InfraREIT (HIFR) 10-Q 2 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 29, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	HIFR
Entity Registrant Name	InfraREIT, Inc.
Entity Central Index Key	0001506401
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		44,005,370

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 3,487	$ 1,808
Restricted cash	1,693	1,689
Due from affiliates	33,126	38,174
Inventory	6,862	6,903
Prepaids and other current assets	2,648	1,077
Total current assets	47,816	49,651
Electric Plant, net	1,814,584	1,811,317
Goodwill	138,384	138,384
Other Assets	31,671	31,678
Total Assets	2,032,455	2,031,030
Current Liabilities
Accounts payable and accrued liabilities	20,881	19,657
Short-term borrowings	106,500	112,500
Current portion of long-term debt	8,919	8,792
Dividends and distributions payable	15,182	15,176
Accrued taxes	1,307	1,052
Total current liabilities	152,789	157,177
Long-Term Debt, Less Deferred Financing Costs	830,185	832,455
Regulatory Liabilities	119,362	115,532
Long-Term Operating Lease Liabilities	345
Total liabilities	1,102,681	1,105,164
Commitments and Contingencies
Equity
Common stock, $0.01 par value; 450,000,000 shares authorized; 44,005,370 and 43,974,998 issued and outstanding as of March 31, 2019 and December 31, 2018, respectively	440	440
Additional paid-in capital	708,519	708,283
Accumulated deficit	(29,278)	(32,022)
Total InfraREIT, Inc. equity	679,681	676,701
Noncontrolling interest	250,093	249,165
Total equity	929,774	925,866
Total Liabilities and Equity	$ 2,032,455	$ 2,031,030

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Common stock, par or stated value per share	$ 0.01	$ 0.01
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	44,005,370	43,974,998
Common stock, shares, outstanding	44,005,370	43,974,998

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Lease revenue	$ 48,574	$ 45,656
Operating costs and expenses
General and administrative expense	7,087	6,088
Depreciation	12,204	11,577
Total operating costs and expenses	19,291	17,665
Income from operations	29,283	27,991
Other (expense) income
Interest expense, net	(10,060)	(10,674)
Other income, net	1	733
Total other expense	(10,059)	(9,941)
Income before income taxes	19,224	18,050
Income tax expense	255	286
Net income	18,969	17,764
Less: Net income attributable to noncontrolling interest	5,224	4,900
Net income attributable to InfraREIT, Inc.	$ 13,745	$ 12,864
Net income attributable to InfraREIT, Inc. common stockholders per share:
Basic	$ 0.31	$ 0.29
Diluted	0.31	0.29
Cash dividends declared per common share	$ 0.25	$ 0.25

CONSOLIDATED STATEMENTS OF STOC

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, 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	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, 2018	925,866	$ 440	708,283	(32,022)	676,701	249,165
Balance, shares at Dec. 31, 2018		43,974,998
Dividends and distributions	$ (15,181)			(11,001)	(11,001)	(4,180)
Redemption of operating partnership units for common stock			116		116	(116)
Redemption of operating partnership units for common stock, shares	7,698	7,698
Common stock issued, shares		22,674
Net income	$ 18,969			13,745	13,745	5,224
Equity based compensation	120		120		120
Balance at Mar. 31, 2019	$ 929,774	$ 440	$ 708,519	$ (29,278)	$ 679,681	$ 250,093
Balance, shares at Mar. 31, 2019		44,005,370

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities
Net income	$ 18,969	$ 17,764
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	12,204	11,577
Amortization of deferred financing costs	361	1,071
Allowance for funds used during construction - other funds		(730)
Equity based compensation	120	140
Changes in assets and liabilities:
Due from affiliates	5,048	2,567
Inventory	41	(132)
Prepaids and other current assets	(1,553)	(573)
Accounts payable and accrued liabilities	1,217	3,153
Net cash provided by operating activities	36,407	34,837
Cash flows from investing activities
Additions to electric plant	(11,396)	(15,011)
Proceeds from asset exchange transaction		1,632
Net cash used in investing activities	(11,396)	(13,379)
Cash flows from financing activities
Proceeds from short-term borrowings	22,000	12,000
Repayments of short-term borrowings	(28,000)	(17,500)
Repayments of long-term debt	(2,152)	(2,032)
Dividends and distributions paid	(15,176)	(15,169)
Net cash used in financing activities	(23,328)	(22,701)
Net increase (decrease) in cash, cash equivalents and restricted cash	1,683	(1,243)
Cash, cash equivalents and restricted cash at beginning of period	3,497	4,550
Cash, cash equivalents and restricted cash at end of period	$ 5,180	$ 3,307

Description of Business and Pre

Description of Business and Presentation of Financial Statements	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Presentation of Financial Statements	1. Description of Business and Presentation of Financial Statements Basis of Presentation InfraREIT, Inc. is a Maryland corporation, which may be referred to in these financial statements as the “Company,” “InfraREIT,” “we,” “us” and “our.” These unaudited interim consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three months ended March 31, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. For further information, refer to the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2018 filed with the U.S. Securities and Exchange Commission (SEC) on February 27, 2019 (2018 Form 10-K). We hold 72.5% of the outstanding partnership units (OP Units) in InfraREIT Partners, LP (Operating Partnership or InfraREIT LP) as of March 31, 2019 and are its general partner. We include the accounts of the Operating Partnership and its subsidiaries in our consolidated financial statements. Affiliates and current or former employees of Hunt Consolidated, Inc. (Hunt) and members of our board of directors hold the other 27.5% of the outstanding OP Units as of March 31, 2019. Use of Estimates The preparation of our consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Recent Accounting Guidance Recently Adopted Accounting Guidance In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842 Leases (Topic 842), Narrow-Scope Improvements for Lessors, Leases (Topic 842): Targeted Improvements, Leases Recent Accounting Guidance Not Yet Adopted In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement

Pending Corporate Transactions

Pending Corporate Transactions	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Pending Corporate Transactions	2 . Pending Corporate Transactions Sale and Asset Exchange On October 18, 2018, InfraREIT and InfraREIT LP entered into a definitive agreement to be acquired by Oncor Electric Delivery Company LLC (Oncor) for $21.00 per share or OP Unit, as applicable, in cash, valued at approximately $1.275 billion, plus the assumption of InfraREIT’s net debt of approximately $940 million as of March 31, 2019. As a condition to Oncor’s acquisition of InfraREIT, Sharyland Distribution & Transmission, L.L.C. (SDTS) and Oncor also signed a definitive agreement with Sharyland Utilities, L.P. (Sharyland) to exchange, immediately prior to Oncor’s acquisition, SDTS’s South Texas assets for Sharyland’s Golden Spread Electric Cooperative interconnection located in the Texas Panhandle, along with certain development projects in the Texas Panhandle and South Plains regions, including the Lubbock Power & Light interconnection. The difference between the net book value of the exchanged assets will be paid in cash at closing. SDTS and Sharyland have agreed to terminate their existing leases in connection with the asset exchange. The asset exchange with Sharyland and merger with Oncor are mutually dependent on one another, and neither will become effective without the closing of the other. Arrangements with Hunt Under the management agreement with Hunt Utility Services, LLC (Hunt Manager), which will be terminated upon the closing of the sale and asset exchange transaction described above, Hunt Manager is entitled to the payment of a termination fee upon the termination or non-renewal of the management agreement. The termination of the management agreement automatically triggers the termination of the development agreement between InfraREIT and Hunt. InfraREIT has agreed to pay Hunt approximately $40.5 million at the closing of the transactions to terminate the management agreement, development agreement, leases with Sharyland, and all other existing agreements between InfraREIT or its subsidiaries and Hunt, Sharyland or their affiliates. This amount is consistent with the termination fee, as calculated at the time the Company entered into the omnibus termination agreement, contractually required under the management agreement. Closing Conditions and Status The closing of the transactions is dependent upon and subject to several closing conditions, including: • Public Utility Commission of Texas (PUCT) approval of the transactions, including: o exchange of assets with Sharyland; o acquisition of InfraREIT by Oncor; and o Sempra Energy’s 50% ownership of Sharyland Holdings LP; • other necessary regulatory approvals, including approval by the Federal Energy Regulatory Commission (FERC), the expiration or termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (HSR Act) and clearance by the Committee on Foreign Investment in the United States (CFIUS); • stockholder approval; • certain lender consents; and • other customary closing conditions. Early termination of the 30-day waiting period required by the HSR Act was received in December 2018. In December 2018, the Operating Partnership’s wholly-owned subsidiary, Transmission and Distribution Company, L.L.C. (TDC) and SDTS entered into amendments that, effective as of the closing, will satisfy the closing condition with respect to the lender consents. Additionally, a special meeting of InfraREIT’s stockholders was held on February 7, 2019, at which time the stockholders voted to approve the transaction. Furthermore, in March 2019, CFIUS clearance was received for the transactions and FERC issued an order approving the transactions. SDTS, Sharyland, Oncor and Sempra Energy filed a Sale-Transfer-Merger (STM) application with the PUCT on November 30, 2018. In April 2019, the parties to the STM proceeding filed a Stipulation (Settlement) with the PUCT, which is subject to review and approval by the PUCT. A hearing on the merits was held on April 10, 2019. The 180-day deadline for the STM is May 29, 2019, although the PUCT is permitted to extend that deadline for an additional 60 days if necessary. During the three months ended March 31, 2019, we incurred expenses of $1.7 million for the sale of InfraREIT and related transactions which are included in general and administrative expense on our Consolidated Statements of Operations. We did not have these expenses during the three months ended March 31, 2018 as the definitive agreements with respect to the transactions were not executed until October 2018. We continue to expect the transactions to close by mid-2019, subject to obtaining the PUCT approval and satisfaction of other customary closing conditions. See Note 20, Subsequent Events

