74.2			—			—			82.1			74.2
Deferred proceeds	187.7			119.4			187.7			119.4			—			—
Other	48.0			76.3			16.3			37.2			31.4			38.5
Allowance for doubtful accounts	(7.3		)	(10.5		)	(1.2		)	(3.1		)	(6.1		)	(7.4		)
		$402.1			$350.4			$202.8			$153.5			$190.9			$190.1

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
	2019	2018	2017	2019	2018	2017
Outstanding aggregate cash proceeds	$108.0	$116.0	$112.0	$35.9	$53.4	$62.2

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):

	2019	2018
Customer accounts receivable	$124.7	$140.1
Unbilled utility revenues	95.5	97.1
Other receivables	0.9	0.1
Receivables sold to third party	221.1	237.3
Less: cash proceeds	27.0	108.0
Deferred proceeds	194.1	129.3
Less: allowance for doubtful accounts	6.4	9.9
Fair value of deferred proceeds	$187.7	$119.4
Outstanding receivables past due	$26.0	$35.5

Additional Attributes Of Receivables Sold Under The Agreement

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

	2019	2018	2017
Collections	$2,192.8	$2,076.7	$1,647.1
Write-offs, net of recoveries	19.2	21.3	17.7

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
	2019			2018			2019			2018			2019			2018
Customer		$91.6			$91.0			$—			$—			$83.5			$84.8
Unbilled utility revenues	82.1			74.2			—			—			82.1			74.2
Deferred proceeds	187.7			119.4			187.7			119.4			—			—
Other	48.0			76.3			16.3			37.2			31.4			38.5
Allowance for doubtful accounts	(7.3		)	(10.5		)	(1.2		)	(3.1		)	(6.1		)	(7.4		)
		$402.1			$350.4			$202.8			$153.5			$190.9			$190.1

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
	2019	2018	2017	2019	2018	2017
Outstanding aggregate cash proceeds	$108.0	$116.0	$112.0	$35.9	$53.4	$62.2

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):

	2019	2018
Customer accounts receivable	$124.7	$140.1
Unbilled utility revenues	95.5	97.1
Other receivables	0.9	0.1
Receivables sold to third party	221.1	237.3
Less: cash proceeds	27.0	108.0
Deferred proceeds	194.1	129.3
Less: allowance for doubtful accounts	6.4	9.9
Fair value of deferred proceeds	$187.7	$119.4
Outstanding receivables past due	$26.0	$35.5

Additional Attributes Of Receivables Sold Under The Agreement

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

	2019	2018	2017
Collections	$2,192.8	$2,076.7	$1,647.1
Write-offs, net of recoveries	19.2	21.3	17.7

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
	2019			2018			2019			2018			2019			2018
Customer		$91.6			$91.0			$—			$—			$83.5			$84.8
Unbilled utility revenues	82.1			74.2			—			—			82.1			74.2
Deferred proceeds	187.7			119.4			187.7			119.4			—			—
Other	48.0			76.3			16.3			37.2			31.4			38.5
Allowance for doubtful accounts	(7.3		)	(10.5		)	(1.2		)	(3.1		)	(6.1		)	(7.4		)
		$402.1			$350.4			$202.8			$153.5			$190.9			$190.1