CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Total InfraREIT, Inc. Equity	Noncontrolling Interest
Balance at Dec. 31, 2016	$ 943,911	$ 438	$ 705,845	$ (18,243)	$ 688,040	$ 255,871
Balance, shares at Dec. 31, 2016		43,772,283
Dividends and distributions	(15,169)			(10,944)	(10,944)	(4,225)
Redemption of operating partnership units for common stock			55		55	(55)
Redemption of operating partnership units for common stock, shares		3,100
Net income	11,017			7,949	7,949	3,068
Equity based compensation	140					140
Balance at Mar. 31, 2017	939,899	$ 438	705,900	(21,238)	685,100	254,799
Balance, shares at Mar. 31, 2017		43,775,383
Balance at Dec. 31, 2016	$ 943,911	$ 438	705,845	(18,243)	688,040	255,871
Balance, shares at Dec. 31, 2016		43,772,283
Redemption of operating partnership units for common stock, shares	23,349
Net income	$ 42,384
Balance at Sep. 30, 2017	941,216	$ 438	706,337	(20,494)	686,281	254,935
Balance, shares at Sep. 30, 2017		43,795,632
Balance at Mar. 31, 2017	939,899	$ 438	705,900	(21,238)	685,100	254,799
Balance, shares at Mar. 31, 2017		43,775,383
Dividends and distributions	(15,169)			(10,944)	(10,944)	(4,225)
Redemption of operating partnership units for common stock			55		55	(55)
Redemption of operating partnership units for common stock, shares		3,107
Net income	10,129			7,308	7,308	2,821
Equity based compensation	145					145
Balance at Jun. 30, 2017	935,004	$ 438	705,955	(24,874)	681,519	253,485
Balance, shares at Jun. 30, 2017		43,778,490
Dividends and distributions	(15,169)			(10,950)	(10,950)	(4,219)
Redemption of operating partnership units for common stock			382		382	(382)
Redemption of operating partnership units for common stock, shares		17,142
Net income	21,238			15,330	15,330	5,908
Equity based compensation	143					143
Balance at Sep. 30, 2017	941,216	$ 438	706,337	(20,494)	686,281	254,935
Balance, shares at Sep. 30, 2017		43,795,632
Balance at Dec. 31, 2017	900,858	$ 438	706,357	(49,728)	657,067	243,791
Balance, shares at Dec. 31, 2017		43,796,915
Dividends and distributions	(15,176)			(10,990)	(10,990)	(4,186)
Redemption of operating partnership units for common stock		$ 2	3,104		3,106	(3,106)
Redemption of operating partnership units for common stock, shares		163,969
Net income	17,764			12,864	12,864	4,900
Equity based compensation	140					140
Balance at Mar. 31, 2018	903,586	$ 440	709,461	(47,854)	662,047	241,539
Balance, shares at Mar. 31, 2018		43,960,884
Balance at Dec. 31, 2017	$ 900,858	$ 438	706,357	(49,728)	657,067	243,791
Balance, shares at Dec. 31, 2017		43,796,915
Redemption of operating partnership units for common stock, shares	165,252
Net income	$ 61,406
Balance at Sep. 30, 2018	917,176	$ 440	709,488	(38,229)	671,699	245,477
Balance, shares at Sep. 30, 2018		43,962,167
Balance at Mar. 31, 2018	903,586	$ 440	709,461	(47,854)	662,047	241,539
Balance, shares at Mar. 31, 2018		43,960,884
Dividends and distributions	(15,176)			(10,990)	(10,990)	(4,186)
Redemption of operating partnership units for common stock			27		27	(27)
Redemption of operating partnership units for common stock, shares		1,283
Net income	23,936			17,334	17,334	6,602
Equity based compensation	180					180
Balance at Jun. 30, 2018	912,526	$ 440	709,488	(41,510)	668,418	244,108
Balance, shares at Jun. 30, 2018		43,962,167
Dividends and distributions	(15,176)			(10,990)	(10,990)	(4,186)
Net income	19,706			14,271	14,271	5,435
Equity based compensation	120					120
Balance at Sep. 30, 2018	$ 917,176	$ 440	$ 709,488	$ (38,229)	$ 671,699	$ 245,477
Balance, shares at Sep. 30, 2018		43,962,167