Commitments and Contingencies (Energy Purchases, Other Commitments, Legal Matters and Regulatory Issues) (Details) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended
	Oct. 31, 2015	Mar. 31, 2015 Integer	Jun. 30, 2015 Integer	Sep. 30, 2015 USD ($) Integer mi
Regulatory Issues - Electric - Reliability Standards (Numeric) [Abstract]
Maximum per day penalties for reliability violations | $				$ 1
LGE [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of residents that filed class action suit				6
Number of miles within plant that would include a class of residents | mi				4
Number of remaining unresolved Clean Air Act violation claims after July 2014 court ruling				1
Generating units retired at the Cane Run plant		1	2
KU [Member] | Subsequent Event [Member]
Legal Matters - E.W. Brown Environmental Claims [Abstract]
Period to file lawsuits after applicable notice date (in days)	60 days
LG And E And KU Energy LLC [Member] | LGE [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of residents that filed class action suit				6
Number of miles within plant that would include a class of residents | mi				4
Number of remaining unresolved Clean Air Act violation claims after July 2014 court ruling				1
Generating units retired at the Cane Run plant		1	2
LG And E And KU Energy LLC [Member] | KU [Member] | Subsequent Event [Member]
Legal Matters - E.W. Brown Environmental Claims [Abstract]
Period to file lawsuits after applicable notice date (in days)	60 days
Louisville Gas And Electric Co [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of residents that filed class action suit				6
Number of miles within plant that would include a class of residents | mi				4
Number of remaining unresolved Clean Air Act violation claims after July 2014 court ruling				1
Generating units retired at the Cane Run plant		1	2
Kentucky Utilities Co [Member] | Subsequent Event [Member]
Legal Matters - E.W. Brown Environmental Claims [Abstract]
Period to file lawsuits after applicable notice date (in days)	60 days