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Stock-Based Compensation (Details) (USD $)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Aggregate disclosures [Abstract]      
Compensation expense $ 47,000,000 $ 33,000,000 $ 26,000,000
All Awards [Member]
     
Aggregate disclosures [Abstract]      
Unrecognized compensation expense 27,000,000    
Weighted-average period for recognition 2.1    
All Plans [Member] | Restricted Shares And Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 2,040,035    
Granted (in shares) 1,487,556    
Vested (in shares) (1,002,229)    
Forfeited (in shares) (21,592)    
Nonvested, end of period (in shares) 2,503,770 2,040,035  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 27.03    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 28.35 $ 25.25 $ 28.93
Weighted-average grant date fair value per share, vested (in dollars per share) $ 27.23    
Weighted-average grant date fair value per share, forfeited (in dollars per share) $ 27.69    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 27.73 $ 27.03  
Total fair value of units vested during the period 27,000,000 19,000,000 15,000,000
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
All Plans [Member] | Performance Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 398,609    
Granted (in shares) 322,771    
Forfeited (in shares) (127,177)    
Nonvested, end of period (in shares) 594,203 398,609  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 33.31    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 31.41 $ 29.67 $ 34.06
Weighted-average grant date fair value per share, forfeited (in dollars per share) $ 38.61    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 31.14 $ 33.31  
Period over which performance units fair value is recognized (in years) 3    
Award payout percentage of target award if PPL's performance is at or above the 85th percentile of the S&P Electric Utilities Index 200.00% 200.00% 200.00%
Award payout percentage of target award if PPL's performance is at or above the 50th percentile of the S&P Electric Utilities Index 100.00% 100.00% 100.00%
Award payout percentage of target award if PPL's performance is at or above 40th percentile of the S&P Electric Utilities Index 50.00% 50.00% 50.00%
Award payout percentage of target award if PPL's performance is below the 40th percentile of the S&P Electric Utilities Index   25.00%  
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
Risk-free interest rate 0.30% 1.00% 1.41%
Expected option life (in years) 3 3 3
Expected stock volatility 19.30% 23.40% 34.70%
All Plans [Member] | Stock Options [Member]
     
Aggregate disclosures [Abstract]      
Cash received from exercise of stock options 6,000,000    
Fair value assumptions and methodology [Abstract]      
Risk-free interest rate 1.13% 2.34% 2.52%
Expected option life (in years) 6.17 5.71 5.43
Expected stock volatility 20.60% 21.60% 28.57%
Dividend yield 5.00% 5.93% 5.61%
Stock option activity [Roll Forward]      
Outstanding at beginning of period (in shares) 7,530,198    
Granted (in shares) 1,948,550    
Exercised (in shares) (263,094)    
Forfeited (in shares) (81,109)    
Outstanding at end of period (in shares) 9,134,545 7,530,198  
Stock options - additional disclosures [Abstract]      
Period that performance goals are evaluated (in years) 3    
Period after which employee stock options become exercisable in installments (in years) 1    
Period after which, employee stock options expire (in years) 10    
Weighted-average exercise price per share at beginning of period (in dollars per share) $ 30.65    
Weighted average exercise price per share, granted (in dollars per share) $ 28.19    
Weighted average exercise price per share, exercised (in dollars per share) $ 23.22    
Weighted average exercise price per share, forfeited (in dollars per share) $ 28.43    
Weighted average exercise price per share at end of period (in dollars per share) $ 30.36 $ 30.65  
Weighted average remaining contractual term (in years) 6.3    
Aggregate total intrinsic value 9,000,000    
Options exercisable at end of period (in shares) 6,134,265    
Weighted average exercise price, options exercisable at end of period (in dollars per share) $ 31.70    
Weighted average remaining contractual term, options exercisable at end of period (in years) 5.7    
Aggregate total intrinsic value, options exercisable at end of period 6,000,000    
Weighted average grant date fair value of options granted (in dollars per share) $ 2.48 $ 2.47 $ 4.70
All Plans [Member] | All Awards [Member]
     
Aggregate disclosures [Abstract]      
Compensation expense 49,000,000 36,000,000 26,000,000
Income tax benefit 20,000,000 15,000,000 11,000,000
Incentive Compensation Plan [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 15,769,431 [1]    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00% [1]    
Annual grant limit options (in shares) 3,000,000 [1]    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
Incentive Compensation Plan [Member] | Stock Options [Member]
     
