Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Condensed consolidated quarterly financial information [Abstract]
Operating revenues		$ 4,390	$ 4,416	$ 4,063	$ 3,857	$ 4,004	$ 4,803	$ 4,399	$ 3,967	$ 16,727	$ 17,173	[1]	$ 16,138	[1]
Operating income		1,107	968	1,146	1,059	186	1,350	1,276	2,362	4,280	5,173	[1]	4,459	[1]
Net income		314	941	687	3,834	2,072	856	804	1,591	5,776	5,323	[1],[2],[3]	2,999	[1],[2],[3]
Net income (loss) attributable to NEE		$ 422	$ 1,005	$ 781	$ 4,431	$ 2,158	$ 846	$ 793	$ 1,583	$ 6,638	$ 5,380	[1]	$ 2,906	[1]
Basic EPS - Net income (in dollars per share)		$ 0.88	$ 2.12	$ 1.66	$ 9.41	$ 4.59	$ 1.80	$ 1.70	$ 3.39	$ 14.03	$ 11.48	[1]	$ 6.27	[1]
Diluted EPS - Net income (in dollars per share)		0.88	2.10	1.61	9.32	4.55	1.79	1.68	3.37	13.88	11.39	[1]	6.24	[1]
Dividends per share of common stock (in dollars per share)		1.11	1.11	1.11	1.11	0.9825	0.9825	0.9825	0.9825	$ 4.44	$ 3.93		$ 3.48
High common stock sales price (in dollars per share)		184.20	175.65	169.53	164.41	159.40	151.60	144.87	133.28
Low common stock sales price (in dollars per share)		$ 164.78	$ 163.52	$ 155.06	$ 145.10	$ 145.62	$ 138.00	$ 127.09	$ 117.33
FPL[Member]
Condensed consolidated quarterly financial information [Abstract]
Operating revenues		$ 2,935	$ 3,399	$ 2,908	$ 2,620	$ 2,877	$ 3,477	$ 3,091	$ 2,527	$ 11,862	$ 11,972	[4]	$ 10,895	[4]
Operating income		609	917	921	707	617	1,022	940	811	3,154	3,390	[4]	3,161	[4]
Net income	[5]									$ 2,171	$ 1,880	[4],[6]	$ 1,727	[4],[6]
Net income (loss) attributable to NEE		$ 407	$ 654	$ 626	$ 484	$ 344	$ 566	$ 526	$ 445

[1] Amounts have been retrospectively adjusted as discussed in Note 14 and Note 3 - Amendments to Presentation of Retirement Benefits.

[2] Amounts have been retrospectively adjusted as discussed in Note 14.

[3] Amounts have been retrospectively adjusted as discussed in Note 14.

[4] Amounts have been retrospectively adjusted as discussed in Note 14.

[5] FPL's comprehensive income is the same as reported net income.

[6] Amounts have been retrospectively adjusted as discussed in Note 14.