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash	3 Months Ended
	Mar. 31, 2019
Cash And Cash Equivalents [Abstract]
Cash, Cash Equivalents and Restricted Cash	3 . Cash, Cash Equivalents and Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash within the Consolidated Balance Sheets that sum to the total of the same such amounts shown on the Consolidated Statements of Cash Flows: March 31, (In thousands) 2019 2018 Cash and cash equivalents $ 3,487 $ 1,624 Restricted cash 1,693 1,683 Total cash, cash equivalents and restricted cash shown on the Statement of Cash Flows $ 5,180 $ 3,307 Amounts included in restricted cash represent the principal and interest payable for two consecutive periods associated with the $25.0 million senior secured notes of TDC, as described in Note 9, Long-Term Debt

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	4 . Related Party Transactions We lease, through SDTS, all our regulated assets to Sharyland through several lease agreements. Under the leases, we have agreed to fund capital expenditures for footprint projects. Our leases define “footprint projects” to be transmission or, if applicable, distribution projects that (1) are primarily situated within our current or previous distribution service territory, as applicable, (2) physically hang from our existing transmission assets, such as the addition of another circuit to our existing transmission lines, or that are physically located within one of our substations or (3) connect or are otherwise added to transmission lines or other properties that comprise a part of the transmission assets acquired from Oncor in 2017 when SDTS exchanged all of its retail distribution assets for a group of Oncor’s transmission assets located near Wichita Falls, Abilene and Brownwood, Texas (2017 Asset Exchange Transaction). Footprint Projects do not include the addition of a new substation on our existing transmission lines or generation interconnections to our existing transmission lines, unless the addition or interconnection occurred within our current or prior distribution service territories. We earned lease revenue from Sharyland under these agreements of $48.6 million and $45.7 million during the three months ended March 31, 2019 and 2018, respectively. In connection with our leases with Sharyland, we had a deferred rent liability of $9.8 million and $11.1 million as of March 31, 2019 and December 31, 2018, respectively, which is included in accounts payable and accrued liabilities on the Consolidated Balance Sheets. In addition to rent payments that Sharyland makes to us, we and Sharyland also make payments to each other under the leases that primarily consist of payments to reimburse Sharyland for the costs of gross plant and equipment added to our regulated assets. For the three months ended March 31, 2019 and 2018, the net amount of payments we made to Sharyland was $9.9 million and $15.0 million, respectively. As of March 31, 2019 and December 31, 2018, accounts payable and accrued liabilities on the Consolidated Balance Sheets included $3.2 million and $2.9 million, respectively, related to amounts owed to Sharyland for construction costs incurred and property taxes paid on our behalf. As of March 31, 2019 and December 31, 2018, amounts due from affiliates on the Consolidated Balance Sheets included $33.1 million and $38.2 million, respectively, related to amounts owed by Sharyland primarily associated with our leases. The management fee paid to Hunt Manager for the three months ended March 31, 2019 and 2018 was $3.4 million and $3.5 million, respectively. There were no prepaid or accrued amounts associated with the management fees on the Consolidated Balance Sheets as of March 31, 2019 and December 31, 2018. Additionally, during the three months ended March 31, 2019 and 2018, we paid Hunt Manager less than $0.1 million for reimbursement of annual software license and maintenance fees and other expenses in accordance with our management agreement. The management agreement with Hunt Manager provides for an annual base fee, or management fee. The base fee for each 12-month period beginning each April 1 will equal 1.50% of our total equity as of December 31 of the immediately preceding year, subject to a $30.0 million cap. We must notify Hunt Manager no later than September 30, 2019 if we intend not to renew the management agreement at the end of its current term, which expires December 31, 2019. Otherwise, the management agreement will automatically renew for successive five-year terms unless a majority of our independent directors decides to terminate the agreement. The base fees through December 31, 2019 are as follows: (In millions) Base Fee April 1, 2017 - March 31, 2018 $ 14.2 April 1, 2018 - March 31, 2019 13.5 April 1, 2019 - December 31, 2019 10.4 If the management agreement is renewed under its current terms, we would owe $3.5 million for the first quarter of 2020, and the management fee owed for the subsequent 12-month period would be calculated as described above. If, instead, the management agreement is terminated, we would owe Hunt Manager a termination fee equal to three times the sum of the management fee paid during the four quarters prior to when the termination notice was given with payment due December 31, 2019. Assuming a termination notice of September 30, 2019, the termination fee would be approximately $41.1 million. For information related to the pending sale of InfraREIT and asset exchange with Sharyland, including the proposed termination of the leases and management agreement, see Note 2, Pending Corporate Transactions In July 2017, SDTS and Sharyland entered into a letter agreement (Side Letter) in which they agreed to certain terms and conditions to address the actual or potential conflicts of interest arising between SDTS and Sharyland in connection with the 2017 Asset Exchange Transaction. Specifically, the Side Letter includes, among other things, certain representations and warranties from Sharyland that correspond to representations and warranties of SDTS under the 2017 Asset Exchange Agreement relating to certain matters for which SDTS relies, in whole or in part, upon Sharyland under the leases and as operator of the assets and an allocation of expenses incurred in connection with the transactions. As a condition to Oncor’s acquisition of InfraREIT, in October 2018 SDTS entered into a definitive agreement to exchange certain assets with Sharyland. See Note 2, Pending Corporate Transactions In connection with the sale of InfraREIT and related transactions, in October 2018 we entered into an omnibus termination agreement pursuant to which the management agreement, development agreement, leases and all other existing agreements between us and Hunt, Sharyland or their affiliates will be terminated upon the closing. Under the omnibus termination agreement, we have agreed to pay Hunt approximately $40.5 million upon the closing of the sale. This amount is consistent with the termination fee, as calculated at the time we entered into the omnibus termination agreement, contractually required under the management agreement. For additional information, see Note 2, Pending Corporate Transactions

Electric Plant and Depreciation

Electric Plant and Depreciation	3 Months Ended
	Mar. 31, 2019
Public Utilities Property Plant And Equipment [Abstract]
Electric Plant and Depreciation	5 . Electric Plant and Depreciation The major classes of electric plant are as follows: (In thousands) March 31, 2019 December 31, 2018 Electric plant: Transmission plant $ 1,794,442 $ 1,794,438 Distribution plant 151,698 151,698 General plant 3,210 3,023 Total plant in service 1,949,350 1,949,159 Construction work in progress 77,568 66,121 Total electric plant 2,026,918 2,015,280 Accumulated depreciation (212,334 ) (203,963 ) Electric plant, net $ 1,814,584 $ 1,811,317 General plant consists primarily of a warehouse, buildings and associated assets. Construction work in progress (CWIP) reflects the regulated asset projects in various stages of construction prior to being placed in service. The capitalized amounts of CWIP consist primarily of route development expenditures, labor and materials expenditures, right of way acquisitions, engineering services and legal fees. Electric plant, net includes plant acquisition adjustments of $28.2 million and $28.5 million as of March 31, 2019 and December 31, 2018, respectively.

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	6 . Goodwill Goodwill represents the excess of costs of an acquired business over the fair value of the assets acquired, less liabilities assumed. We conduct an impairment test of goodwill at least annually. As of March 31, 2019 and December 31, 2018, $138.4 million was recorded as goodwill on the Consolidated Balance Sheets.

Other Assets

Other Assets	3 Months Ended
	Mar. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Other Assets	7 . Other Assets Other assets are as follows: March 31, 2019 December 31, 2018 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Deferred financing costs on undrawn revolver $ 1,025 $ (811 ) $ 214 $ 1,025 $ (779 ) $ 246 Other regulatory assets: Deferred financing costs 10,610 (5,810 ) 4,800 10,610 (5,490 ) 5,120 Deferred costs recoverable in future years 23,793 — 23,793 23,793 — 23,793 Other regulatory assets 34,403 (5,810 ) 28,593 34,403 (5,490 ) 28,913 Operating lease right-of-use asset 345 — 345 — — — Investments 2,519 — 2,519 2,519 — 2,519 Other assets $ 38,292 $ (6,621 ) $ 31,671 $ 37,947 $ (6,269 ) $ 31,678 Deferred financing costs on undrawn revolver consist of costs incurred in connection with the establishment of the InfraREIT LP revolving credit facility. See Note 8, Borrowings Under Credit Facilities Other regulatory assets consist of deferred financing costs within our regulated subsidiary, SDTS. The deferred financing costs primarily consist of debt issuance costs incurred in connection with the construction of SDTS’s regulated assets or the refinancing of related debt. These assets are classified as regulatory assets and amortized over the length of the related loan. These costs are recovered through rates established in rate cases. Deferred costs recoverable in future years of $23.8 million at March 31, 2019 and December 31, 2018 represent operating costs incurred from the inception of Sharyland through 2007. We have determined that these costs are probable of recovery through future rates based on orders of the PUCT in Sharyland’s prior rate cases and regulatory precedent. Operating lease right-of-use asset represents the asset associated with two land leases in which we are the lessee. For additional information see Note 16, Leases In connection with the acquisition of Cap Rock Holding Corporation, we received a participation in the National Rural Utilities Cooperative Finance Corporation. We account for this investment under the cost method of accounting. We believe that the investment is not impaired as of March 31, 2019 and December 31, 2018.

