Retirement and Postemployment Benefits (Net Period Defined Benefit Costs (Credits) and Other Changes in Plan Assets and Benefit Obligations) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost		$ 66	$ 96		$ 97
Interest cost		174	194		224
Expected return on plan assets		(228)	(258)		(287)
Amortization of:
Prior service cost (credit)		8	7		20
Actuarial (gain) loss		50	84		28
Net periodic defined benefit costs (credits) prior to settlements and termination benefits		70	123		82
Settlements		3	0		0
Termination benefits		0	0		13
Net periodic defined benefit costs (credits)		73	123		95
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Divestiture		0	(353)	[1]	0
Settlement		(3)	0		0
Net (gain) loss		253	63		574
Prior service costs (credit)		15	18		(8)
Amortization of: [Abstract]
Prior service (cost) credit		(8)	(7)		(20)
Actuarial gain (loss)		(50)	(85)		(28)
Total recognized in OCI and regulatory assets/liabilities	[2]	207	(364)		518
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	[2]	280	(241)		613
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI		236	(269)		319
Regulatory assets/liabilities		(29)	(95)		199
Total recognized in OCI and regulatory assets/liabilities	[2]	207	(364)		518
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)		9
Actuarial (gain) loss		67
Total		76
Amortization from Balance Sheet: [Abstract]
AOCI		18
Regulatory assets/liabilities		58
Total		76
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts		53	71		45
Pension Benefits United Kingdom [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost		69	79		71
Interest cost		235	314		354
Expected return on plan assets		(504)	(523)		(521)
Amortization of:
Prior service cost (credit)		0	0		0
Actuarial (gain) loss		138	158		132
Net periodic defined benefit costs (credits) prior to settlements and termination benefits		(62)	28		36
Settlements		0	0		0
Termination benefits		0	0		0
Net periodic defined benefit costs (credits)		(62)	28		36
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Divestiture		0	0		0
Settlement		0	0		0
Net (gain) loss		7	508		354
Prior service costs (credit)		0	0		0
Amortization of: [Abstract]
Prior service (cost) credit		0	0		0
Actuarial gain (loss)		(138)	(158)		(132)
Total recognized in OCI and regulatory assets/liabilities	[2]	(131)	350		222
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	[2]	(193)	378		258
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
Total recognized in OCI and regulatory assets/liabilities	[2]	(131)	350		222
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)		0
Actuarial (gain) loss		141
Total		141
Amortization from Balance Sheet: [Abstract]
AOCI		141
Regulatory assets/liabilities		0
Total		141
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts		(95)	(21)		(9)
Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost		7	11		12
Interest cost		26	26		31
Expected return on plan assets		(22)	(26)		(26)
Amortization of:
Prior service cost (credit)		0	1		0
Actuarial (gain) loss		1	0		1
Net periodic defined benefit costs (credits) prior to settlements and termination benefits		12	12		18
Settlements		0	0		0
Termination benefits		0	0		0
Net periodic defined benefit costs (credits)		12	12		18
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Divestiture		0	(6)	[1]	0
Settlement		0	0		0
Net (gain) loss		9	(9)		22
Prior service costs (credit)		0	0		7
Amortization of: [Abstract]
Prior service (cost) credit		(1)	(1)		0
Actuarial gain (loss)		(1)	0		(1)
Total recognized in OCI and regulatory assets/liabilities	[2]	7	(16)		28
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	[2]	19	(4)		46
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI		7	12		7
Regulatory assets/liabilities		0	(28)		21
Total recognized in OCI and regulatory assets/liabilities	[2]	7	(16)		28
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts		7	8		10
PPL Electric Utilities Corp [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[3]	10	15		12
PPL Electric Utilities Corp [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[3]	1	0		2
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost		23	26		21
Interest cost		71	68		66
Expected return on plan assets		(91)	(88)		(82)
Amortization of:
Prior service cost (credit)		8	7		5
Actuarial (gain) loss	[4]	21	37		12
Net periodic defined benefit costs (credits)		$ 32	$ 50		22
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 6	$ 9
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss		119	20		162
Prior service costs (credit)		0	19		23
Amortization of: [Abstract]
Prior service (cost) credit		(8)	(7)		(5)
Actuarial gain (loss)		(21)	(37)		(12)
Total recognized in OCI and regulatory assets/liabilities		90	(5)		168
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities		122	45		190
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI		42	4		84
Regulatory assets/liabilities		48	(9)		84
Total recognized in OCI and regulatory assets/liabilities		90	(5)		168
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)		8
Actuarial (gain) loss		30
Total		38
Amortization from Balance Sheet: [Abstract]
AOCI		5
Regulatory assets/liabilities		33
Total		38
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[5]	$ 24	$ 37		17
