Retirement and Postemployment Benefits (Net Period Defined Benefit Costs (Credits) and Other Changes in Plan Assets and Benefit Obligations) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	$ 102		$ 126		$ 103
Interest cost	233		213		220
Expected return on plan assets	(298)		(293)		(259)
Amortization of:
Transition (asset) obligation	0		0		0
Prior service cost (credits)	20		22		24
Actuarial (gain) loss	30		80		42
Net periodic defined benefit costs (credits) prior to settlement charges, curtailment charges (credits) and termination benefits	87		148		130
Settlement charges	0		0		11
Curtailment charges (credits)	0		0		0
Termination benefits	13		0		0
Net periodic defined benefit costs (credits)	100		148		141
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Curtailments	0		0		0
Settlements	0		0		(11)
Net (gain) loss	600		(319)		372
Prior service costs (credit)	(8)		0		0
Amortization of: [Abstract]
Transition asset (obligation)	0		0		0
Prior service (cost) credit	(20)		(22)		(24)
Actuarial gain (loss)	(30)		(80)		(42)
Total recognized in OCI and regulatory assets/liabilities	542		(421)		295
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	642		(273)		436
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	343		(228)		181
Regulatory assets/liabilities	199		(193)		114
Total recognized in OCI and regulatory assets/liabilities	542		(421)		295
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)	7
Actuarial (gain) loss	100
Total	107
Amortization from Balance Sheet: [Abstract]
AOCI	49
Regulatory assets/liabilities	58
Total	107
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	84		117		119
Pension Benefits United Kingdom [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	71		69		54
Interest cost	354		320		340
Expected return on plan assets	(521)		(465)		(458)
Amortization of:
Transition (asset) obligation	0		0		0
Prior service cost (credits)	0		1		4
Actuarial (gain) loss	132		150		79
Net periodic defined benefit costs (credits) prior to settlement charges, curtailment charges (credits) and termination benefits	36		75		19
Settlement charges	0		0		0
Curtailment charges (credits)	0		0		0
Termination benefits	0	[1]	3	[1]	2	[1]
Net periodic defined benefit costs (credits)	36		78		21
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Curtailments	0		0		0
Settlements	0		0		0
Net (gain) loss	354		76		1,073
Prior service costs (credit)	0		0		0
Amortization of: [Abstract]
Transition asset (obligation)	0		0		0
Prior service (cost) credit	0		(1)		(4)
Actuarial gain (loss)	(132)		(150)		(79)
Total recognized in OCI and regulatory assets/liabilities	222	[2]	(75)	[2]	990	[2]
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	258	[2]	3	[2]	1,011	[2]
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	222	[2]	(75)	[2]	990	[2]
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	162
Total	162
Amortization from Balance Sheet: [Abstract]
AOCI	162
Regulatory assets/liabilities	0
Total	162
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	(9)		33		25
Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	12		14		12
Interest cost	32		29		31
Expected return on plan assets	(26)		(25)		(23)
Amortization of:
Transition (asset) obligation	0		0		2
Prior service cost (credits)	0		0		1
Actuarial (gain) loss	1		6		4
Net periodic defined benefit costs (credits) prior to settlement charges, curtailment charges (credits) and termination benefits	19		24		27
Settlement charges	0		0		0
Curtailment charges (credits)	(1)		0		0
Termination benefits	0		0		0
Net periodic defined benefit costs (credits)	18		24		27
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Curtailments	1		0		0
Settlements	0		0		0
Net (gain) loss	21		(68)		13
Prior service costs (credit)	7		(3)		(1)
Amortization of: [Abstract]
Transition asset (obligation)	0		0		(2)
Prior service (cost) credit	0		0		(1)
Actuarial gain (loss)	(1)		(6)		(4)
Total recognized in OCI and regulatory assets/liabilities	28		(77)		5
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	46		(53)		32
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	7		(41)		12
Regulatory assets/liabilities	21		(36)		(7)
Total recognized in OCI and regulatory assets/liabilities	28		(77)		5
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	13		19		22
PPL Energy Supply LLC [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	5		7		6
Interest cost	9		8		7
Expected return on plan assets	(11)		(10)		(9)
Amortization of:
Actuarial (gain) loss	2		3		2
Curtailment charges (credits)	0		0		0
Net periodic defined benefit costs (credits)	5		8		6
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Curtailments	0		0		0
Net (gain) loss	26		(15)		16
Prior service costs (credit)	0		0		0
Amortization of: [Abstract]
Actuarial gain (loss)	(2)		(3)		(2)
Total recognized in OCI and regulatory assets/liabilities	24		(18)		14
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	29		(10)		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	24		(18)		14
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Actuarial (gain) loss	4
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	39		45		37
PPL Energy Supply LLC [Member] | Pension Benefits United States [Member] | PPL Services [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	34		38		31