Borrowings Under Credit Facilit

Borrowings Under Credit Facilities	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Borrowings Under Credit Facilities	8 . Borrowings Under Credit Facilities InfraREIT LP Revolving Credit Facility In 2014, InfraREIT LP entered into a $75.0 million revolving credit facility, led by Bank of America, N.A., as administrative agent, with up to $15.0 million available for issuance of letters of credit and a maturity date of December 10, 2019. In December 2018, InfraREIT LP entered into an amendment to its revolving credit facility that extended the maturity date with respect to $67.0 million of the available revolving credit facility to December 10, 2020. The remaining $8.0 million of the available revolving credit facility will continue to mature on December 10, 2019. The revolving credit facility is secured by certain assets of InfraREIT LP, including accounts and other personal property, and is guaranteed by us and TDC, with the TDC guarantee secured by the assets of, and InfraREIT LP’s equity interests in, TDC on materially the same basis as TDC’s senior secured notes described below in Note 9, Long-Term Debt Borrowings and other extensions of credit under the revolving credit facility bear interest, at InfraREIT LP’s election, at a rate equal to (1) the one, two, three or six month London Interbank Offered Rate (LIBOR) plus 2.5%, or (2) a base rate (equal to the highest of (a) the Federal Funds Rate plus ½ of 1%, (b) the administrative agent’s prime rate and (c) LIBOR plus 1%) plus 1.5%. Letters of credit are subject to a letter of credit fee equal to the daily amount available to be drawn times 2.5%. InfraREIT LP is also required to pay a commitment fee and other customary fees under the revolving credit facility. InfraREIT LP may prepay amounts outstanding under the revolving credit facility in whole or in part without premium or penalty. As of March 31, 2019 and December 31, 2018, there were no borrowings or letters of credit outstanding, and there was $75.0 million of borrowing capacity available under the revolving credit facility. As of March 31, 2019 and December 31, 2018, InfraREIT LP was in compliance with all debt covenants under the credit agreement. SDTS Revolving Credit Facility In 2014, SDTS entered into a third amended and restated credit agreement led by Royal Bank of Canada, as administrative agent. In December 2018, SDTS entered into an amendment to its revolving credit agreement that extended the maturity date from December 10, 2019 to December 10, 2020. The credit agreement contains a revolving credit facility with a borrowing capacity up to $250.0 million with up to $25.0 million of the revolving credit facility available for issuance of letters of credit and up to $5.0 million of the revolving credit facility available for swingline loans. The revolving credit facility is secured by certain of SDTS’s regulated assets, the leases, certain accounts and TDC’s equity interests in SDTS on the same basis as SDTS’s various senior secured note obligations described below in Note 9, Long-Term Debt The interest rate for the revolving credit facility is based, at SDTS’s option, at a rate equal to either (1) a base rate, determined as the greatest of (a) the administrative agent’s prime rate, (b) the federal funds effective rate plus ½ of 1% and (c) LIBOR plus 1.00% per annum, plus a margin of either 0.75% or 1.00% per annum, depending on the total debt to capitalization ratio of SDTS on a consolidated basis or (2) LIBOR plus a margin of either 1.75% or 2.00% per annum, depending on the total debt to capitalization ratio of SDTS on a consolidated basis. SDTS is also required to pay a commitment fee and other customary fees under its revolving credit facility. SDTS is entitled to prepay amounts outstanding under the revolving credit facility with no prepayment penalty. As of March 31, 2019, SDTS had $106.5 million of borrowings outstanding at a weighted average interest rate of 4.49%, no letters of credit outstanding and $143.5 million of borrowing capacity available under this revolving credit facility. As of December 31, 2018, SDTS had $112.5 million of borrowings outstanding at a weighted average interest rate of 4.59% with no letters of credit outstanding and $137.5 million of borrowing capacity available under this revolving credit facility. As of March 31, 2019 and December 31, 2018, SDTS was in compliance with all debt covenants under the credit agreement. The credit agreements require InfraREIT LP and SDTS to comply with customary covenants for facilities of this type, including: debt to capitalization ratios; debt service coverage ratios; limitations on additional debt, liens, investments, mergers, acquisitions, dispositions or entry into any line of business other than the business of the transmission and distribution of electric power and the provision of ancillary services; and certain restrictions on the payment of dividends. The debt to capitalization ratio on the SDTS credit facility is calculated on a combined basis with Sharyland. The credit agreements also contain restrictions on the amount of Sharyland’s indebtedness and other restrictions on, and covenants applicable to, Sharyland. The revolving credit facilities of InfraREIT LP and SDTS are subject to customary events of default. If an event of default occurs under either facility and is continuing, the lenders may accelerate amounts due under such revolving credit facility.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2019
Debt Instruments [Abstract]
Long-Term Debt	9 . Long-Term Debt Long-term debt consisted of the following: March 31, 2019 December 31, 2018 (Dollar amounts in thousands) Maturity Date Amount Outstanding Interest Rate Amount Outstanding Interest Rate TDC Senior secured notes - $25.0 million December 30, 2020 $ 14,687 8.50% $ 15,000 8.50% SDTS Senior secured term loan - $200.0 million June 5, 2020 200,000 3.74% 200,000 3.73% Senior secured notes - $400.0 million December 3, 2025 400,000 3.86% 400,000 3.86% Senior secured notes - $100.0 million January 14, 2026 100,000 3.86% 100,000 3.86% Senior secured notes - $53.5 million December 30, 2029 37,762 7.25% 38,338 7.25% Senior secured notes - $110.0 million September 30, 2030 86,712 6.47% 87,973 6.47% Total SDTS debt 824,474 826,311 Total long-term debt 839,161 841,311 Less unamortized deferred financing costs (57 ) (64 ) Total long-term debt, less deferred financing costs 839,104 841,247 Less current portion of long-term debt (8,919 ) (8,792 ) Debt classified as long-term debt, less deferred financing costs $ 830,185 $ 832,455 In 2010, TDC issued $25.0 million aggregate principal amount of 8.50% per annum senior secured notes to The Prudential Insurance Company of America and affiliates (TDC Notes). Principal and interest on the TDC Notes are payable quarterly, and the TDC Notes are secured by the assets of, and InfraREIT LP’s equity interest in, TDC on materially the same basis as with lenders under InfraREIT LP’s revolving credit facility described above in Note 8, Borrowings Under Credit Facilities In 2017, SDTS entered into a $200.0 million senior secured term loan credit facility (2017 Term Loan) with Canadian Imperial Bank of Commerce, New York Branch (CIBC) and Mizuho Bank, Ltd., as lenders, and CIBC as administrative agent. The interest rate for the 2017 Term Loan is based, at SDTS’s option, at a rate equal to either (1) a base rate, determined as the greatest of (a) the administrative agent’s prime rate, (b) the federal funds effective rate plus 0.5% and (c) LIBOR plus 1.00% per annum, plus a margin of 0.25% per annum or (2) LIBOR plus a margin of 1.25% per annum. The LIBOR interest period may be one, two, three or six months, but interest is payable no less frequently than quarterly. In 2015, SDTS issued $400.0 million series A senior secured notes (Series A Notes), and in 2016 issued an additional $100.0 million series B senior secured notes (Series B Notes). These senior secured notes are due at maturity and bear interest at a rate of 3.86% per annum, payable semi-annually. The outstanding accrued interest payable on the Series A Notes is due each June and December while the accrued interest payable on the Series B Notes is due each January and July. In 2009, SDTS issued $53.5 million aggregate principal amount of 7.25% per annum senior secured notes to The Prudential Insurance Company of America and affiliates (2009 Notes). Principal and interest on the 2009 Notes are payable quarterly. In 2010, SDTS issued $110.0 million aggregate principal amount of 6.47% per annum senior secured notes to The Prudential Insurance Company of America (2010 Notes). Principal and interest on the 2010 Notes are payable quarterly. SDTS and TDC are entitled to prepay amounts outstanding under their senior secured notes, subject to a prepayment penalty equal to the excess of the discounted value of the remaining scheduled payments with respect to such notes over the amount of the prepaid notes. SDTS is entitled to prepay amounts outstanding under the 2017 Term Loan with no prepayment penalty. The 2017 Term Loan is also subject to required prepayments upon the occurrence of certain events. The agreements governing the senior secured notes and 2017 Term Loan contain customary covenants, such as debt to capitalization ratios, debt service coverage ratios, limitations on liens, dispositions, mergers, entry into other lines of business, investments and the incurrence of additional indebtedness. The debt to capitalization ratios are calculated on a combined basis with Sharyland. SDTS’s Series A Notes and Series B Notes are not required to maintain a debt service coverage ratio. As of March 31, 2019 and December 31, 2018, SDTS and TDC were in compliance with all debt covenants under the applicable agreements. See Note 2, Pending Corporate Transactions SDTS’s Series A Notes, Series B Notes, 2009 Notes, 2010 Notes and 2017 Term Loan are secured by certain of SDTS’s regulated assets, the leases, certain accounts and TDC’s equity interests in SDTS on the same basis as SDTS’s revolving credit facility described above in Note 8, Borrowings Under Credit Facilities The senior secured notes of TDC and SDTS and 2017 Term Loan are subject to customary events of default. If an event of default occurs with respect to the notes and is continuing, the lenders may accelerate the applicable amounts due.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	10 . Fair Value of Financial Instruments The carrying amounts of our cash and cash equivalents, restricted cash, due from affiliates and accounts payable approximate fair value due to the short-term nature of these assets and liabilities. We had fixed interest rate borrowings totaling $639.2 million and $641.3 million under our senior secured notes with a weighted average interest rate of 4.5% per annum as of March 31, 2019 and December 31, 2018. The fair value of these borrowings was estimated using discounted cash flow analysis based on current market rates. As of March 31, 2019 and December 31, 2018, we had $200.0 million of borrowings under our 2017 Term Loan that accrues interest under a floating interest rate structure, which is typically repriced every month or three months. Accordingly, the carrying value of such indebtedness approximated its fair value for the amounts outstanding. Financial instruments, measured at fair value, by level within the fair value hierarchy were as follows: Carrying Fair Value (In thousands) Value Level 1 Level 2 Level 3 March 31, 2019 Long-term debt $ 839,161 $ — $ 882,033 $ — December 31, 2018 Long-term debt $ 841,311 $ — $ 864,281 $ —