Stock options - additional disclosures [Abstract]      
Period after the date of grant that employee must be employed before stock option exercise date can be accelerated (in years) 1    
Stock Incentive Plan [Member]
     
Stock-Based Compensation [Line Items]      
Period after grant, employee stock options expire upon retirement (in years) 10    
Period after which, employee stock options expire upon retirement (in years) 5    
Maximum number of shares approved for awards under the plan (in shares) 10,000,000    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year       
Annual grant limit options (in shares) 2,000,000    
Annual grant limit for individual participants - performance based awards (in shares) 750,000    
Annual grant limit for individual participants - performance based awards 15,000,000    
Incentive Compensation Plan For Key Employees [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 14,199,796    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00%    
Annual grant limit options (in shares) 3,000,000    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
PPL Energy Supply LLC [Member] | All Awards [Member]
     
Aggregate disclosures [Abstract]      
Unrecognized compensation expense 11,000,000    
Weighted-average period for recognition 2.4    
PPL Energy Supply LLC [Member] | All Plans [Member] | Restricted Shares And Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 665,180    
Transferred (in shares) 62,320    
Granted (in shares) 564,020    
Vested (in shares) (219,124)    
Forfeited (in shares) (11,710)    
Nonvested, end of period (in shares) 1,060,686 665,180  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 27.30    
Weighted-average grant date fair value per share, transferred (in dollars per share) $ 28.66    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 28.29 $ 25.14 $ 29.49
Weighted-average grant date fair value per share, vested (in dollars per share) $ 27.04    
Weighted-average grant date fair value per share, forfeited (in dollars per share) $ 27.97    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 27.95 $ 27.30  
Total fair value of units vested during the period 6,000,000 6,000,000 7,000,000
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
PPL Energy Supply LLC [Member] | All Plans [Member] | Performance Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 75,067    
Transferred (in shares) 12,719    
Granted (in shares) 71,572    
Forfeited (in shares) (35,169)    
Nonvested, end of period (in shares) 124,189 75,067  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 33.00    
Weighted-average grant date fair value per share, transferred (in dollars per share) $ 34.15    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 31.40 $ 29.68 $ 34.16
Weighted-average grant date fair value per share, forfeited (in dollars per share) $ 38.90    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 31.26 $ 33.00  
Period over which performance units fair value is recognized (in years) 3    
Award payout percentage of target award if PPL's performance is at or above the 85th percentile of the S&P Electric Utilities Index 200.00% 200.00% 200.00%
Award payout percentage of target award if PPL's performance is at or above the 50th percentile of the S&P Electric Utilities Index 100.00% 100.00% 100.00%
Award payout percentage of target award if PPL's performance is at or above 40th percentile of the S&P Electric Utilities Index 50.00% 50.00% 50.00%
Award payout percentage of target award if PPL's performance is below the 40th percentile of the S&P Electric Utilities Index   25.00%  
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
Risk-free interest rate 0.30% 1.00% 1.41%
Expected option life (in years) 3 3 3
Expected stock volatility 19.30% 23.40% 34.70%
PPL Energy Supply LLC [Member] | All Plans [Member] | Stock Options [Member]
     
Fair value assumptions and methodology [Abstract]      
Risk-free interest rate 1.13% 2.34% 2.52%
Expected option life (in years) 6.17 5.71 5.43
Expected stock volatility 20.60% 21.60% 28.57%
Dividend yield 5.00% 5.93% 5.61%
Stock option activity [Roll Forward]      
Outstanding at beginning of period (in shares) 1,690,153    
Transferred (in shares) 176,070    
Granted (in shares) 483,740    
Exercised (in shares) (36,358)    
Forfeited (in shares) (48,482)    
Outstanding at end of period (in shares) 2,265,123 1,690,153  
Stock options - additional disclosures [Abstract]      
Period that performance goals are evaluated (in years) 3    
Period after which employee stock options become exercisable in installments (in years) 1    
Period after which, employee stock options expire (in years) 10    
Weighted-average exercise price per share at beginning of period (in dollars per share) $ 30.79    
Weighted average exercise price per share, transferred (in dollars per share) $ 31.90    
Weighted average exercise price per share, granted (in dollars per share) $ 28.19    
Weighted average exercise price per share, exercised (in dollars per share) $ 24.35    
Weighted average exercise price per share, forfeited (in dollars per share) $ 29.34    
Weighted average exercise price per share at end of period (in dollars per share) $ 30.45 $ 30.79  
Weighted average remaining contractual term (in years) 6.1    
Aggregate total intrinsic value 2,000,000    
Options exercisable at end of period (in shares) 1,529,711    
Weighted average exercise price, options exercisable at end of period (in dollars per share) $ 31.80    
Weighted average remaining contractual term, options exercisable at end of period (in years) 4.9    
Aggregate total intrinsic value, options exercisable at end of period 1,000,000    
Weighted average grant date fair value of options granted (in dollars per share) $ 2.51 $ 2.47 $ 4.73
PPL Energy Supply LLC [Member] | All Plans [Member] | All Awards [Member]
     
