XML 24 R1.htm IDEA: XBRL DOCUMENT v3.8.0.1
Document And Entity Information
9 Months Ended
Sep. 30, 2017
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 231,204,360
Document Fiscal Year Focus 2017
Document Fiscal Period Focus Q3
Document Type 10-Q
Amendment Flag false
Document Period End Date Sep. 30, 2017
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