XML 49 R36.htm IDEA: XBRL DOCUMENT v3.7.0.1
Organization and Basis of Presentation (Details Textuals)
mi in Thousands, customer in Millions, MWh in Millions
 1 Months Ended 2 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Jul. 27, 2017
USD ($)
limited_guaranty
Natural_gas_plant
MW
Mar. 31, 2017
MWh
Mar. 06, 2017
MWh
MW
Jun. 30, 2017
USD ($)
transmission_center
MW
Jun. 30, 2016
USD ($)
Jun. 30, 2017
USD ($)
customer
transmission_center
company
mi
MW
Jun. 30, 2016
USD ($)
Dec. 31, 2018
MWh
Dec. 31, 2017
MWh
Dec. 31, 2016
USD ($)
MWh
Dec. 31, 2020
MW
Mar. 07, 2017
USD ($)
MW
Dec. 31, 2015
MW
Property, Plant and Equipment [Line Items]                          
Aggregate amount of capacity | MW           17,000              
Length of transmission lines | mi           24              
Number of regional transmission centers | transmission_center       2   2              
Capitalized cost of equity       $ 9,000,000   $ 17,000,000              
Capitalized interest       $ 11,000,000 $ 17,000,000 23,000,000 $ 34,000,000            
Impairment of assets         647,000,000                
Net cash used in operating activities           (1,482,000,000) (1,472,000,000)            
Net cash provided by financing activities           $ (56,000,000) 363,000,000            
Accounting Standards Update 2016-09                          
Property, Plant and Equipment [Line Items]                          
Net cash used in operating activities                   $ 12,000,000      
Net cash provided by financing activities                   12,000,000      
Accounting Standards Update 2016-09 | Retained Earnings                          
Property, Plant and Equipment [Line Items]                          
Cumulative effect of new accounting principle                   $ 6,000,000      
Regulated Distribution                          
Property, Plant and Equipment [Line Items]                          
Number of existing utility operating companies | company           10              
Number of customers served by utility operating companies | customer           6              
Plant capacity (in MW's) | MW       3,790   3,790              
CES                          
Property, Plant and Equipment [Line Items]                          
Capacity in deactivated power plants (in MW's) | MW                         6,770
Impairment of assets       $ 131,000,000                  
Plant capacity (in MW's) | MW     13,000 13,162   13,162           10,000  
Purchase power agreements additional capacity (in MWh) | MWh     5                    
Contract sales (in MWh) | MWh                   53      
FES                          
Property, Plant and Equipment [Line Items]                          
Impairment of assets         $ 517,000,000                
Net cash used in operating activities           $ (295,000,000) (557,000,000)            
Net cash provided by financing activities           7,000,000 $ (38,000,000)            
FES | CES                          
Property, Plant and Equipment [Line Items]                          
Inability to extend or refinance debt next year       $ 515,000,000   515,000,000              
Scenario, Forecast | CES                          
Property, Plant and Equipment [Line Items]                          
Capacity in deactivated power plants (in MW's) | MW                     856    
Minimum | CES                          
Property, Plant and Equipment [Line Items]                          
Annual generation capacity (in MW) | MWh   60 70                    
Minimum | Scenario, Forecast | CES                          
Property, Plant and Equipment [Line Items]                          
Expected contract sales (in MWh) | MWh               35 40        
Maximum | CES                          
Property, Plant and Equipment [Line Items]                          
Annual generation capacity (in MW) | MWh   65 75                    
Maximum | Scenario, Forecast | CES                          
Property, Plant and Equipment [Line Items]                          
Expected contract sales (in MWh) | MWh               40 45        
Line of Credit | Revolving Credit Facility                          
Property, Plant and Equipment [Line Items]                          
Maximum amount borrowed under revolving credit facility       $ 500,000,000   $ 500,000,000              
Pleasants Power Station                          
Property, Plant and Equipment [Line Items]                          
Plant capacity (in MW's) | MW                       1,300  
Pleasants Power Station | CES                          
Property, Plant and Equipment [Line Items]                          
Plant capacity (in MW's) | MW       1,300   1,300              
Held-for-sale | Pleasants Power Station                          
Property, Plant and Equipment [Line Items]                          
Assets held for sale                       $ 195,000,000  
Subsequent Event | Purchase Agreement with Aspen Generating, LLC                          
Property, Plant and Equipment [Line Items]                          
Plant capacity (in MW's) | MW 1,572                        
Cash purchase price $ 925,000,000                        
Number of limited guaranties | limited_guaranty 2                        
Subsequent Event | Purchase Agreement with Aspen Generating, LLC | AE Supply                          
Property, Plant and Equipment [Line Items]                          
Number of gas generating plants | Natural_gas_plant 4                        
Discharge of note indenture $ 305,000,000                        
Make-whole premiums $ 100,000,000                        
Subsequent Event | Purchase Agreement with Aspen Generating, LLC | AGC                          
Property, Plant and Equipment [Line Items]                          
Ownership percentage 59.00%