Name:	us-gaap_ClassOfStockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

Name:	us-gaap_CommonStockSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of equity impact of cash distribution declared to unit-holder of limited partnership (LP).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerCashDistributionsDeclared
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Date of record for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDateOfRecord
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date of declaration for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDeclarationDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date of distribution for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDistributionDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Per unit of ownership amount of cash distributions declared to unit-holder of a limited partnership (LP).

+ References

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

+ References

+ Details

Name:	us-gaap_DividendsCommonStockCash
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Date the dividend to be paid was declared, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ Details

Name:	us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DividendsAxis=hifr_Installment1FY2014Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DividendsAxis=hifr_Installment1FY2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DividendsAxis=hifr_Installment2FY2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_RetainedEarningsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Equity - Additional Information (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended	0 Months Ended
	Mar. 31, 2015	Dec. 18, 2014	Mar. 31, 2015	Jan. 13, 2015	Mar. 06, 2015	Jan. 12, 2015	Jan. 11, 2015
Class Of Stock [Line Items]
Common stock, shares authorized	450,000,000us-gaap_CommonStockSharesAuthorized		450,000,000us-gaap_CommonStockSharesAuthorized			450,000,000us-gaap_CommonStockSharesAuthorized	3,000us-gaap_CommonStockSharesAuthorized
Common stock, par or stated value per share	$ 0.01		$ 0.01			$ 0.01	$ 1
Cash dividends declared per share to shareholders	$ 0.40
Cash Distribution Approved on December 18, 2014
Class Of Stock [Line Items]
Cash distribution declaration date	Dec. 18, 2014
Cash distributions to unit holders, date of record	Dec. 18, 2014
Dividends Payable, date declared	Dec. 18, 2014
Dividends payable date of record	Dec. 18, 2014
Cash dividends declared per share to shareholders		$ 0.31
Cash distribution and dividend paid date	Jan. 16, 2015
Cash Distribution Approved on December 18, 2014 \| InfraREIT, L.L.C.
Class Of Stock [Line Items]
Cash distributions declared to unit holders, per unit		$ 0.31
Cash distribution to unit holders			$ 14.1
Cash Distribution Approved on January 13, 2015
Class Of Stock [Line Items]
Cash distribution declaration date	Jan. 13, 2015
Cash distributions to unit holders, date of record	Jan. 20, 2015
Dividends Payable, date declared	Jan. 13, 2015
Dividends payable date of record	Jan. 20, 2015
Cash dividends declared per share to shareholders				$ 0.26
Cash distribution and dividend paid date	Jan. 29, 2015
Cash Distribution Approved on January 13, 2015 \| InfraREIT, L.L.C.
Class Of Stock [Line Items]
Cash distributions declared to unit holders, per unit				$ 0.26
Cash distribution to unit holders	11.7
Cash Distribution Approved on March 6, 2015
Class Of Stock [Line Items]
Cash distribution declaration date	Mar. 06, 2015
Cash distributions to unit holders, date of record	Mar. 31, 2015
Dividends Payable, date declared	Mar. 06, 2015
Dividends payable date of record	Mar. 31, 2015
Cash dividends declared per share to shareholders					$ 0.14
Cash distribution and dividend paid date	Apr. 23, 2015
Cash Distribution Approved on March 6, 2015 \| InfraREIT, L.L.C.
Class Of Stock [Line Items]
Cash distributions declared to unit holders, per unit					$ 0.14
Cash distribution to unit holders	8.5
Retained Earnings \| Cash Distribution Approved on December 18, 2014
Class Of Stock [Line Items]
Cash dividends declared to shareholders	10.8
Retained Earnings \| Cash Distribution Approved on December 18, 2014 \| InfraREIT, L.L.C.
Class Of Stock [Line Items]
Cash dividends declared to shareholders			10.8
Retained Earnings \| Cash Distribution Approved on January 13, 2015
Class Of Stock [Line Items]
Cash dividends declared to shareholders	9.0
Retained Earnings \| Cash Distribution Approved on January 13, 2015 \| InfraREIT, L.L.C.
Class Of Stock [Line Items]
Cash dividends declared to shareholders	9.0
Retained Earnings \| Cash Distribution Approved on March 6, 2015
Class Of Stock [Line Items]
Cash dividends declared to shareholders	6.1
Retained Earnings \| Cash Distribution Approved on March 6, 2015 \| InfraREIT, L.L.C.
Class Of Stock [Line Items]
Cash dividends declared to shareholders	$ 6.1