PPL Energy Supply LLC [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	0		1		1
Interest cost	1		0		1
Expected return on plan assets	0		0		0
Amortization of:
Actuarial (gain) loss	0		0		0
Curtailment charges (credits)	(1)		0		0
Net periodic defined benefit costs (credits)	0		1		2
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Curtailments	1		0		0
Net (gain) loss	(1)		(1)		0
Prior service costs (credit)	0		(3)		(1)
Amortization of: [Abstract]
Actuarial gain (loss)	0		0		0
Total recognized in OCI and regulatory assets/liabilities	0		(4)		(1)
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	0		(3)		1
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	0		(4)		(1)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	3		6		6
PPL Energy Supply LLC [Member] | Other Postretirement Benefits United States [Member] | PPL Services [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	3		5		5
PPL Electric Utilities Corp [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	12	[3]	18	[3]	19	[3]
PPL Electric Utilities Corp [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	2	[3]	3	[3]	3	[3]
LG And E And KU Energy LLC [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	21		26		22
Interest cost	66		62		64
Expected return on plan assets	(82)		(82)		(70)
Amortization of:
Transition (asset) obligation	0		0		0
Prior service cost (credits)	5		5		5
Actuarial (gain) loss	12		33		22
Net periodic defined benefit costs (credits)	22		44		43
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss	162		(116)		96
Prior service costs (credit)	23		0		0
Amortization of: [Abstract]
Transition asset (obligation)	0		0		0
Prior service (cost) credit	(5)		(5)		(5)
Actuarial gain (loss)	(12)		(33)		(22)
Total recognized in OCI and regulatory assets/liabilities	168		(154)		69
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	190		(110)		112
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	84		(46)		34
Regulatory assets/liabilities	84		(108)		35
Total recognized in OCI and regulatory assets/liabilities	168		(154)		69
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)	7
Actuarial (gain) loss	34
Total	41
Amortization from Balance Sheet: [Abstract]
AOCI	3
Regulatory assets/liabilities	38
Total	41
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	17		32		31
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	4		5		4
Interest cost	9		8		9
Expected return on plan assets	(4)		(5)		(4)
Amortization of:
Transition (asset) obligation	0		0		2
Prior service cost (credits)	2		3		3
Actuarial (gain) loss	(1)		0		(1)
Net periodic defined benefit costs (credits)	10		11		13
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss	26		(14)		(11)
Prior service costs (credit)	6		0		0
Amortization of: [Abstract]
Transition asset (obligation)	0		0		(2)
Prior service (cost) credit	(2)		(3)		(3)
Actuarial gain (loss)	1		0		1
Total recognized in OCI and regulatory assets/liabilities	31		(17)		(15)
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	41		(6)		(2)
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	9		(1)		(1)
Regulatory assets/liabilities	22		(16)		(14)
Total recognized in OCI and regulatory assets/liabilities	31		(17)		(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)	3
Actuarial (gain) loss	0
Total	3
Amortization from Balance Sheet: [Abstract]
AOCI	1
Regulatory assets/liabilities	2
Total	3
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	7		8		9
Louisville Gas And Electric Co [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	1		2		2
Interest cost	15		14		14
Expected return on plan assets	(19)		(20)		(19)
Amortization of:
Prior service cost (credits)	2		2		3
Actuarial (gain) loss	6		14		11
Net periodic defined benefit costs (credits)	5		12		11
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss	14		(20)		18
Prior service costs (credit)	9		0		0
Amortization of: [Abstract]
Prior service (cost) credit	(2)		(2)		(2)
Actuarial gain (loss)	(6)		(14)		(11)
Total recognized in OCI and regulatory assets/liabilities	15		(36)		5
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	20		(24)		16
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	15		(36)		5
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)	3
Actuarial (gain) loss	11
Total	14
Amortization from Balance Sheet: [Abstract]
Total	14
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	5		14		13
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	2		5		5
Louisville Gas And Electric Co [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	4		4		5
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	4		4		5
Kentucky Utilities Co [Member] | Pension Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	3	[3]	9	[3]	8	[3]
Kentucky Utilities Co [Member] | Other Postretirement Benefits United States [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense, excluding amounts charged to construction and other non-expense accounts	$ 2	[3]	$ 2	[3]	$ 3	[3]

[1] See Note 13 for details of a one-time voluntary retirement window offered to certain bargaining unit employees in 2014. 2013 and 2012 amounts are related to the WPD Midlands separations in the U.K.

[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.