Receivables (Tables)

3 Months Ended

Mar. 31, 2012

Receivables [Abstract]

Maximum And Average Outstanding Cash Proceeds

	2012		2011
Maximum outstanding aggregate cash proceeds (based on daily outstanding balances)	$	160.0	$	130.0
Average outstanding aggregate cash proceeds (based on daily outstanding balances)		143.0		91.4
Costs incurred		0.4		0.4

Receivables Sold Under The Agreement

	March 31, 2012		Dec. 31, 2011
Customer accounts receivable	$	116.1	$	122.4
Unbilled utility revenues		48.7		65.4
Other receivables		14.8		7.5
Receivables sold		179.6		195.3
Less: cash proceeds (a)		145.0		140.0
Deferred proceeds		34.6		55.3
Less: allowance for doubtful accounts		1.7		1.6
Fair value of deferred proceeds	$	32.9	$	53.7
Outstanding receivables past due	$	18.0	$	15.9

(a) Changes in cash proceeds during the first quarter of 2012 are recorded in "Sales of accounts receivable" in operating activities in Alliant Energy's and IPL's Condensed Consolidated Statements of Cash Flows.

Additional Attributes Of Receivables Sold Under The Agreement

	2012		2011
Collections reinvested in receivables	$	442.3	$	475.3
Credit losses, net of recoveries		2.1		2.1