Fair Value Measurements (Fair Value of Instruments Recorded at Carrying Amount) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Storm Fund Assets	$ 74	$ 75
Decommissioning Fund Investments, Fair Value	5,064	5,091
Available for sale debt securities amortized cost	1,823	1,906
Available-for-sale equity securities, amortized cost	$ 1,505	1,366
Special Use Funds Nuclear Decommissioning Funds Weighted Average Maturity	8 years
FPL [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	$ 10,020	9,388
Special Use Funds Storm Fund Assets	74	75
Decommissioning Fund Investments, Fair Value	3,430	3,449
Available for sale debt securities amortized cost	1,409	1,519
Available-for-sale equity securities, amortized cost	$ 732	664
Special Use Funds Nuclear Decommissioning Funds Weighted Average Maturity	8 years
Special Use Funds Storm Fund Weighted Average Maturity	3 years
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Special Use Funds Fair Value Disclosure	$ 675	567
Other Investments Primarily Notes Receivable Fair Value Disclosure	512	525
Long Term Debt Including Current Maturities Fair Value Disclosure	28,897	27,552
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	528	395
Long Term Debt Including Current Maturities Fair Value Disclosure	10,020	9,388
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	675	567
Other Investments Primarily Notes Receivable Fair Value Disclosure	722	679
Long Term Debt Including Current Maturities Fair Value Disclosure	30,412	30,013
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	18,031	19,973
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	528	395
Long Term Debt Including Current Maturities Fair Value Disclosure	11,028	$ 11,020
liabilities associated with assets held-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	$ 938