Borrowings - Schedule of Long Term Debt (Parenthetical) (Details) $ in Thousands	12 Months Ended
Jun. 30, 2018 USD ($)
Notes Payable One [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	May 31, 2022
Debt Instrument, principal payments	$ 11,270
Debt instrument, variable interest rate	2.25%
Notes Payable Two [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Nov. 01, 2018
Debt Instrument, principal payments	$ 6,535
Debt instrument, variable interest rate	3.75%
Notes Payable Three [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Mar. 15, 2019
Debt Instrument, principal payments	$ 7,783
Debt instrument, variable interest rate	3.75%
Notes Payable Four [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Jul. 01, 2019
Debt Instrument, principal payments	$ 11,267
Debt instrument, variable interest rate	3.90%
Notes Payable Five [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Jul. 01, 2020
Debt Instrument, principal payments	$ 8,729
Debt instrument, variable interest rate	3.95%
Notes Payable Six [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Aug. 20, 2020
Debt Instrument, principal payments	$ 9,701
Debt instrument, variable interest rate	4.25%

The average effective interest rate during the reporting period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

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

- Definition

Amount of the required periodic payments applied to interest.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=thst_NotesPayableToBankOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=thst_NotesPayableToBankTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=thst_NotesPayableToBankThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=thst_NotesPayableToBankFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=thst_NotesPayableToBankFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=thst_NotesPayableToBankSixMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: