Commitments and Contingencies (Energy Purchases, Other Commitments, Legal Matters and Regulatory Issues) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 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
Additional generating units retired at the Cane Run plant	2
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
Additional generating units retired at the Cane Run plant	2
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
Additional generating units retired at the Cane Run plant	2