XML 61 R48.htm IDEA: XBRL DOCUMENT v3.20.1
Fair Value Measurements (Narrative) (Details) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2020
Dec. 31, 2019
Assets, Fair Value Disclosure $ 0 $ 0
Gain (loss) recognized 0  
Liabilities, Fair Value Disclosure 0 0
Asset Impairment Charges   369,000,000
Renewable Energy [Member]    
Decrease in liability   20,000,000
Gain (loss) recognized   21,000,000
HSG [Member]    
Asset Impairment Charges $ 0 $ 916,000,000