Aggregate disclosures [Abstract]      
Compensation expense 23,000,000 16,000,000 20,000,000
Income tax benefit 10,000,000 6,000,000 8,000,000
PPL Energy Supply LLC [Member] | Incentive Compensation Plan [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 15,769,431 [1]    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00% [1]    
Annual grant limit options (in shares) 3,000,000 [1]    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
PPL Energy Supply LLC [Member] | Incentive Compensation Plan [Member] | Stock Options [Member]
     
Stock options - additional disclosures [Abstract]      
Period after the date of grant that employee must be employed before stock option exercise date can be accelerated (in years) 1    
PPL Energy Supply LLC [Member] | Stock Incentive Plan [Member]
     
Stock-Based Compensation [Line Items]      
Period after grant, employee stock options expire upon retirement (in years) 10    
Period after which, employee stock options expire upon retirement (in years) 5    
Maximum number of shares approved for awards under the plan (in shares) 10,000,000    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year       
Annual grant limit options (in shares) 2,000,000    
Annual grant limit for individual participants - performance based awards (in shares) 750,000    
Annual grant limit for individual participants - performance based awards 15,000,000    
PPL Energy Supply LLC [Member] | Incentive Compensation Plan For Key Employees [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 14,199,796    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00%    
Annual grant limit options (in shares) 3,000,000    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
PPL Electric Utilities Corp [Member] | All Awards [Member]
     
Aggregate disclosures [Abstract]      
Unrecognized compensation expense 2,000,000    
Weighted-average period for recognition 2.2    
PPL Electric Utilities Corp [Member] | All Plans [Member] | Restricted Shares And Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 251,595    
Transferred (in shares) (54,460)    
Granted (in shares) 133,530    
Vested (in shares) (61,995)    
Forfeited (in shares) (7,442)    
Nonvested, end of period (in shares) 261,228 251,595  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 27.10    
Weighted-average grant date fair value per share, transferred (in dollars per share) $ 28.93    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 28.51 $ 25.09 $ 29.40
Weighted-average grant date fair value per share, vested (in dollars per share) $ 27.63    
Weighted-average grant date fair value per share, forfeited (in dollars per share) $ 27.46    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 27.30 $ 27.10  
Total fair value of units vested during the period 2,000,000 2,000,000 2,000,000
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
PPL Electric Utilities Corp [Member] | All Plans [Member] | Performance Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 32,808    
Transferred (in shares) (12,719)    
Granted (in shares) 16,234    
Forfeited (in shares) (10,240)    
Nonvested, end of period (in shares) 26,083 32,808  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 33.11    
Weighted-average grant date fair value per share, transferred (in dollars per share) $ 34.15    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 31.37 $ 29.57 $ 33.54
Weighted-average grant date fair value per share, forfeited (in dollars per share) $ 34.17    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 31.10 $ 33.11  
Period over which performance units fair value is recognized (in years) 3    
Award payout percentage of target award if PPL's performance is at or above the 85th percentile of the S&P Electric Utilities Index 200.00% 200.00% 200.00%
Award payout percentage of target award if PPL's performance is at or above the 50th percentile of the S&P Electric Utilities Index 100.00% 100.00% 100.00%
Award payout percentage of target award if PPL's performance is at or above 40th percentile of the S&P Electric Utilities Index 50.00% 50.00% 50.00%
Award payout percentage of target award if PPL's performance is below the 40th percentile of the S&P Electric Utilities Index   25.00%  
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
Risk-free interest rate 0.30% 1.00% 1.41%
Expected option life (in years) 3 3 3
Expected stock volatility 19.30% 23.40% 34.70%
PPL Electric Utilities Corp [Member] | All Plans [Member] | Stock Options [Member]
     
