Summary of Significant Accounting and Reporting Policies (Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current:
Derivatives	$ 0	$ 218
Storm reserve deficiency	203	0
Other	321	285
Total	524	503
Noncurrent:
Purchased power agreement termination	636	726
Other	1,258	1,052
Total	1,894	1,778
Current:
Derivatives	208	0
Other	91	14
Total	299	14
Noncurrent:
Accrued asset removal costs	1,956	1,930
Asset retirement obligation regulatory expense difference	2,294	2,182
Other	656	494
Total	4,906	4,606
FPL [Member]
Current:
Derivatives	0	218
Storm reserve deficiency	203	0
Other	321	284
Total	524	502
Noncurrent:
Purchased power agreement termination	636	726
Other	937	787
Total	1,573	1,513
Current:
Derivatives	208	0
Other	86	12
Total	294	12
Noncurrent:
Accrued asset removal costs	1,944	1,921
Asset retirement obligation regulatory expense difference	2,294	2,182
Other	655	492
Total	$ 4,893	$ 4,595