Receivables (Tables)

12 Months Ended

Dec. 31, 2018

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
	2018			2017			2018			2017			2018			2017
Customer		$91.0			$103.3			$—			$—			$84.8			$97.7
Unbilled utility revenues	74.2			85.1			—			—			74.2			85.1
Deferred proceeds	119.4			222.1			119.4			222.1			—			—
Other	76.3			84.3			37.2			44.1			38.5			40.1
Allowance for doubtful accounts	(10.5		)	(12.0		)	(3.1		)	(1.3		)	(7.4		)	(10.7		)
		$350.4			$482.8			$153.5			$264.9			$190.1			$212.2

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
	2018	2017	2016	2018	2017	2016
Outstanding aggregate cash proceeds	$116.0	$112.0	$172.0	$53.4	$62.2	$73.2

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):

	2018	2017
Customer accounts receivable	$140.1	$133.8
Unbilled utility revenues	97.1	112.7
Other receivables	0.1	0.3
Receivables sold to third party	237.3	246.8
Less: cash proceeds	108.0	12.0
Deferred proceeds	129.3	234.8
Less: allowance for doubtful accounts	9.9	12.7
Fair value of deferred proceeds	$119.4	$222.1
Outstanding receivables past due	$35.5	$44.7

Additional Attributes Of Receivables Sold Under The Agreement

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

	2018	2017	2016
Collections	$2,076.7	$1,647.1	$1,818.1
Write-offs, net of recoveries	21.3	17.7	4.8

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
	2018			2017			2018			2017			2018			2017
Customer		$91.0			$103.3			$—			$—			$84.8			$97.7
Unbilled utility revenues	74.2			85.1			—			—			74.2			85.1
Deferred proceeds	119.4			222.1			119.4			222.1			—			—
Other	76.3			84.3			37.2			44.1			38.5			40.1
Allowance for doubtful accounts	(10.5		)	(12.0		)	(3.1		)	(1.3		)	(7.4		)	(10.7		)
		$350.4			$482.8			$153.5			$264.9			$190.1			$212.2

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
	2018	2017	2016	2018	2017	2016
Outstanding aggregate cash proceeds	$116.0	$112.0	$172.0	$53.4	$62.2	$73.2

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):

	2018	2017
Customer accounts receivable	$140.1	$133.8
Unbilled utility revenues	97.1	112.7
Other receivables	0.1	0.3
Receivables sold to third party	237.3	246.8
Less: cash proceeds	108.0	12.0
Deferred proceeds	129.3	234.8
Less: allowance for doubtful accounts	9.9	12.7
Fair value of deferred proceeds	$119.4	$222.1
Outstanding receivables past due	$35.5	$44.7

Additional Attributes Of Receivables Sold Under The Agreement

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

	2018	2017	2016
Collections	$2,076.7	$1,647.1	$1,818.1
Write-offs, net of recoveries	21.3	17.7	4.8

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
	2018			2017			2018			2017			2018			2017
Customer		$91.0			$103.3			$—			$—			$84.8			$97.7
Unbilled utility revenues	74.2			85.1			—			—			74.2			85.1
Deferred proceeds	119.4			222.1			119.4			222.1			—			—
Other	76.3			84.3			37.2			44.1			38.5			40.1
Allowance for doubtful accounts	(10.5		)	(12.0		)	(3.1		)	(1.3		)	(7.4		)	(10.7		)
		$350.4			$482.8			$153.5			$264.9			$190.1			$212.2