Fair value assumptions and methodology [Abstract]      
Risk-free interest rate 1.13% 2.34% 2.52%
Expected option life (in years) 6.17 5.71 5.43
Expected stock volatility 20.60% 21.60% 28.57%
Dividend yield 5.00% 5.93% 5.61%
Stock option activity [Roll Forward]      
Outstanding at beginning of period (in shares) 460,510    
Transferred (in shares) (176,070)    
Granted (in shares) 100,590    
Exercised (in shares) (11,873)    
Forfeited (in shares) (32,627)    
Outstanding at end of period (in shares) 340,530 460,510  
Stock options - additional disclosures [Abstract]      
Period that performance goals are evaluated (in years) 3    
Period after which employee stock options become exercisable in installments (in years) 1    
Period after which, employee stock options expire (in years) 10    
Weighted-average exercise price per share at beginning of period (in dollars per share) $ 31.05    
Weighted average exercise price per share, transferred (in dollars per share) $ 31.90    
Weighted average exercise price per share, granted (in dollars per share) $ 28.22    
Weighted average exercise price per share, exercised (in dollars per share) $ 25.67    
Weighted average exercise price per share, forfeited (in dollars per share) $ 27.07    
Weighted average exercise price per share at end of period (in dollars per share) $ 30.35 $ 31.05  
Weighted average remaining contractual term (in years) 7.0    
Options exercisable at end of period (in shares) 193,355    
Weighted average exercise price, options exercisable at end of period (in dollars per share) $ 32.43    
Weighted average remaining contractual term, options exercisable at end of period (in years) 5.8    
Weighted average grant date fair value of options granted (in dollars per share) $ 2.50 $ 2.47 $ 4.62
PPL Electric Utilities Corp [Member] | All Plans [Member] | All Awards [Member]
     
Aggregate disclosures [Abstract]      
Compensation expense 11,000,000 8,000,000 6,000,000
Income tax benefit 4,000,000 3,000,000 3,000,000
PPL Electric Utilities Corp [Member] | Incentive Compensation Plan [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 15,769,431 [1]    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00% [1]    
Annual grant limit options (in shares) 3,000,000 [1]    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
PPL Electric Utilities Corp [Member] | Incentive Compensation Plan [Member] | Stock Options [Member]
     
Stock options - additional disclosures [Abstract]      
Period after the date of grant that employee must be employed before stock option exercise date can be accelerated (in years) 1    
PPL Electric Utilities Corp [Member] | Stock Incentive Plan [Member]
     
Stock-Based Compensation [Line Items]      
Period after grant, employee stock options expire upon retirement (in years) 10    
Period after which, employee stock options expire upon retirement (in years) 5    
Maximum number of shares approved for awards under the plan (in shares) 10,000,000    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year       
Annual grant limit options (in shares) 2,000,000    
Annual grant limit for individual participants - performance based awards (in shares) 750,000    
Annual grant limit for individual participants - performance based awards 15,000,000    
PPL Electric Utilities Corp [Member] | Incentive Compensation Plan For Key Employees [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 14,199,796    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00%    
Annual grant limit options (in shares) 3,000,000    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
LG And E And KU Energy LLC [Member] | All Awards [Member]
     
