Capitalization - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net loss attributable to NEP – basic	$ (222)	$ (22)
Adjustments for convertible notes and preferred units(a)	0	0
Net loss attributable to NEP used to compute diluted loss per unit	$ (222)	$ (22)
Denominator:
Weighted average number of common units outstanding - basic (in shares)	65.5	56.1
Convertible notes and preferred units (in shares)	0.0	0.0
Weighted-average number of common units outstanding – assuming dilution (in shares)	65.5	56.1
Loss per unit attributable to NEP:
Basic (in shares)	$ (3.39)	$ (0.38)
Assuming dilution (in shares)	$ (3.39)	$ (0.38)
Antidilutive shares (in shares)	10.3	19.7