Regulatory Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2019
Public Utilities Rate Matters [Abstract]
Regulatory Matters	1 1 . Regulatory Matters Regulatory Liability Regulatory liabilities are as follows: (In thousands) March 31, 2019 December 31, 2018 Cost of removal $ 63,583 $ 59,753 Excess accumulated deferred federal income tax 55,779 55,779 Regulatory liabilities $ 119,362 $ 115,532 Our regulatory liability related to cost of removal is established through depreciation rates and represents amounts that we expect to incur in the future. The regulatory liability is recorded as a long-term liability net of actual removal costs incurred. As an owner of regulated utility assets, we established an accumulated deferred federal income tax (ADFIT) balance for regulatory purposes primarily associated with the difference between U.S. GAAP and federal income tax depreciation on our assets. Prior to the enactment of the Tax Cuts and Jobs Act (TCJA) in December 2017, this ADFIT was calculated based on a 35% corporate federal income tax rate but was not recorded on our consolidated balance sheets or income statements due to the expectation that we would not pay corporate federal income taxes as a result of our real estate investment trust (REIT) structure. With the passage of the TCJA, the corporate federal income tax rate was reduced to 21% effective for tax years beginning on or after January 1, 2018. Regulatory accounting rules require utilities to revalue their ADFIT balances based on a change in corporate federal income tax rates, to remove the difference from ADFIT and to create a regulatory liability for the reduction in ADFIT. Therefore, we reduced the ADFIT by $55.8 million and created a regulatory liability for regulatory purposes. Additionally, in accordance with Accounting Standards Codification Topic 980, Regulated Operations Liabilities Rate Setting We have separated, between Sharyland and SDTS, the functionality that is typically combined under one commonly owned group in an integrated utility. SDTS is generally responsible for financing and funding asset additions, while Sharyland is responsible for construction management, operation and maintenance of our regulated assets. Accordingly, the PUCT’s order approving our restructuring into a REIT structure required Sharyland and SDTS to be regulated on a combined basis, and Sharyland, as the holder of the certificate of convenience and necessity (CCN) required to operate our regulated assets, historically has made all regulatory filings related to our assets with the PUCT. As part of the rate case in Docket No. 45414 related to SDTS’s assets (2016 Rate Case), the PUCT raised certain questions indicating that this regulatory construct might change in the future, including the potential regulation of the leases between Sharyland and SDTS as tariffs. In November 2017, the 2016 Rate Case was dismissed upon the completion of the 2017 Asset Exchange Transaction (Rate Case Dismissal), but the dismissal preserved the right of the parties to the 2016 Rate Case to address in a future proceeding all issues not mooted by the Rate Case Dismissal. Additionally, as part of the PUCT order approving the 2017 Asset Exchange Transaction, SDTS was granted a separate CCN to continue to own and lease its assets to Sharyland. The regulatory parameters in Sharyland’s rates and applicable to our regulated assets provide for a capital structure consisting of 55% debt and 45% equity, a cost of debt of 6.73%, a return on equity of 9.70% and a return on invested capital of 8.06% in calculating rates. Additionally, Sharyland’s rates also reflect the recovery of an income tax allowance, with respect to our transmission assets, at the 21% corporate federal income tax rate and, with respect to our wholesale distribution assets, at the prior 35% corporate federal income tax rate. Under existing PUCT orders, SDTS and Sharyland are required to file a new rate case by July 1, 2020 using the test year ending December 31, 2019. If the sale of InfraREIT is not completed and we are required to move forward with the 2020 rate case, the outcome of that rate case will result in an adjustment to many of the current parameters applicable to our regulated assets.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 2 . Commitments and Contingencies From time to time, we are a party to various legal proceedings arising in the ordinary course of business. Although we cannot predict the outcome of any such legal proceedings, we do not believe the resolution of these proceedings, individually or in the aggregate, will have a material impact on our business, financial condition or results of operations, liquidity or cash flows.

Equity

Equity	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Equity	1 3 . Equity We and the Operating Partnership declared cash dividends on common stock and distributions on OP Units of $0.25 per share or unit, as applicable, during each of the three months ended March 31, 2019 and 2018. We paid a total of $15.2 million in dividends and distributions during each of the three months ended March 31, 2019 and 2018.

Noncontrolling Interest

Noncontrolling Interest	3 Months Ended
	Mar. 31, 2019
Noncontrolling Interest [Abstract]
Noncontrolling Interest	1 4 . Noncontrolling Interest We present as a noncontrolling interest the portion of any equity in entities that we control and consolidate but do not own. Generally, OP Units of the Operating Partnership participate in net income allocations and distributions and entitle their holder to the right, subject to the terms set forth in the partnership agreement, to require the Operating Partnership to redeem all or a portion of the OP Units held by such limited partner. At our option, we may satisfy this redemption requirement with cash or by exchanging shares of our common stock on a one-for-one basis. As of March 31, 2019 and December 31, 2018, there were a total of 16.7 million OP Units held by the limited partners of the Operating Partnership. During the three months ended March 31, 2018, an aggregate of 28,952 long-term incentive units (LTIP Units) were issued by the Operating Partnership to members of our board of directors. There were no LTIP Units issued during the three months ended March 31, 2019. For additional information, refer to Note 17, Share-Based Compensation We follow the guidance issued by the FASB regarding the classification and measurement of redeemable securities. Accordingly, we have determined that the OP Units meet the requirements to be classified as permanent equity. During the three months ended March 31, 2019, we redeemed 7,698 OP Units with the issuance of 7,698 shares of common stock. We redeemed 163,969 OP Units with the issuance of 163,969 shares of common stock during the three months ended March 31, 2018.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	1 5 . Earnings Per Share Basic earnings per share is calculated by dividing net earnings after noncontrolling interest by the weighted average shares outstanding. Diluted earnings per share is calculated similarly, except that it includes the dilutive effect of the assumed redemption of OP Units for shares of our common stock, if such redemption were dilutive. The redemption of OP Units would have been anti-dilutive during the three months ended March 31, 2019 and 2018. Earnings per share are calculated as follows: Three Months Ended March 31, (In thousands, except per share data) 2019 2018 Basic net income per share: Net income attributable to InfraREIT, Inc. $ 13,745 $ 12,864 Weighted average common shares outstanding 43,998 43,832 Basic net income per share $ 0.31 $ 0.29 Diluted net income per share: Net income attributable to InfraREIT, Inc. $ 13,745 $ 12,864 Weighted average common shares outstanding 43,998 43,832 Redemption of Operating Partnership units — — Weighted average dilutive shares outstanding 43,998 43,832 Diluted net income per share $ 0.31 $ 0.29 Due to the anti-dilutive effect, the computation of diluted earnings per share does not reflect the following adjustments: Net income attributable to noncontrolling interest $ 5,224 $ 4,900 Redemption of Operating Partnership units 16,729 16,872

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	1 6 . Leases Leases with SDTS as Lessor As part of the adoption of Topic 842, we elected to not reassess the lease classification for any expired or existing leases; therefore, all of the leases for our regulated assets will continue to be classified as operating leases. Additionally, we have elected to exclude lessor costs paid directly by Sharyland to third parties on our behalf from consideration in the contracts and from variable payments. The following table shows the composition of our lease revenue: Three Months Ended March 31, (In thousands) 2019 2018 Base rent (straight-line) $ 48,574 $ 45,656 Percentage rent — — Total lease revenue $ 48,574 $ 45,656 SDTS has entered into various leases with Sharyland for all our placed in service regulated assets. The master lease agreements, as amended, expire at various dates from December 31, 2019 through December 31, 2022. Our leases primarily consist of base rent, but certain lease supplements contain percentage rent as well. All of the rent with respect to the capital expenditures to be placed in service in 2019 consist only of base rent. Percentage rent under our leases is based on a percentage of Sharyland’s annual gross revenue, as defined in the applicable lease, in excess of an annual breakpoint specified in each lease, which are at least equal to the base rent under each lease. The rate used for percentage rent for the reported time periods varies by lease and ranges from 26% to 30%. Because an annual specified breakpoint must be met under our leases before we can recognize any percentage rent, we anticipate that revenue will grow over the year with little to no percentage rent recognized in the first and second quarters of each year, with the largest amounts recognized during the third and fourth quarters of each year. Future minimum rent revenue expected in accordance with these lease agreements is as follows for the years ending December 31: (In thousands) Total 2019 $ 194,068 2020 184,438 2021 9,089 2022 4,954 2023 — Thereafter — Total $ 392,549 See Note 2, Pending Corporate Transactions Leases with SDTS as Lessee As part of the adoption of Topic 842, we elected not to reassess existing or expired land easements that were not previously treated as leases; therefore, our existing land easements as of January 1, 2019 will continue to be treated as land and not land leases and will be included in electric plant, net on our Consolidated Balance Sheets. Land easements entered into or modified after January 1, 2019 will be evaluated under Topic 842 to determine if they meet the definition of a lease. We are the lessee under two land leases that are subleased to Sharyland under the master lease agreements described above under the caption Leases with SDTS as Lessor Both land leases are surface leases where the lessor retains the mineral rights. There were no initial direct costs incurred or residual value guarantees provided. The weighted-average remaining lease term is 43.2 years. The following table describes the main attributes of the land leases: Name of Lease Expiration Date Renewal Periods Rent Escalations Initial Annual Rent (In dollars) Brownsville November 1, 2067 None None $ 10,435 Scottish Rite-Rocky Road January 12, 2035 Four 5-year terms 5% increase every 5 years after initial term 8,000 We have recorded the operating lease right-of-use assets in prepaids and other current assets and other assets, and the lease liabilities in accounts payable and accrued liabilities and long-term operating lease liabilities on our Consolidated Balance Sheets as follows: (In thousands) March 31, 2019 Prepaid and other current assets $ 18 Other assets 345 Total right-of-use asset $ 363 Accounts payable and accrued liabilities $ 18 Long-term operating lease liabilities 345 Total operating lease liabilities $ 363 See Note 7, Other Assets In determining the right-of-use assets and operating lease liabilities, we used a discount rate of 4.25%, which is our incremental borrowing rate, and assumed that we would exercise all four five-year term extensions related to the Scottish Rite-Rocky Road lease. Rent expense for these operating leases is recognized on a straight-line basis over the lease term and is included in general and administrative expense on our Consolidated Statements of Operations.

