NEP Deconsolidation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Investment [Line Items]
Investment in equity method investees	$ 6,774	$ 2,321
Deconsolidation, revaluation of retained investment, gain (loss), amount, before tax	3,900
Deconsolidation, revaluation of retained investment, gain (loss), amount, after tax	3,000
Plant, property, and equipment, decrease from deconsolidation	7,800
Long-term debt, decrease from deconsolidation	4,800
Noncontrolling interest, decrease from deconsolidation	2,700
Fee income	24
Due from related parties, current	40
Due from related parties, noncurrent	22
Guarantor obligations, current carrying value	690
Debt instrument, fair value disclosure	32
NextEra Energy Partners [Member]
Investment [Line Items]
Investment in equity method investees	$ 4,400
Equity method investment, ownership percentage	2.60%
Equity method investment, difference between carrying amount and underlying equity	$ 3,500
NEP OpCo [Member]
Investment [Line Items]
Limited liability company or limited partnership, members or limited partners, ownership interest	65.10%
NextEra Energy Partners [Member]
Investment [Line Items]
Due to related parties	$ 89