Receivables (Tables)

12 Months Ended

Dec. 31, 2016

Accounts, Notes, Loans and Financing 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
	2016			2015			2016			2015			2016			2015
Customer		$111.7			$93.8			$—			$4.6			$104.4			$81.5
Unbilled utility revenues	90.2			83.1			—			1.2			90.2			81.9
Deferred proceeds	211.1			172.0			211.1			172.0			—			—
Other	89.0			53.5			30.7			22.8			38.8			25.7
Allowance for doubtful accounts	(8.7		)	(4.8		)	(1.1		)	(0.6		)	(7.1		)	(3.7		)
		$493.3			$397.6			$240.7			$200.0			$226.3			$185.4

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
	2016	2015	2014	2016	2015	2014
Outstanding aggregate cash proceeds	$172.0	$137.0	$150.0	$73.2	$46.7	$46.4

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):

	2016	2015
Customer accounts receivable	$157.6	$109.7
Unbilled utility revenues	90.4	71.3
Other receivables	0.1	0.1
Receivables sold to third party	248.1	181.1
Less: cash proceeds (a)	21.0	5.0
Deferred proceeds	227.1	176.1
Less: allowance for doubtful accounts	16.0	4.1
Fair value of deferred proceeds	$211.1	$172.0
Outstanding receivables past due	$68.0	$18.0

(a) Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements.

Additional Attributes Of Receivables Sold Under The Agreement

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

	2016	2015	2014
Collections reinvested in receivables	$1,818.1	$1,812.9	$1,997.9
Write-offs, net of recoveries	4.8	8.8	11.4

IPL [Member]

Accounts, Notes, Loans and Financing 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
	2016			2015			2016			2015			2016			2015
Customer		$111.7			$93.8			$—			$4.6			$104.4			$81.5
Unbilled utility revenues	90.2			83.1			—			1.2			90.2			81.9
Deferred proceeds	211.1			172.0			211.1			172.0			—			—
Other	89.0			53.5			30.7			22.8			38.8			25.7
Allowance for doubtful accounts	(8.7		)	(4.8		)	(1.1		)	(0.6		)	(7.1		)	(3.7		)
		$493.3			$397.6			$240.7			$200.0			$226.3			$185.4

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
	2016	2015	2014	2016	2015	2014
Outstanding aggregate cash proceeds	$172.0	$137.0	$150.0	$73.2	$46.7	$46.4

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):

	2016	2015
Customer accounts receivable	$157.6	$109.7
Unbilled utility revenues	90.4	71.3
Other receivables	0.1	0.1
Receivables sold to third party	248.1	181.1
Less: cash proceeds (a)	21.0	5.0
Deferred proceeds	227.1	176.1
Less: allowance for doubtful accounts	16.0	4.1
Fair value of deferred proceeds	$211.1	$172.0
Outstanding receivables past due	$68.0	$18.0

(a) Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements.

Additional Attributes Of Receivables Sold Under The Agreement

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

	2016	2015	2014
Collections reinvested in receivables	$1,818.1	$1,812.9	$1,997.9
Write-offs, net of recoveries	4.8	8.8	11.4

WPL [Member]

Accounts, Notes, Loans and Financing 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
	2016			2015			2016			2015			2016			2015
Customer		$111.7			$93.8			$—			$4.6			$104.4			$81.5
Unbilled utility revenues	90.2			83.1			—			1.2			90.2			81.9
Deferred proceeds	211.1			172.0			211.1			172.0			—			—
Other	89.0			53.5			30.7			22.8			38.8			25.7
Allowance for doubtful accounts	(8.7		)	(4.8		)	(1.1		)	(0.6		)	(7.1		)	(3.7		)
		$493.3			$397.6			$240.7			$200.0			$226.3			$185.4