Fair Value Measurements (Nonrecurring Fair Value Measurements) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on assets previously held for sale	$ 21	$ (67)
Impairment of Long-Lived Assets Held-for-use	0	300
Impairment Of Long Lived Assets Held For Use After Tax		342
NextEra Energy Resources [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Planned capacity of Spain Solar projects - in megawatts		99.8
Carrying value of property, plant, and equipment prior to impairment charge		800
Property, Plant, and Equipment, Fair Value Disclosure		500
Impairment of Long-Lived Assets Held-for-use		300
Impairment Of Long Lived Assets Held For Use After Tax		342
Maine fossil [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on assets previously held for sale	21	(67)
After-tax gain (loss) on assets previously held for sale	$ 12	$ (43)
Capacity associated with assets previously held for sale (in megawatts)	796