Aggregate disclosures [Abstract]      
Unrecognized compensation expense 2,000,000    
Weighted-average period for recognition 1.8    
LG And E And KU Energy LLC [Member] | All Plans [Member] | Restricted Shares And Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 145,210    
Granted (in shares) 144,340    
Vested (in shares) (149,910)    
Nonvested, end of period (in shares) 139,640 145,210  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 26.31    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 28.34    $ 26.31
Weighted-average grant date fair value per share, vested (in dollars per share) $ 26.38    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 28.34 $ 26.31  
Total fair value of units vested during the period 4,000,000 1,000,000   
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
LG And E And KU Energy LLC [Member] | All Plans [Member] | Performance Units [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Nonvested, beginning of period (in shares) 26,893    
Granted (in shares) 55,857    
Nonvested, end of period (in shares) 82,750 26,893  
Awards, other than equity based, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) $ 29.20    
Weighted-average grant date fair value per share, granted (in dollars per share) $ 31.30 $ 29.20   
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) $ 30.62 $ 29.20  
Period over which performance units fair value is recognized (in years) 3    
Award payout percentage of target award if PPL's performance is at or above the 85th percentile of the S&P Electric Utilities Index 200.00% 200.00% 200.00%
Award payout percentage of target award if PPL's performance is at or above the 50th percentile of the S&P Electric Utilities Index 100.00% 100.00% 100.00%
Award payout percentage of target award if PPL's performance is at or above 40th percentile of the S&P Electric Utilities Index 50.00% 50.00% 50.00%
Award payout percentage of target award if PPL's performance is below the 40th percentile of the S&P Electric Utilities Index   25.00%  
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 3 3
Risk-free interest rate 0.30% 1.00% 1.41%
Expected option life (in years) 3 3 3
Expected stock volatility 19.30% 23.40% 34.70%
LG And E And KU Energy LLC [Member] | All Plans [Member] | Stock Options [Member]
     
Fair value assumptions and methodology [Abstract]      
Risk-free interest rate 1.13% 2.34% 2.52%
Expected option life (in years) 6.17 5.71 5.43
Expected stock volatility 20.60% 21.60% 28.57%
Dividend yield 5.00% 5.93% 5.61%
Stock option activity [Roll Forward]      
Outstanding at beginning of period (in shares) 329,600    
Granted (in shares) 354,490    
Exercised (in shares) (49,243)    
Outstanding at end of period (in shares) 634,847 329,600  
Stock options - additional disclosures [Abstract]      
Period that performance goals are evaluated (in years) 3    
Period after which employee stock options become exercisable in installments (in years) 1    
Period after which, employee stock options expire (in years) 10    
Weighted-average exercise price per share at beginning of period (in dollars per share) $ 25.77    
Weighted average exercise price per share, granted (in dollars per share) $ 28.17    
Weighted average exercise price per share, exercised (in dollars per share) $ 25.74    
Weighted average exercise price per share at end of period (in dollars per share) $ 27.11 $ 25.77  
Weighted average remaining contractual term (in years) 8.6    
Aggregate total intrinsic value 1,000,000    
Options exercisable at end of period (in shares) 144,260    
Weighted average exercise price, options exercisable at end of period (in dollars per share) $ 26.62    
Weighted average remaining contractual term, options exercisable at end of period (in years) 8.4    
Weighted average grant date fair value of options granted (in dollars per share) $ 2.51 $ 2.47   
LG And E And KU Energy LLC [Member] | All Plans [Member] | All Awards [Member]
     
Aggregate disclosures [Abstract]      
Compensation expense 8,000,000 5,000,000   
Income tax benefit 4,000,000 2,000,000   
LG And E And KU Energy LLC [Member] | Incentive Compensation Plan [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 15,769,431 [1]    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00% [1]    
Annual grant limit options (in shares) 3,000,000 [1]    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
LG And E And KU Energy LLC [Member] | Incentive Compensation Plan [Member] | Stock Options [Member]
     
Stock options - additional disclosures [Abstract]      
Period after the date of grant that employee must be employed before stock option exercise date can be accelerated (in years) 1    
LG And E And KU Energy LLC [Member] | Stock Incentive Plan [Member]
     
Stock-Based Compensation [Line Items]      
Period after grant, employee stock options expire upon retirement (in years) 10    
Period after which, employee stock options expire upon retirement (in years) 5    
Maximum number of shares approved for awards under the plan (in shares) 10,000,000    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year       
Annual grant limit options (in shares) 2,000,000    
Annual grant limit for individual participants - performance based awards (in shares) 750,000    
Annual grant limit for individual participants - performance based awards 15,000,000    
LG And E And KU Energy LLC [Member] | Incentive Compensation Plan For Key Employees [Member]
     
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 14,199,796    
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year 2.00%    
Annual grant limit options (in shares) 3,000,000    
Annual grant limit for individual participants - performance based awards (in shares)       
Annual grant limit for individual participants - performance based awards       
[1] Applicable to outstanding awards granted from January 27, 2006 to January 26, 2012. During 2012, the total plan award limit was reached and the ICP was replaced by the SIP.