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ (6)	$ (9)
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost		5	5		4
Interest cost		9	9		9
Expected return on plan assets		(6)	(6)		(4)
Amortization of:
Prior service cost (credit)		3	3		2
Actuarial (gain) loss	[4]	(1)	0		(1)
Net periodic defined benefit costs (credits)		$ 10	$ 11		10
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss		$ 6	$ (15)		26
Prior service costs (credit)		0	0		6
Amortization of: [Abstract]
Prior service (cost) credit		(3)	(3)		(2)
Actuarial gain (loss)		1	0		1
Total recognized in OCI and regulatory assets/liabilities		4	(18)		31
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities		14	(7)		41
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI		2	(2)		9
Regulatory assets/liabilities		2	(16)		22
Total recognized in OCI and regulatory assets/liabilities		4	(18)		31
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)		1
Actuarial (gain) loss		0
Total		1
Amortization from Balance Sheet: [Abstract]
AOCI		0
Regulatory assets/liabilities		1
Total		1
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[5]	$ 6	$ 8		7
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Louisville Gas And Electric Co [Member]
Amortization of:
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 5	$ 3
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		(5)	(3)
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost		1	1		1
Interest cost		15	14		15
Expected return on plan assets		(21)	(20)		(19)
Amortization of:
Prior service cost (credit)		4	3		2
Actuarial (gain) loss	[6]	7	11		6
Net periodic defined benefit costs (credits)		$ 6	$ 9		5
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ (3)	$ (4)
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss		22	8		14
Prior service costs (credit)		0	10		9
Amortization of: [Abstract]
Prior service (cost) credit		(4)	(3)		(2)
Actuarial gain (loss)		(7)	(11)		(6)
Total recognized in OCI and regulatory assets/liabilities		11	4		15
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities		17	13		20
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
Total recognized in OCI and regulatory assets/liabilities		11	4		15
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)		4
Actuarial (gain) loss		9
Total		13
Amortization from Balance Sheet: [Abstract]
Total		13
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[5]	$ 8	$ 12		5
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 3	$ 4
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors		$ 4	$ 5		2
Louisville Gas And Electric Co [Member] | Other Postretirement Benefits United States [Member]
Amortization of:
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ (3)	$ (4)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[5]	$ 3	$ 4		4
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 3	$ 4
Louisville Gas And Electric Co [Member] | Other Postretirement Benefits United States [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors		$ 3	$ 4		4
Kentucky Utilities Co [Member] | Pension Benefits United States [Member]
Amortization of:
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ (2)	$ (1)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[3],[5]	$ 5	$ 9		3
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 2	$ 1
Kentucky Utilities Co [Member] | Other Postretirement Benefits United States [Member]
Amortization of:
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ (2)	$ (1)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	[3],[5]	$ 2	$ 2		$ 2
Amortization period for the deferred recovery of a regulatory asset		15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 2	$ 1

[1] As a result of the spinoff of PPL Energy Supply, amounts in AOCI were allocated to certain former active and inactive employees of PPL Energy Supply and included in the distribution. See Note 8 for additional details.

[2] WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. As a result, WPD does not record regulatory assets/liabilities.

[3] PPL Electric and KU do not directly sponsor any defined benefit plans. PPL Electric and KU were allocated these costs of defined benefit plans sponsored by PPL Services (for PPL Electric) and by LKE (for KU), based on their participation in those plans, which management believes are reasonable.

[4] As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LKE's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $6 million in 2016 and $9 million in 2015.

[5] As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between net periodic defined benefit costs calculated in accordance with LKE's, LG&E's and KU's pension accounting policy and the net periodic defined benefit costs calculated using a 15 year amortization period for gains and losses is recorded as a regulatory asset. Of the costs charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts, $3 million for LG&E and $2 million for KU were recorded as regulatory assets in 2016 and $4 million for LG&E and $1 million for KU were recorded as regulatory assets in 2015.

[6] As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LG&E's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $5 million in 2016 and $3 million in 2015.