XML 201 R52.htm IDEA: XBRL DOCUMENT v3.20.4
PROPERTY, PLANT AND EQUIPMENT - Summary (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
PROPERTY, PLANT AND EQUIPMENT    
Cost $ 2,997 $ 2,715
Accumulated Depreciation (1,250) (1,187)
Net Book Value 1,747 1,528
Pipeline    
PROPERTY, PLANT AND EQUIPMENT    
Cost 1,910 1,907
Accumulated Depreciation (982) (929)
Net Book Value 928 978
Compression    
PROPERTY, PLANT AND EQUIPMENT    
Cost 730 584
Accumulated Depreciation (210) (202)
Net Book Value 520 382
Metering and other    
PROPERTY, PLANT AND EQUIPMENT    
Cost 208 180
Accumulated Depreciation (58) (56)
Net Book Value 150 124
Payment to acquire commercial system 26  
Metering and other | Great Lakes Gas Transmissions Limited Partnership    
PROPERTY, PLANT AND EQUIPMENT    
Payment to acquire commercial system 12  
Construction in progress    
PROPERTY, PLANT AND EQUIPMENT    
Cost 149 44
Net Book Value $ 149 $ 44