Share Based Compensation

Share Based Compensation	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	1 7 . Share-Based Compensation We currently utilize the InfraREIT, Inc. 2015 Equity Incentive Plan primarily for the annual compensation of the non-executive directors for their service on our board of directors. The following table shows the aggregate common stock issued to members of our board of directors for the three months ended March 31, 2019: Grant Date Shares of Common Stock Grant Date Value per Share Aggregate Fair Value (in thousands) Vesting Date January 2019 22,674 $ 21.15 $ 480 January 2020 There was no common stock issued to our directors during the three months ended March 31, 2018. The following table shows the aggregate LTIP Units issued to members of our board of directors for the three months ended March 31, 2018: Grant Date LTIP Units Grant Date Fair Value per LTIP Unit Aggregate Fair Value (in thousands) Vesting Date January 2018 28,952 $ 18.61 $ 539 January 2019 There were no LTIP Units issued to our directors during the three months ended March 31, 2019. As part of our board of directors’ quarterly compensation, each non-executive director can, subject to certain exceptions, elect to receive part of his or her compensation in our common stock instead of cash with full vesting upon issuance. During 2019 and 2018, all directors received their quarterly compensation in cash. The compensation expense, which represents the fair value of the common stock or LTIP Unit measured at market price at the date of grant, is recognized on a straight-line basis over the vesting period. For each of the three months ended March 31, 2019 and 2018, $0.1 million was recognized as compensation expense related to these grants and is included in general and administrative expense on the Consolidated Statements of Operations. The unamortized compensation expense related to these grants was $0.4 million as of March 31, 2019.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	18. Income Taxes Franchise Taxes Effective January 1, 2018, we began accruing and paying Texas franchise tax on our gross lease revenues. The accrued franchise tax is recorded in accrued taxes on our Consolidated Balance Sheets, while the expense is recognized in income tax expense on our Consolidated Statements of Operations. For each of the three months ended March 31, 2019 and 2018, $0.3 million was recognized related to Texas franchise tax on our gross lease revenues. Tax Cuts and Jobs Act In 2017, the TCJA was signed into law reducing the corporate federal income tax rate from 35% to 21%, effective for taxable years beginning on or after January 1, 2018. As a result of the reduction in the corporate federal income tax rate, we recorded $55.8 million as a regulatory liability on our Consolidated Balance Sheets as of December 31, 2017 related to the creation of excess ADFIT, related to our assets. See Note 11, Regulatory Matters

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	1 9 . Supplemental Cash Flow Information Supplemental cash flow information and non-cash investing and financing activities are as follows: Three Months Ended March 31, (In thousands) 2019 2018 Supplemental cash flow information Cash paid for interest $ 7,832 $ 7,469 Establishment of operating lease right-of-use assets and liabilities 363 — Non-cash investing and financing activities Change in accrued additions to electric plant (242 ) (2,902 ) Allowance for funds used during construction - debt 988 820 Redemption of operating partnership units for common stock 116 3,106 Dividends and distributions payable 15,182 15,176

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	20. Subsequent Events Pending Corporate Transactions In April 2019, the parties to the STM proceeding filed the Settlement with the PUCT reflecting an agreement to settle all outstanding issues in our STM in Docket No. 48929. The Settlement is supported or unopposed by all parties to the STM. The Settlement is subject to review and approval by the PUCT. A hearing on the merits was held on April 10, 2019. We continue to expect the transactions to close by mid-2019, subject to obtaining the PUCT approval and satisfaction of other customary closing conditions.

Description of Business and P_2

Description of Business and Presentation of Financial Statements (Policies)	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation InfraREIT, Inc. is a Maryland corporation, which may be referred to in these financial statements as the “Company,” “InfraREIT,” “we,” “us” and “our.” These unaudited interim consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three months ended March 31, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. For further information, refer to the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2018 filed with the U.S. Securities and Exchange Commission (SEC) on February 27, 2019 (2018 Form 10-K). We hold 72.5% of the outstanding partnership units (OP Units) in InfraREIT Partners, LP (Operating Partnership or InfraREIT LP) as of March 31, 2019 and are its general partner. We include the accounts of the Operating Partnership and its subsidiaries in our consolidated financial statements. Affiliates and current or former employees of Hunt Consolidated, Inc. (Hunt) and members of our board of directors hold the other 27.5% of the outstanding OP Units as of March 31, 2019.
Use of Estimates	Use of Estimates The preparation of our consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
Recent Accounting Guidance	Recent Accounting Guidance Recently Adopted Accounting Guidance In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842 Leases (Topic 842), Narrow-Scope Improvements for Lessors, Leases (Topic 842): Targeted Improvements, Leases Recent Accounting Guidance Not Yet Adopted In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2019
Cash And Cash Equivalents [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash within Consolidated Balance Sheets	The following table provides a reconciliation of cash, cash equivalents and restricted cash within the Consolidated Balance Sheets that sum to the total of the same such amounts shown on the Consolidated Statements of Cash Flows: March 31, (In thousands) 2019 2018 Cash and cash equivalents $ 3,487 $ 1,624 Restricted cash 1,693 1,683 Total cash, cash equivalents and restricted cash shown on the Statement of Cash Flows $ 5,180 $ 3,307

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Schedule of Annual Base Fees	The base fees through December 31, 2019 are as follows: (In millions) Base Fee April 1, 2017 - March 31, 2018 $ 14.2 April 1, 2018 - March 31, 2019 13.5 April 1, 2019 - December 31, 2019 10.4

Electric Plant and Depreciati_2

Electric Plant and Depreciation (Tables)	3 Months Ended
	Mar. 31, 2019
Public Utilities Property Plant And Equipment [Abstract]
Schedule of Major Classes of Electric Plant	The major classes of electric plant are as follows: (In thousands) March 31, 2019 December 31, 2018 Electric plant: Transmission plant $ 1,794,442 $ 1,794,438 Distribution plant 151,698 151,698 General plant 3,210 3,023 Total plant in service 1,949,350 1,949,159 Construction work in progress 77,568 66,121 Total electric plant 2,026,918 2,015,280 Accumulated depreciation (212,334 ) (203,963 ) Electric plant, net $ 1,814,584 $ 1,811,317

Other Assets (Tables)

Other Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Summary of Other Assets	Other assets are as follows: March 31, 2019 December 31, 2018 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Deferred financing costs on undrawn revolver $ 1,025 $ (811 ) $ 214 $ 1,025 $ (779 ) $ 246 Other regulatory assets: Deferred financing costs 10,610 (5,810 ) 4,800 10,610 (5,490 ) 5,120 Deferred costs recoverable in future years 23,793 — 23,793 23,793 — 23,793 Other regulatory assets 34,403 (5,810 ) 28,593 34,403 (5,490 ) 28,913 Operating lease right-of-use asset 345 — 345 — — — Investments 2,519 — 2,519 2,519 — 2,519 Other assets $ 38,292 $ (6,621 ) $ 31,671 $ 37,947 $ (6,269 ) $ 31,678

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Instruments [Abstract]
Components of Long-Term Debt	Long-term debt consisted of the following: March 31, 2019 December 31, 2018 (Dollar amounts in thousands) Maturity Date Amount Outstanding Interest Rate Amount Outstanding Interest Rate TDC Senior secured notes - $25.0 million December 30, 2020 $ 14,687 8.50% $ 15,000 8.50% SDTS Senior secured term loan - $200.0 million June 5, 2020 200,000 3.74% 200,000 3.73% Senior secured notes - $400.0 million December 3, 2025 400,000 3.86% 400,000 3.86% Senior secured notes - $100.0 million January 14, 2026 100,000 3.86% 100,000 3.86% Senior secured notes - $53.5 million December 30, 2029 37,762 7.25% 38,338 7.25% Senior secured notes - $110.0 million September 30, 2030 86,712 6.47% 87,973 6.47% Total SDTS debt 824,474 826,311 Total long-term debt 839,161 841,311 Less unamortized deferred financing costs (57 ) (64 ) Total long-term debt, less deferred financing costs 839,104 841,247 Less current portion of long-term debt (8,919 ) (8,792 ) Debt classified as long-term debt, less deferred financing costs $ 830,185 $ 832,455

