XML 92 R57.htm IDEA: XBRL DOCUMENT v3.8.0.1
Derivative Instruments (Credit Risk Disclosures) (Details) - USD ($)
Dec. 31, 2017
Dec. 31, 2016
Derivative [Line Items]    
Liability position of derivative $ 1,100,000,000 $ 1,300,000,000
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Bbb Or Baa2 145,000,000 110,000,000
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Below Investment Grade 1,200,000,000 990,000,000
Additional Collateral Aggregate Fair Value Due To Other Financial Measures 210,000,000 225,000,000
Collateral Already Posted, Aggregate Fair Value 2,000,000 1,000,000
Letters Of Credit Already Posted Aggregate Fair Value 20,000,000 30,000,000
FPL[Member]    
Derivative [Line Items]    
Liability position of derivative 3,000,000 5,000,000
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Bbb Or Baa2 0 0
Additional Collateral Aggregate Fair Value Due To Credit Rating Downgrade To Below Investment Grade 45,000,000 10,000,000
Additional Collateral Aggregate Fair Value Due To Other Financial Measures 95,000,000 115,000,000
Collateral Already Posted, Aggregate Fair Value 0 0
Letters Of Credit Already Posted Aggregate Fair Value $ 0 $ 0