XML 78 R1.htm IDEA: XBRL DOCUMENT v3.3.0.814
Document And Entity Information
 9 Months Ended
Sep. 30, 2015
shares
Entity Registrant Name ALLIANT ENERGY CORP
Entity Central Index Key 0000352541
Current Fiscal Year End Date --12-31
Entity Filer Category Large Accelerated Filer
Entity Common Stock, Shares Outstanding 113,360,425
Document Fiscal Year Focus 2015
Document Fiscal Period Focus Q3
Document Type 10-Q
Amendment Flag false
Document Period End Date Sep. 30, 2015
IPL [Member]  
Entity Registrant Name INTERSTATE POWER & LIGHT CO
Entity Central Index Key 0000052485
Entity Filer Category Non-accelerated Filer
Entity Common Stock, Shares Outstanding 13,370,788
WPL [Member]  
Entity Registrant Name WISCONSIN POWER & LIGHT CO
Entity Central Index Key 0000107832
Entity Filer Category Non-accelerated Filer
Entity Common Stock, Shares Outstanding 13,236,601