Defined Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	$ 15	$ 16	$ 32	$ 33
Interest cost	42	44	84	87
Expected return on plan assets	(58)	(58)	(115)	(114)
Amortization of: [Abstract]
Prior service cost	3	3	5	4
Actuarial loss	14	10	34	25
Net periodic defined benefit costs (credits) before special termination benefits	16	15	40	35
Special termination benefits	(1)	0	1	0
Net periodic defined benefit costs (credits)	15	15	41	35
Pension Benefits United Kingdom [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	18	18	37	36
Interest cost	44	62	87	124
Expected return on plan assets	(127)	(132)	(252)	(265)
Amortization of: [Abstract]
Prior service cost	0	0	0	0
Actuarial loss	36	36	71	73
Net periodic defined benefit costs (credits) before special termination benefits	(29)	(16)	(57)	(32)
Special termination benefits	0	0	0	0
Net periodic defined benefit costs (credits)	(29)	(16)	(57)	(32)
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Employer contributions			485
Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	2	2	4	4
Interest cost	6	7	12	13
Expected return on plan assets	(5)	(6)	(11)	(11)
Amortization of: [Abstract]
Prior service cost	(1)	0	(1)	0
Net periodic defined benefit costs (credits)	2	3	4	6
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	5	5	13	11
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	5	6	12	12
Interest cost	18	18	34	35
Expected return on plan assets	(24)	(24)	(46)	(45)
Amortization of: [Abstract]
Prior service cost	2	3	4	4
Actuarial loss	4	5	15	10
Net periodic defined benefit costs (credits)	5	8	19	16
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	2	2
Interest cost	2	3	4	5
Expected return on plan assets	(2)	(1)	(3)	(3)
Amortization of: [Abstract]
Prior service cost	0	0	0	1
Net periodic defined benefit costs (credits)	1	3	3	5
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	5	5
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) (Details) [Abstract]
Service cost	1	1	1	1
Interest cost	3	4	6	7
Expected return on plan assets	(6)	(5)	(11)	(10)
Amortization of: [Abstract]
Prior service cost	1	1	2	2
Actuarial loss	1	1	4	3
Net periodic defined benefit costs (credits)	0	2	2	3
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	$ 1	$ 3	$ 5	$ 6