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Stock-Based Compensation (Details)
12 Months Ended
Dec. 31, 2017
USD ($)
Integer
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Dec. 31, 2015
USD ($)
$ / shares
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) 1,337,025    
Granted (in shares) 538,441    
Vested (in shares) (567,001)    
Forfeited (in shares) (16,816)    
Nonvested, end of period (in shares) 1,291,649 1,337,025  
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares $ 31.57    
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares 35.30 $ 33.84 $ 34.50
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares 29.28    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 34.28    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 34.10 $ 31.57  
Total fair value of units vested during the period | $ $ 20,000,000 $ 30,000,000 $ 28,000,000
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 years 3 years 3 years
All Plans [Member] | Restricted Shares And Units [Member] | PPL Energy Supply Spinoff [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Vested (in shares) (252,850)    
All Plans [Member] | Total Shareowner Return 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) 1,070,536    
Granted (in shares) 293,642    
Vested (in shares) (243,983)    
Forfeited (in shares) (141,964)    
Nonvested, end of period (in shares) 978,231 1,070,536  
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares $ 34.65    
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares 38.38 $ 35.74 $ 36.76
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares 32.42    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 32.27    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 36.67 $ 34.65  
Total fair value of units vested during the period | $ $ 8,000,000 $ 12,000,000 $ 6,000,000
Period over which performance units fair value is recognized (in years) 3 years 3 years 3 years
Maximum payout percentage of target award 200.00% 200.00% 200.00%
Fair value assumptions and methodology [Abstract]      
Expected option life (in years) 3 years 3 years 3 years
Expected stock volatility 17.40% 19.60% 15.90%
All Plans [Member] | Total Shareowner Return Performance Units [Member] | PPL Energy Supply Spinoff [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Vested (in shares) (41,405)    
All Plans [Member] | Total Shareowner Return Performance Units [Member] | Retirement Eligible [Member]      
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Period over which performance units fair value is recognized (in years) 1 year 1 year 1 year
All Plans [Member] | Total Shareowner Return Performance Units [Member] | Not Retirement Eligible [Member]      
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Period over which performance units fair value is recognized (in years) 3 years 3 years 3 years
Minimum period after which employee stock options become exercisable (in years) 1 year 1 year 1 year
All Plans [Member] | Return On Equity Performance Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Granted (in shares) 97,925    
Forfeited (in shares) (997)    
Nonvested, end of period (in shares) 96,928    
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares $ 34.42    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 34.41    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 34.42    
Period over which performance units fair value is recognized (in years) 3 years    
Maximum payout percentage of target award 200.00%    
All Plans [Member] | Stock Options [Member]      
Stock option activity [Roll Forward]      
Outstanding at beginning of period (in shares) 4,481,160    
Exercised (in shares) (718,977)    
Outstanding at end of period (in shares) 3,762,183 4,481,160  
Stock options - additional disclosures [Abstract]      
Period after which, employee stock options expire (in years) 10 years    
Weighted-average exercise price per share at beginning of period (in dollars per share) | $ / shares $ 28.98    
Weighted average exercise price per share, exercised (in dollars per share) | $ / shares 26.67    
Weighted average exercise price per share at end of period (in dollars per share) | $ / shares $ 29.42 $ 28.98  
Weighted average remaining contractual term (in years) 3 years 6 months    
Aggregate total intrinsic value | $ $ 14,000,000    
Cash received from exercise of stock options | $ 19,000,000 $ 52,000,000 $ 97,000,000
Total intrinsic value of stock options exercised | $ 8,000,000 18,000,000 21,000,000
All Plans [Member] | All Awards [Member]      
Aggregate disclosures [Abstract]      
Compensation expense | $ 32,000,000 27,000,000 33,000,000
Income tax benefit | $ 13,000,000 $ 12,000,000 $ 14,000,000
Unrecognized compensation expense | $ $ 10,000,000    
Weighted-average period for recognition | Integer 1.7    
Stock Incentive Plan [Member]      
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 15,000,000    
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    
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) 204,570    
Transfer between registrants (5,250)    
Granted (in shares) 79,321    
Vested (in shares) (91,117)    
Forfeited (in shares) (3,108)    
Nonvested, end of period (in shares) 184,416 204,570  
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares $ 31.27    
Weighted-average grant date fair value per share, transfer between registrants (in dollars per share) | $ / shares 32.05    
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares 35.45 $ 34.32 $ 34.41
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares 28.83    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 34.68    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 34.20 $ 31.27  
Total fair value of units vested during the period | $ $ 3,000,000 $ 3,000,000 $ 4,000,000
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 years 3 years 3 years
PPL Electric Utilities Corp [Member] | All Plans [Member] | Total Shareowner Return 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) 76,726    
Granted (in shares) 26,086    
Vested (in shares) (14,713)    
Forfeited (in shares) (12,586)    
Nonvested, end of period (in shares) 75,513 76,726  
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares $ 34.68    
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares 38.37 $ 35.68 $ 37.93
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares 32.14    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 35.45    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 37.00 $ 34.68  
Period over which performance units fair value is recognized (in years) 3 years 3 years 3 years
Maximum payout percentage of target award 200.00% 200.00% 200.00%
PPL Electric Utilities Corp [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Retirement Eligible [Member]      
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Period over which performance units fair value is recognized (in years) 1 year 1 year 1 year
PPL Electric Utilities Corp [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Not Retirement Eligible [Member]      
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Period over which performance units fair value is recognized (in years) 3 years 3 years 3 years
