Earnings Per Share - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Basic net income per share:
Net income (loss) attributable to InfraREIT, Inc.	$ 6,315	$ (26,873)
Weighted average common shares outstanding	43,570	41,204
Basic net income (loss) per share	$ 0.14	$ (0.65)
Diluted net income per share:
Net income (loss) attributable to InfraREIT, Inc.	$ 6,315	$ (26,873)
Weighted average common shares outstanding	43,570	41,204
Weighted average dilutive shares outstanding	43,570	41,204
Diluted net income (loss) per share	$ 0.14	$ (0.65)
Due to the anti-dilutive effect, the computation of diluted earnings per share does not reflect the following adjustments:
Net income (loss) attributable to noncontrolling interest	$ 2,462	$ (9,000)
Redemption of operating partnership units	17,057	13,801