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Financial Instruments Measured at Fair Value	Financial instruments, measured at fair value, by level within the fair value hierarchy were as follows: Carrying Fair Value (In thousands) Value Level 1 Level 2 Level 3 March 31, 2019 Long-term debt $ 839,161 $ — $ 882,033 $ — December 31, 2018 Long-term debt $ 841,311 $ — $ 864,281 $ —

Regulatory Matters (Tables)

Regulatory Matters (Tables)	3 Months Ended
	Mar. 31, 2019
Public Utilities Rate Matters [Abstract]
Summary of Regulatory Liabilities	Regulatory liabilities are as follows: (In thousands) March 31, 2019 December 31, 2018 Cost of removal $ 63,583 $ 59,753 Excess accumulated deferred federal income tax 55,779 55,779 Regulatory liabilities $ 119,362 $ 115,532

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Computation of Earnings Per Share	Earnings per share are calculated as follows: Three Months Ended March 31, (In thousands, except per share data) 2019 2018 Basic net income per share: Net income attributable to InfraREIT, Inc. $ 13,745 $ 12,864 Weighted average common shares outstanding 43,998 43,832 Basic net income per share $ 0.31 $ 0.29 Diluted net income per share: Net income attributable to InfraREIT, Inc. $ 13,745 $ 12,864 Weighted average common shares outstanding 43,998 43,832 Redemption of Operating Partnership units — — Weighted average dilutive shares outstanding 43,998 43,832 Diluted net income per share $ 0.31 $ 0.29 Due to the anti-dilutive effect, the computation of diluted earnings per share does not reflect the following adjustments: Net income attributable to noncontrolling interest $ 5,224 $ 4,900 Redemption of Operating Partnership units 16,729 16,872

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Schedule of Composition of Lease Revenue	The following table shows the composition of our lease revenue: Three Months Ended March 31, (In thousands) 2019 2018 Base rent (straight-line) $ 48,574 $ 45,656 Percentage rent — — Total lease revenue $ 48,574 $ 45,656
Schedule of Future Minimum Rent Revenue Expected in Accordance with Lease Agreement	Future minimum rent revenue expected in accordance with these lease agreements is as follows for the years ending December 31: (In thousands) Total 2019 $ 194,068 2020 184,438 2021 9,089 2022 4,954 2023 — Thereafter — Total $ 392,549
Schedule of Land Leases	The following table describes the main attributes of the land leases: Name of Lease Expiration Date Renewal Periods Rent Escalations Initial Annual Rent (In dollars) Brownsville November 1, 2067 None None $ 10,435 Scottish Rite-Rocky Road January 12, 2035 Four 5-year terms 5% increase every 5 years after initial term 8,000
Schedule of Right-of-use Assets and Operating Lease Liabilities	We have recorded the operating lease right-of-use assets in prepaids and other current assets and other assets, and the lease liabilities in accounts payable and accrued liabilities and long-term operating lease liabilities on our Consolidated Balance Sheets as follows: (In thousands) March 31, 2019 Prepaid and other current assets $ 18 Other assets 345 Total right-of-use asset $ 363 Accounts payable and accrued liabilities $ 18 Long-term operating lease liabilities 345 Total operating lease liabilities $ 363

Share-Based Compensation (Table

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Aggregate Common Stock Issued to Members of Board of Directors	The following table shows the aggregate common stock issued to members of our board of directors for the three months ended March 31, 2019: Grant Date Shares of Common Stock Grant Date Value per Share Aggregate Fair Value (in thousands) Vesting Date January 2019 22,674 $ 21.15 $ 480 January 2020
Aggregate LTIP Units Issued to Board of Directors	The following table shows the aggregate LTIP Units issued to members of our board of directors for the three months ended March 31, 2018: Grant Date LTIP Units Grant Date Fair Value per LTIP Unit Aggregate Fair Value (in thousands) Vesting Date January 2018 28,952 $ 18.61 $ 539 January 2019

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information and Non-cash Investing and Financing Activities	Supplemental cash flow information and non-cash investing and financing activities are as follows: Three Months Ended March 31, (In thousands) 2019 2018 Supplemental cash flow information Cash paid for interest $ 7,832 $ 7,469 Establishment of operating lease right-of-use assets and liabilities 363 — Non-cash investing and financing activities Change in accrued additions to electric plant (242 ) (2,902 ) Allowance for funds used during construction - debt 988 820 Redemption of operating partnership units for common stock 116 3,106 Dividends and distributions payable 15,182 15,176

Description of Business and P_3

Description of Business and Presentation of Financial Statements - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019
Description Of Business And Presentation Of Financial Statements [Line Items]
Right-of-use assets	$ 363
Operating lease liabilities	$ 363
ASU 2016-02
Description Of Business And Presentation Of Financial Statements [Line Items]
Right-of-use assets		$ 400
Operating lease liabilities		$ 400
InfraREIT LP
Description Of Business And Presentation Of Financial Statements [Line Items]
Percentage of partnership units outstanding	72.50%
Hunt Consolidated, Inc. | InfraREIT LP
Description Of Business And Presentation Of Financial Statements [Line Items]
Percentage of partnership units outstanding	27.50%

Pending Corporate Transactions

Pending Corporate Transactions - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Oct. 18, 2018
Business Acquisition [Line Items]
Expenses on sale of business and related transactions		$ 0
General And Administrative Expense
Business Acquisition [Line Items]
Expenses on sale of business and related transactions	$ 1,700,000
Sharyland Holdings, LP | Sempra Energy
Business Acquisition [Line Items]
Equity interest percentage	50.00%
Hunt Consolidated, Inc.
Business Acquisition [Line Items]
Termination fee related to Sale of InfraREIT, Inc	$ 40,500,000
Oncor Electric Delivery Company LLC | Definitive Agreement
Business Acquisition [Line Items]
Business acquisition, share price			$ 21
Business acquisition, value in cash			$ 1,275,000,000
Business combination, assumption of net debt	$ 940,000,000

Cash, Cash Equivalents and Re_3

Cash, Cash Equivalents and Restricted Cash - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash within Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Cash And Cash Equivalents [Abstract]
Cash and cash equivalents	$ 3,487	$ 1,808	$ 1,624
Restricted cash	1,693	1,689	1,683
Total cash, cash equivalents and restricted cash shown on the Statement of Cash Flows	$ 5,180	$ 3,497	$ 3,307	$ 4,550

Cash, Cash Equivalents and Re_4

Cash, Cash Equivalents and Restricted Cash - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2010
Transmission and Distribution Company, L.L.C | Senior Secured Notes, 8.50%
Restricted Cash And Cash Equivalents Items [Line Items]
Long-term debt, face amount	$ 25	$ 25

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2020	Dec. 31, 2018
Related Party Transaction [Line Items]
Due from affiliates	$ 33,126,000			$ 38,174,000
Hunt Utility Services, LLC
Related Party Transaction [Line Items]
Payment for management fee	3,400,000	$ 3,500,000
Prepaid management fee	0			0
Accrued management fee	0			0
Reimbursement of annual software license and maintenance fees and other expenses	$ 100,000
Type of Cost, Good or Service [Extensible List]	us-gaap:LicenseAndMaintenanceMember	us-gaap:LicenseAndMaintenanceMember
Management agreement expiration date	Dec. 31, 2019
Agreement successive renewal terms	5 years
Management fee, description	The base fee for each 12-month period beginning each April 1 will equal 1.50% of our total equity as of December 31 of the immediately preceding year, subject to a $30.0 million cap
Investment management fee equity multiplier	1.50%
Management fee cap	$ 30,000,000
Hunt Utility Services, LLC | Scenario, Forecast
Related Party Transaction [Line Items]
Due to related parties			$ 3,500,000
Hunt Utility Services, LLC | Maximum
Related Party Transaction [Line Items]
Reimbursement of annual software license and maintenance fees and other expenses		$ 100,000
Sharyland
Related Party Transaction [Line Items]
Lease revenue from related party	48,600,000	45,700,000
Deferred rent liability	9,800,000			11,100,000
Payments to acquire plant, and equipment	9,900,000	$ 15,000,000
Accounts payable and accrued liabilities	3,200,000			2,900,000
Due from affiliates	33,100,000			$ 38,200,000
Termination Fee | Hunt Utility Services, LLC
Related Party Transaction [Line Items]
Due to related parties	41,100,000
Hunt Consolidated, Inc.
Related Party Transaction [Line Items]
Termination fee related to Sale of InfraREIT, Inc	$ 40,500,000

Related Party Transactions - Sc

Related Party Transactions - Schedule of Annual Base Fees (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Dec. 31, 2019	Mar. 31, 2019	Mar. 31, 2018
Related Party Transaction [Line Items]
Annual base fees		$ 13.5	$ 14.2
Scenario, Forecast
Related Party Transaction [Line Items]
Annual base fees	$ 10.4

Electric Plant and Depreciati_3

Electric Plant and Depreciation - Schedule of Major Classes of Electric Plant (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Electric plant:
Transmission plant	$ 1,794,442	$ 1,794,438
Distribution plant	151,698	151,698
General plant	3,210	3,023
Total plant in service	1,949,350	1,949,159
Construction work in progress	77,568	66,121
Total electric plant	2,026,918	2,015,280
Accumulated depreciation	(212,334)	(203,963)
Electric plant, net	$ 1,814,584	$ 1,811,317

