Fair Value Measurements (Fair Value of Instruments Recorded at Other than Fair Value) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	$ 892	$ 884
Other Investments Financial Instruments Fair Value Disclosure	30	54
Long Term Debt Including Current Maturities Fair Value Disclosure	39,667	29,498
Reported Value Measurement [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long Term Debt Including Current Maturities Fair Value Disclosure	463
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	891	883
Other Investments Financial Instruments Fair Value Disclosure	30	54
Long Term Debt Including Current Maturities Fair Value Disclosure	42,928	30,043
FPL[Member] | Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	706	693
Long Term Debt Including Current Maturities Fair Value Disclosure	14,161	11,783
FPL[Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	705	692
Long Term Debt Including Current Maturities Fair Value Disclosure	$ 16,448	$ 12,613