Minimum period after which employee stock options become exercisable (in years) 1 year 1 year 1 year
PPL Electric Utilities Corp [Member] | All Plans [Member] | Return On Equity Performance Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Granted (in shares) 8,696    
Nonvested, end of period (in shares) 8,696    
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares $ 34.41    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 34.41    
Period over which performance units fair value is recognized (in years) 3 years    
Maximum payout percentage of target award 200.00%    
PPL Electric Utilities Corp [Member] | All Plans [Member] | Performance Units [Member]      
Fair value assumptions and methodology [Abstract]      
Expected option life (in years) 3 years 3 years 3 years
Expected stock volatility 17.40% 19.60% 15.90%
PPL Electric Utilities Corp [Member] | All Plans [Member] | Stock Options [Member]      
Stock option activity [Roll Forward]      
Outstanding at beginning of period (in shares) 240,939    
Exercised (in shares) (42,659)    
Outstanding at end of period (in shares) 198,280 240,939  
Stock options - additional disclosures [Abstract]      
Period after which, employee stock options expire (in years) 10 years    
Weighted-average exercise price per share at beginning of period (in dollars per share) | $ / shares $ 27.48    
Weighted average exercise price per share, exercised (in dollars per share) | $ / shares 26.99    
Weighted average exercise price per share at end of period (in dollars per share) | $ / shares $ 27.58 $ 27.48  
Weighted average remaining contractual term (in years) 3 years 9 months    
Aggregate total intrinsic value, options exercisable at end of period | $ $ 1,000,000    
PPL Electric Utilities Corp [Member] | All Plans [Member] | All Awards [Member]      
Aggregate disclosures [Abstract]      
Compensation expense | $ 18,000,000 $ 16,000,000 $ 14,000,000
Income tax benefit | $ 8,000,000 $ 7,000,000 $ 6,000,000
Unrecognized compensation expense | $ $ 2,000,000    
Weighted-average period for recognition | Integer 1.7    
PPL Electric Utilities Corp [Member] | Stock Incentive Plan [Member]      
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 15,000,000    
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    
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) 243,281    
Transfer between registrants 25,337    
Granted (in shares) 97,775    
Vested (in shares) (125,612)    
Forfeited (in shares) (9,224)    
Nonvested, end of period (in shares) 231,557 243,281  
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares $ 31.53    
Weighted-average grant date fair value per share, transfer between registrants (in dollars per share) | $ / shares 31.61    
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares 35.25 $ 33.73 $ 34.89
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares 29.68    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 34.04    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 34.01 $ 31.53  
Total fair value of units vested during the period | $ $ 4,000,000 $ 5,000,000 $ 4,000,000
Fair value assumptions and methodology [Abstract]      
Award vesting period (in years) 3 years 3 years 3 years
LG And E And KU Energy LLC [Member] | All Plans [Member] | Total Shareowner Return 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) 191,601    
Transfer between registrants 8,307    
Granted (in shares) 64,555    
Vested (in shares) (48,980)    
Forfeited (in shares) (35,194)    
Nonvested, end of period (in shares) 180,289 191,601  
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares $ 34.34    
Weighted-average grant date fair value per share, transfer between registrants (in dollars per share) | $ / shares 35.96    
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares 38.24 $ 35.28 $ 37.10
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares 32.09    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 35.25    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 36.69 $ 34.34  
Period over which performance units fair value is recognized (in years) 3 years 3 years 3 years
Maximum payout percentage of target award 200.00% 200.00% 200.00%
LG And E And KU Energy LLC [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Retirement Eligible [Member]      
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Period over which performance units fair value is recognized (in years) 1 year 1 year 1 year
LG And E And KU Energy LLC [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Not Retirement Eligible [Member]      
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Period over which performance units fair value is recognized (in years) 3 years 3 years 3 years
Minimum period after which employee stock options become exercisable (in years) 1 year 1 year 1 year
LG And E And KU Energy LLC [Member] | All Plans [Member] | Return On Equity Performance Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]      
Granted (in shares) 21,536    
Forfeited (in shares) (997)    
Nonvested, end of period (in shares) 20,539    
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]      
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares $ 34.29    
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares 34.41    
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares $ 34.29    
Period over which performance units fair value is recognized (in years) 3 years    
Maximum payout percentage of target award 200.00%    
LG And E And KU Energy LLC [Member] | All Plans [Member] | Performance Units [Member]      
Fair value assumptions and methodology [Abstract]      
Expected option life (in years) 3 years 3 years 3 years
Expected stock volatility 17.40% 19.60% 15.90%
LG And E And KU Energy LLC [Member] | All Plans [Member] | Stock Options [Member]      
Stock option activity [Roll Forward]      
Outstanding at beginning of period (in shares) 61,896    
Exercised (in shares) (28,164)    
Outstanding at end of period (in shares) 33,732 61,896  
Stock options - additional disclosures [Abstract]      
Period after which, employee stock options expire (in years) 10 years    
Weighted-average exercise price per share at beginning of period (in dollars per share) | $ / shares $ 25.81    
Weighted average exercise price per share, exercised (in dollars per share) | $ / shares 26.59    
Weighted average exercise price per share at end of period (in dollars per share) | $ / shares $ 25.15 $ 25.81  
Weighted average remaining contractual term (in years) 4 years 1 month    
Aggregate total intrinsic value, options exercisable at end of period | $ $ 0    
LG And E And KU Energy LLC [Member] | All Plans [Member] | All Awards [Member]      
Aggregate disclosures [Abstract]      
Compensation expense | $ 8,000,000 $ 7,000,000 $ 8,000,000
Income tax benefit | $ 3,000,000 $ 3,000,000 $ 3,000,000
Unrecognized compensation expense | $ $ 1,000,000    
Weighted-average period for recognition | Integer 1.6    
LG And E And KU Energy LLC [Member] | Stock Incentive Plan [Member]      
Stock-Based Compensation [Line Items]      
Maximum number of shares approved for awards under the plan (in shares) 15,000,000    
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