CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net income	$ 69,301,000	$ 19,931,000	$ 29,780,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	46,704,000	40,211,000	35,080,000
Amortization of deferred financing costs	4,014,000	3,241,000	4,383,000
Allowance for funds used during construction — other funds	(3,728,000)	(3,048,000)	(1,106,000)
Change in fair value of contingent consideration			18,357,000
Reorganization structuring fee		44,897,000
Realized gain on sale of marketable securities		(66,000)
Equity based compensation	978,000	678,000	120,000
Changes in assets and liabilities:
Due from affiliates	(1,382,000)	(3,350,000)	(7,275,000)
Inventory	(545,000)	662,000	(816,000)
Prepaids and other current assets	(166,000)	(6,000)	(3,370,000)
Accounts payable and accrued liabilities	7,958,000	2,644,000	7,347,000
Net cash provided by operating activities	123,134,000	105,794,000	82,500,000
Cash flows from investing activities
Additions to electric plant	(231,312,000)	(239,157,000)	(210,791,000)
Proceeds from sale of assets		41,211,000
Sale of marketable securities		1,065,000
Cash paid to InfraREIT, L.L.C. investors in the merger, net of cash assumed		(172,400,000)
Net cash used in investing activities	(231,312,000)	(369,281,000)	(210,791,000)
Cash flows from financing activities
Net proceeds from issuance of common stock upon initial public offering		493,722,000
Proceeds from short-term borrowings	139,500,000	87,000,000	354,000,000
Repayments of short-term borrowings	(56,000,000)	(253,000,000)	(210,000,000)
Proceeds from borrowings of long-term debt	100,000,000	400,000,000	11,000,000
Repayments of long-term debt	(7,423,000)	(404,867,000)	(13,934,000)
Net change in restricted cash			(1,000)
Deferred financing costs	(649,000)	(3,914,000)	(4,908,000)
Dividends and distributions paid	(59,109,000)	(61,595,000)	0
Net cash provided by financing activities	116,319,000	257,346,000	136,157,000
Net increase (decrease) in cash and cash equivalents	8,141,000	(6,141,000)	7,866,000
Cash and cash equivalents at beginning of year	9,471,000	15,612,000	7,746,000
Cash and cash equivalents at end of year	$ 17,612,000	$ 9,471,000	$ 15,612,000