Fair Value Measurements (Fair Value of Instruments Recorded at Other than Fair Value) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Storm Fund Assets	$ 0	$ 74
Decommissioning Fund Investments, Fair Value	5,434	5,064
Available for sale debt securities amortized cost	1,820	1,823
Available-for-sale equity securities, amortized cost	$ 1,543	1,505
Special Use Funds Nuclear Decommissioning Funds Weighted Average Maturity	9 years
FPL [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	$ 10,072	10,020
Decommissioning Fund Investments, Fair Value	3,665	3,430
Available for sale debt securities amortized cost	1,373	1,409
Available-for-sale equity securities, amortized cost	$ 764	732
Special Use Funds Nuclear Decommissioning Funds Weighted Average Maturity	9 years
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	$ 712	675
Other Investments Primarily Notes Receivable Fair Value Disclosure	526	512
Long Term Debt Including Current Maturities Fair Value Disclosure	30,418	28,897
Reported Value Measurement [Member] | FPL [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	557	528
Long Term Debt Including Current Maturities Fair Value Disclosure	10,072	10,020
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	712	675
Other Investments Primarily Notes Receivable Fair Value Disclosure	668	722
Long Term Debt Including Current Maturities Fair Value Disclosure	31,623	30,412
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long Term Debt Including Current Maturities Fair Value Disclosure	29,804	18,031
Estimate of Fair Value Measurement [Member] | FPL [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	557	528
Long Term Debt Including Current Maturities Fair Value Disclosure	11,211	11,028
liabilities associated with assets held-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	$ 373	$ 938