Electric Plant and Depreciati_4

Electric Plant and Depreciation - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Public Utilities Property Plant And Equipment [Abstract]
Electric plant, net includes plant acquisition adjustments	$ 28.2	$ 28.5

Goodwill - Additional Informati

Goodwill - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	$ 138,384	$ 138,384

Other Assets - Summary of Other

Other Assets - Summary of Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Assets Noncurrent [Abstract]
Deferred financing costs on undrawn revolver, Gross Carrying Amount	$ 1,025	$ 1,025
Other regulatory assets Deferred financing costs, Gross Carrying Amount	10,610	10,610
Other regulatory assets Deferred costs recoverable in future years, Gross Carrying Amount	23,793	23,793
Other regulatory assets, Gross Carrying Amount	34,403	34,403
Operating lease right-of-use asset, Gross Carrying Amount	345
Investments, Gross Carrying Amount	2,519	2,519
Other assets, Gross Carrying Amount	38,292	37,947
Deferred financing costs on undrawn revolver, Accumulated Amortization	(811)	(779)
Other regulatory assets Deferred financing costs, Accumulated Amortization	(5,810)	(5,490)
Other regulatory assets, Accumulated Amortization	(5,810)	(5,490)
Other assets, Accumulated Amortization	(6,621)	(6,269)
Deferred financing costs on undrawn revolver, Net Carrying Amount	214	246
Other regulatory assets Deferred financing costs, Net Carrying Amount	4,800	5,120
Other regulatory assets Deferred costs recoverable in future years, Net Carrying Amount	23,793	23,793
Other regulatory assets, Net Carrying Amount	28,593	28,913
Operating lease right-of-use asset, Net Carrying Amount	345
Investments, Net Carrying Amount	2,519	2,519
Other assets, Net Carrying Amount	$ 31,671	$ 31,678

Other Assets - Additional Infor

Other Assets - Additional Information (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2019USD ($)Lease	Dec. 31, 2018USD ($)
Other Assets Noncurrent [Abstract]
Deferred costs recoverable in future years	$ 23,793,000	$ 23,793,000
Investment impaired	$ 0	$ 0
Number of land leases | Lease	2

Borrowings Under Credit Facil_2

Borrowings Under Credit Facilities - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended	12 Months Ended
	Dec. 31, 2018	Nov. 30, 2018	Mar. 31, 2019	Dec. 31, 2014
InfraREIT LP Revolving Credit Facility
Line Of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity				$ 75,000,000
Credit facility, maturity date	Dec. 10, 2019			Dec. 10, 2019
Credit facility, remaining borrowing capacity	$ 75,000,000		$ 75,000,000
Revolving credit facility, interest rate description			a rate equal to (1) the one, two, three or six month London Interbank Offered Rate (LIBOR) plus 2.5%, or (2) a base rate (equal to the highest of (a) the Federal Funds Rate plus ½ of 1%, (b) the administrative agent’s prime rate and (c) LIBOR plus 1%) plus 1.5%. Letters of credit are subject to a letter of credit fee equal to the daily amount available to be drawn times 2.5%.
Letter of credit fee multiplier				2.50%
Amount of revolving credit facility under agreement	0		$ 0
Letters of credit outstanding amount	0		0
InfraREIT LP Revolving Credit Facility | One, Two, Three or Six Month London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				2.50%
InfraREIT LP Revolving Credit Facility | Federal Funds Rate
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				0.50%
InfraREIT LP Revolving Credit Facility | LIBOR
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				1.00%
InfraREIT LP Revolving Credit Facility | Base Rate
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				1.50%
InfraREIT LP Revolving Credit Facility | Amendment
Line Of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 67,000,000
Credit facility, maturity date	Dec. 10, 2020
Credit facility, remaining borrowing capacity	$ 8,000,000
InfraREIT LP Revolving Credit Facility | Letter Of Credit
Line Of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity				$ 15,000,000
Third Amended and Restated Credit Agreement | SDTS
Line Of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity				250,000,000
Credit facility, maturity date	Dec. 10, 2020	Dec. 10, 2019
Third Amended and Restated Credit Agreement | Letter Of Credit | SDTS
Line Of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity				25,000,000
Third Amended and Restated Credit Agreement | Swingline Loans | SDTS
Line Of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity				$ 5,000,000
Revolving Credit Facility | SDTS
Line Of Credit Facility [Line Items]
Credit facility, remaining borrowing capacity	$ 137,500,000		$ 143,500,000
Revolving credit facility, interest rate description			a rate equal to either (1) a base rate, determined as the greatest of (a) the administrative agent’s prime rate, (b) the federal funds effective rate plus ½ of 1% and (c) LIBOR plus 1.00% per annum, plus a margin of either 0.75% or 1.00% per annum, depending on the total debt to capitalization ratio of SDTS on a consolidated basis or (2) LIBOR plus a margin of either 1.75% or 2.00% per annum
Amount of revolving credit facility under agreement	$ 112,500,000		$ 106,500,000
Debt, weighted average interest rate	4.59%		4.49%
Revolving Credit Facility | Federal Funds Rate | SDTS
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				0.50%
Revolving Credit Facility | LIBOR | SDTS
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				1.00%
Revolving Credit Facility | LIBOR | SDTS | Minimum
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				1.75%
Revolving Credit Facility | LIBOR | SDTS | Maximum
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				2.00%
Revolving Credit Facility | Base Rate | SDTS | Minimum
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				0.75%
Revolving Credit Facility | Base Rate | SDTS | Maximum
Line Of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate				1.00%
Revolving Credit Facility | Letter Of Credit | SDTS
Line Of Credit Facility [Line Items]
Amount of revolving credit facility under agreement	$ 0		$ 0

Long-Term Debt - Components of

Long-Term Debt - Components of Long-Term Debt (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2010	Dec. 31, 2009
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 839,161	$ 841,311
Less unamortized deferred financing costs	(57)	(64)
Total long-term debt, less deferred financing costs	839,104	841,247
Less current portion of long-term debt	(8,919)	(8,792)
Debt classified as long-term debt, less deferred financing costs	830,185	832,455
TDC | Senior Secured Notes, 8.50%
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 14,687	$ 15,000
Interest bearing note, maturity date	Dec. 30, 2020
Long-term debt, Interest Rate	8.50%	8.50%	8.50%
SDTS
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 824,474	$ 826,311
SDTS | Senior Secured Term Loan
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 200,000	$ 200,000
Interest bearing note, maturity date	Jun. 5, 2020
Long-term debt, Interest Rate	3.74%	3.73%
SDTS | Senior Secured Notes, 3.86%
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 400,000	$ 400,000
Interest bearing note, maturity date	Dec. 3, 2025
Long-term debt, Interest Rate	3.86%	3.86%
SDTS | Senior Secured Notes, 3.86% Maturing in 2026
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 100,000	$ 100,000
Interest bearing note, maturity date	Jan. 14, 2026
Long-term debt, Interest Rate	3.86%	3.86%
SDTS | Senior Secured Notes, 7.25%
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 37,762	$ 38,338
Interest bearing note, maturity date	Dec. 30, 2029
Long-term debt, Interest Rate	7.25%	7.25%		7.25%
SDTS | Senior Secured Notes, 6.47%
Debt Instrument [Line Items]
Long-term debt, Amount Outstanding	$ 86,712	$ 87,973
Interest bearing note, maturity date	Sep. 30, 2030
Long-term debt, Interest Rate	6.47%	6.47%	6.47%

Long-Term Debt - Components o_2

Long-Term Debt - Components of Long-Term Debt (Parenthetical) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2010	Dec. 31, 2009
TDC | Senior Secured Notes, 8.50%
Debt Instrument [Line Items]
Long-term debt, face amount	$ 25	$ 25
SDTS | Senior Secured Term Loan
Debt Instrument [Line Items]
Long-term debt, face amount	200
SDTS | Senior Secured Notes, 3.86%
Debt Instrument [Line Items]
Long-term debt, face amount	400
SDTS | Senior Secured Notes, 3.86% Maturing in 2026
Debt Instrument [Line Items]
Long-term debt, face amount	100
SDTS | Senior Secured Notes, 7.25%
Debt Instrument [Line Items]
Long-term debt, face amount	53.5		$ 53.5
SDTS | Senior Secured Notes, 6.47%
Debt Instrument [Line Items]
Long-term debt, face amount	$ 110	$ 110

