Debt (Schedule of Debt Instruments) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Less current maturities of long-term debt	$ 2,716	$ 1,673	[1]
Long-term debt, excluding current maturities	26,782	31,410	[1]
Variable rate tax exempt bonds	893
Repayment prior to maturity	2,389
FPL[Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs and discount	(132)	(105)
Total long-term debt	11,783	11,651
Less current maturities of long-term debt	95	464	[2]
Long-term debt, excluding current maturities	11,688	11,187	[2]
Repayment prior to maturity	95
FPL[Member] | First mortgage bonds - fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 10,626	$ 9,145
Weighted-average interest rate	4.60%	4.70%
FPL[Member] | Storm-recovery bonds - fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 74	$ 144
Weighted-average interest rate	5.26%	5.26%
FPL[Member] | Pollution control, solid waste disposal and industrial development revenue bonds - primary variable [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,022	$ 966
Weighted-average interest rate	2.04%	2.12%
FPL[Member] | Senior Unsecured Notes - Variable [Domain]
Debt Instrument [Line Items]
Long-term debt, gross	$ 193	$ 0
Weighted-average interest rate	2.40%
Repayment prior to maturity	$ 94
FPL[Member] | Other long-term debt - variable [Member]
Debt Instrument [Line Items]
Long-term debt, gross	0	$ 1,501
Weighted-average interest rate		2.01%
Capital Holdings [Member]
Debt Instrument [Line Items]
Fair value hedge adjustment	(1)	$ 1
Unamortized debt issuance costs and discount	(88)	(94)
Total long-term debt	13,013	11,256
Less current maturities of long-term debt	2,019	645
Long-term debt, excluding current maturities	10,994	10,611
Capital Holdings [Member] | Other long-term debt - variable [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 50	$ 52
Weighted-average interest rate	3.53%	2.58%
Capital Holdings [Member] | Other long-term debt - fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 818	$ 920
Weighted-average interest rate	2.57%	2.46%
Capital Holdings [Member] | Debentures - fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 4,300	$ 4,100
Weighted-average interest rate	3.21%	3.00%
Capital Holdings [Member] | Debentures variable [Domain]
Debt Instrument [Line Items]
Long-term debt, gross	$ 2,341	$ 0
Weighted-average interest rate	3.11%
Capital Holdings [Member] | Debentures, related to NEE's equity units - fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,500	$ 2,200
Weighted-average interest rate	1.65%	1.88%
Capital Holdings [Member] | Junior subordinated debentures - primarily fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 3,456	$ 3,456
Weighted-average interest rate	4.99%	4.79%
Capital Holdings [Member] | Japanese yen denominated senior notes - fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 91	$ 89
Weighted-average interest rate	5.13%	5.13%
Capital Holdings [Member] | Japanese yen denominated term loans - variable [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 546	$ 532
Weighted-average interest rate	2.76%	2.76%
NEER [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs and premium - net	$ (93)	$ (181)
Total long-term debt	4,702	10,176
Less current maturities of long-term debt	602	564
Long-term debt, excluding current maturities	4,100	9,612
Debt related to events of default associated with the bankruptcy filing of a counterparty to several PPAs	365
NEER [Member] | Senior secured limited-recourse bonds and notes - fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 325	$ 2,114
Weighted-average interest rate	4.25%	5.74%
NEER [Member] | Senior secured limited-recourse term loans - primarily variable [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 3,869	$ 5,165
Weighted-average interest rate	4.39%	3.32%
NEER [Member] | Senior Unsecured Notes - Fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	$ 1,100
Weighted-average interest rate		4.38%
NEER [Member] | Senior Unsecured NEP Convertible Notes - Fixed [Member]
Debt Instrument [Line Items]
Long-term debt, gross	0	$ 300
Weighted-average interest rate		1.50%
NEER [Member] | Other long-term debt - primarily variable [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 601	$ 1,678
Weighted-average interest rate	2.57%	3.28%
Wholly-Owned Subsidiary of NEER [Member]
Debt Instrument [Line Items]
Debt collateralized by third party note receivable		$ 483
NEP [Member]
Debt Instrument [Line Items]
Debt conversion, converted instrument, rate	0.018917

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

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