Defined Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016		Mar. 31, 2015
Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	$ 17		$ 30
Interest cost	43		57
Expected return on plan assets	(56)		(75)
Amortization of:
Prior service cost	1		2
Actuarial (gain) loss	15		24
Net periodic defined benefit costs (credits)	20		38	[1]
Net period defined benefit costs reflected in discontinued operations allocated from PPL's plans to PPL Energy Supply prior to the spinoff			11
Pension Benefits United Kingdom [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	18		20
Interest cost	62		79
Expected return on plan assets	(133)		(131)
Amortization of:
Actuarial (gain) loss	37		39
Net periodic defined benefit costs (credits)	(16)	[2]	7
Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	2		4
Interest cost	6		7
Expected return on plan assets	(5)		(7)
Amortization of:
Net periodic defined benefit costs (credits)	3		4
PPL Electric Utilities Corp [Member] | PPL Services [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	6		8
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	6		7
Interest cost	17		17
Expected return on plan assets	(21)		(22)
Amortization of:
Prior service cost	1		2
Actuarial (gain) loss	5		8
Net periodic defined benefit costs (credits)	8		12
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	1		1
Interest cost	2		2
Expected return on plan assets	(2)		(1)
Amortization of:
Prior service cost	1		1
Net periodic defined benefit costs (credits)	2		3
Louisville Gas And Electric Co [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	2		3
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Interest cost	3		3
Expected return on plan assets	(5)		(5)
Amortization of:
Prior service cost	1		1
Actuarial (gain) loss	2		3
Net periodic defined benefit costs (credits)	1		2
Kentucky Utilities Co [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	$ 3		$ 5

[1] For the three months ended March 31, 2015 , the total net periodic defined benefit cost includes $ 11 million reflected in discontinued operations related to costs allocated from PPL's plans to PPL Energy Supply prior to the spinoff.

[2] See Note 2 for a discussion of changes to the discount rate used for the U.K. Pension Plans.