Debt instrument periodic payment year and month.

No definition available.

Name:	tntr_DebtInstrumentPeriodicPaymentYearAndMonth
Namespace Prefix:	tntr_
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Balance Type:	na
Period Type:	duration

- Definition

Number of executive employees exercised stock options.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of non-executive employees exercised stock options.

+ References

No definition available.

+ Details

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Namespace Prefix:	tntr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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-SubTopic 30
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
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-Subparagraph (SX 210.7-03.3)
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-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (d)
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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-Paragraph 14
-Subparagraph (a)
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=SL79508275-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new stock issued during the period.

+ 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))
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-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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-Paragraph 1
-Subparagraph (SX 210.5-02(28))
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Topic 210
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Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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- Details

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Related Party and Other Transactions - Additional Information (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($) shares	Jul. 31, 2015 USD ($) shares	Jan. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)	Jan. 31, 2014 USD ($) Employee
Related Party Transaction [Line Items]
Number of executive employees exercised stock options early \| Employee						1
Number of non-executive employees exercised stock options early \| Employee						1
Repayment of outstanding principal and interest balance			$ 470	$ 2,292	$ 3,132
Preferred stock shares, aggregate value			62,314
Series F Convertible Preferred Stock
Related Party Transaction [Line Items]
Preferred stock shares, issued \| shares		11,353
Preferred stock shares, aggregate value		$ 500
Full Recourse Promissory Note \| Executive And Non Executive Employee
Related Party Transaction [Line Items]
Debt instrument principal amount						$ 2,200
Employee notes receivable			$ 700	$ 1,500
Full Recourse Promissory Note \| Non-executive Employee \| Portion of Debt Redemption One
Related Party Transaction [Line Items]
Promissory note and accrued interest payable date						2018-04
Full Recourse Promissory Note \| Non-executive Employee \| Portion of Debt Redemption Two
Related Party Transaction [Line Items]
Promissory note and accrued interest payable date						2019-03
Full Recourse Promissory Note \| Executive Employee
Related Party Transaction [Line Items]
Repayment of outstanding principal and interest balance	$ 1,000
Common stock repurchased \| shares	88,520
Full Recourse Promissory Note \| Minimum \| Executive And Non Executive Employee
Related Party Transaction [Line Items]
Debt instrument interest rate percentage						1.62%
Full Recourse Promissory Note \| Maximum \| Executive And Non Executive Employee
Related Party Transaction [Line Items]
Debt instrument interest rate percentage						1.64%
Promissory Note \| Executive Employee
Related Party Transaction [Line Items]
Debt instrument principal amount						$ 6,600
Debt instrument interest rate percentage						1.92%
Repayment of outstanding principal and interest balance	$ 6,900
Common stock repurchased \| shares	501,104