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2010	Dec. 31, 2009
Debt Instrument [Line Items]
Deferred financing costs, Net Carrying Amount	$ 214		$ 246
2017 Term Loan
Debt Instrument [Line Items]
Long-term debt, face amount	200,000		$ 200,000
TDC | Senior Secured Notes, 8.50%
Debt Instrument [Line Items]
Long-term debt, face amount	$ 25,000					$ 25,000
Long-term debt, stated interest rate	8.50%		8.50%			8.50%
Deferred financing costs, Net Carrying Amount	$ 100		$ 100
SDTS | 2017 Term Loan | Canadian Imperial Bank of Commerce, New York Branch and Mizuho Bank, Ltd.
Debt Instrument [Line Items]
Long-term debt, face amount		$ 200,000
Interest rate description	The interest rate for the 2017 Term Loan is based, at SDTS’s option, at a rate equal to either (1) a base rate, determined as the greatest of (a) the administrative agent’s prime rate, (b) the federal funds effective rate plus 0.5% and (c) LIBOR plus 1.00% per annum, plus a margin of 0.25% per annum or (2) LIBOR plus a margin of 1.25% per annum. The LIBOR interest period may be one, two, three or six months, but interest is payable no less frequently than quarterly.
SDTS | 2017 Term Loan | Canadian Imperial Bank of Commerce, New York Branch and Mizuho Bank, Ltd. | Federal Funds Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.50%
SDTS | 2017 Term Loan | Canadian Imperial Bank of Commerce, New York Branch and Mizuho Bank, Ltd. | LIBOR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.00%
SDTS | 2017 Term Loan | Canadian Imperial Bank of Commerce, New York Branch and Mizuho Bank, Ltd. | Base Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.25%
SDTS | 2017 Term Loan | Canadian Imperial Bank of Commerce, New York Branch and Mizuho Bank, Ltd. | One, Two, Three or Six Month London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.25%
SDTS | Senior Secured Notes, 7.25%
Debt Instrument [Line Items]
Long-term debt, face amount	$ 53,500						$ 53,500
Long-term debt, stated interest rate	7.25%		7.25%				7.25%
SDTS | Senior Secured Notes, 6.47%
Debt Instrument [Line Items]
Long-term debt, face amount	$ 110,000					$ 110,000
Long-term debt, stated interest rate	6.47%		6.47%			6.47%
SDTS Credit Agreements | Series A Notes
Debt Instrument [Line Items]
Long-term debt, face amount					$ 400,000
Long-term debt, stated interest rate					3.86%
SDTS Credit Agreements | Series B Notes
Debt Instrument [Line Items]
Long-term debt, face amount				$ 100,000
Long-term debt, stated interest rate				3.86%

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term Debt	$ 830,185	$ 832,455
2017 Term Loan
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, face amount	200,000	200,000
Senior Secured Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term Debt	$ 639,200	$ 641,300
Debt, weighted average interest rate	4.50%	4.50%

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Financial Instruments Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Carrying Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-term debt	$ 839,161	$ 841,311
Level 2 | Fair Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-term debt	$ 882,033	$ 864,281

Regulatory Matters - Summary of

Regulatory Matters - Summary of Regulatory Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Public Utilities General Disclosures [Line Items]
Regulatory Liabilities	$ 119,362	$ 115,532
Cost of Removal
Public Utilities General Disclosures [Line Items]
Regulatory Liabilities	63,583	59,753
Excess Accumulated Deferred Federal Income Tax
Public Utilities General Disclosures [Line Items]
Regulatory Liabilities	$ 55,779	$ 55,779	$ 55,800

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Details) - USD ($) $ in Thousands	May 01, 2014	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Public Utilities General Disclosures [Line Items]
Corporate federal income tax rate		21.00%	21.00%	35.00%
Regulatory liability related to creation of excess accumulated deferred federal income tax		$ 55,800		$ 55,800
Regulatory liabilities		119,362	$ 115,532
Sharyland
Public Utilities General Disclosures [Line Items]
Public utilities, approved capital structure, debt percentage	55.00%
Public utilities, approved capital structure, equity percentage	45.00%
Public utilities, approved cost of debt percentage	6.73%
Public utilities, approved return on equity, percentage	9.70%
Public utilities, approved return on invested capital, percentage	8.06%
Excess ADFIT
Public Utilities General Disclosures [Line Items]
Regulatory liabilities		$ 55,779	$ 55,779	$ 55,800

Equity - Additional Information

Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Equity [Abstract]
Cash dividends declared per share to shareholders	$ 0.25	$ 0.25
Cash distributions declared to unit holders, per unit	$ 0.25	$ 0.25
Dividends and distributions paid	$ 15,176	$ 15,169

Noncontrolling Interest - Addit

Noncontrolling Interest - Additional Information (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Minority Interest [Line Items]
Description of units redeemed for cash or, at option, exchanged for common shares	one-for-one basis
OP Units held by the limited partners	16,700,000		16,700,000
Operating partnership units redeem	7,698	163,969
Common shares issued	7,698	163,969
LTIP Units
Minority Interest [Line Items]
Operating partnership units issued	0	28,952

Earnings Per Share - Computatio

Earnings Per Share - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic net income per share:
Net income attributable to InfraREIT, Inc.	$ 13,745	$ 12,864
Weighted average common shares outstanding	43,998	43,832
Basic net income per share	$ 0.31	$ 0.29
Diluted net income per share:
Net income attributable to InfraREIT, Inc.	$ 13,745	$ 12,864
Weighted average common shares outstanding	43,998	43,832
Weighted average dilutive shares outstanding	43,998	43,832
Diluted net income per share	$ 0.31	$ 0.29
Due to the anti-dilutive effect, the computation of diluted earnings per share does not reflect the following adjustments:
Net income attributable to noncontrolling interest	$ 5,224	$ 4,900
Redemption of Operating Partnership units	16,729	16,872

Leases - Schedule of Compositio

Leases - Schedule of Composition of Lease Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Leases [Abstract]
Base rent (straight-line)	$ 48,574	$ 45,656
Total lease revenue	$ 48,574	$ 45,656

Leases - Additional Information

Leases - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019USD ($)Lease
Operating Leased Assets [Line Items]
Operating leases placed in services dates description	SDTS has entered into various leases with Sharyland for all our placed in service regulated assets. The master lease agreements, as amended, expire at various dates from December 31, 2019 through December 31, 2022.
Lease expiration date range, start date	Dec. 31, 2019
Lease expiration date range, end date	Dec. 31, 2022
Number of properties subject to ground leases | Lease	2
Initial direct costs	$ 0
Residual value guarantees	$ 0
Weighted-average remaining lease term	43 years 2 months 12 days
Discount rate	4.25%
Scottish Rite Rocky Road
Operating Leased Assets [Line Items]
Renewal Periods	Four 5-year terms
Operating lease renewal term	5 years
Maximum
Operating Leased Assets [Line Items]
Rate of rent used, Percentage	30.00%
Minimum [Member]
Operating Leased Assets [Line Items]
Rate of rent used, Percentage	26.00%

Leases - Future Minimum Rent Re

Leases - Future Minimum Rent Revenue Expected in Accordance with Lease Agreement (Details) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 194,068
2020	184,438
2021	9,089
2022	4,954
Total	$ 392,549

Leases - Schedule of Land Lease

Leases - Schedule of Land Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Brownsville
Operating Leased Assets [Line Items]
Expiration Date	Nov. 1, 2067
Renewal Periods	None
Rent Escalations	None
Initial Annual Rent (In dollars)	$ 10,435
Scottish Rite Rocky Road
Operating Leased Assets [Line Items]
Expiration Date	Jan. 12, 2035
Renewal Periods	Four 5-year terms
Lessee, Operating Lease, Renewal Term	5 years
Rent Escalations	5% increase every 5 years after initial term
Rent Escalations, Incraese in Percentage	5.00%
Lessee Operating Lease, Rent Escalation Term	5 years
Initial Annual Rent (In dollars)	$ 8,000

Leases - Schedule of Right-of-u

Leases - Schedule of Right-of-use Assets and Operating Lease Liabilities (Details) $ in Thousands	Mar. 31, 2019USD ($)
Lessee Lease Description [Line Items]
Total right-of-use asset	$ 363
Accounts payable and accrued liabilities	$ 18
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent
Long-Term Operating Lease Liabilities	$ 345
Total operating lease liabilities	363
Prepaid and Other Current Assets
Lessee Lease Description [Line Items]
Total right-of-use asset	18
Other Assets
Lessee Lease Description [Line Items]
Total right-of-use asset	$ 345

Share-Based Compensation - Aggr

Share-Based Compensation - Aggregate Common Stock Issued to Members of Board of Directors (Details) - 2015 Equity Incentive Plan - Director $ / shares in Units, $ in Thousands	1 Months Ended
	Jan. 31, 2019USD ($)$ / sharesshares
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Grant Date	2019-01
Shares of Common Stock | shares	22,674
Grant Date Fair Value per Share | $ / shares	$ 21.15
Aggregate Fair Value | $	$ 480
Vesting Date	2020-01

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
2015 Equity Incentive Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Unamortized stock compensation expense	$ 0.4
2015 Equity Incentive Plan | General And Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Compensation expenses	$ 0.1	$ 0.1
Director
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock issued to directors		0
LTIP Units	0

Share-Based Compensation - Ag_2

Share-Based Compensation - Aggregate LTIP Units Issued to Board of Directors (Details) - Director - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Mar. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
LTIP Units			0
2015 Equity Incentive Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Grant Date	2019-01
Grant Date Fair Value per Share	$ 21.15
Aggregate Fair Value	$ 480
Vesting Date	2020-01
2015 Equity Incentive Plan | LTIP Units
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Grant Date		2018-01
LTIP Units		28,952
Grant Date Fair Value per Share		$ 18.61
Aggregate Fair Value		$ 539
Vesting Date		2019-01

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Corporate federal income tax rate	21.00%		21.00%	35.00%
Regulatory liability related to creation of excess accumulated deferred federal income tax	$ 55.8			$ 55.8
Texas
Income Tax Contingency [Line Items]
Franchise taxes on lease revenue	$ 0.3	$ 0.3

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information - Supplemental Cash Flow Information and Non-cash Investing and Financing Activities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Supplemental cash flow information
Cash paid for interest	$ 7,832	$ 7,469
Establishment of operating lease right-of-use assets and liabilities	363
Non-cash investing and financing activities
Change in accrued additions to electric plant	(242)	(2,902)
Allowance for funds used during construction - debt	988	820
Redemption of operating partnership units for common stock	116	3,106
Dividends and distributions payable	$ 15,182	$ 15,176	$ 15,176