Equity (Narrative) (Details) - USD ($)	1 Months Ended	9 Months Ended
	Nov. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Forward sale agreement, number of shares	12,000,000
Forward sale price (in dollars per share)	$ 124.00
Common Stock [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares)		2,000,000	5,000,000
Forward Counterparty [Member] | Common Stock [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares)		1,711,345
Series A Preferred Units [Member] | NextEra Energy Partners, LP [Member]
Class of Stock [Line Items]
Preferred unit purchase agreement, amount to be issued and sold		$ 550,000,000