Defined Benefit Pension Plan - Additional information (Details) - USD ($)	9 Months Ended	12 Months Ended
Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Pension Plan
Assumed discount rate on benefit obligations	4.25%	3.57%	4.25%
Expected long term rate of return		7.00%	7.00%
Annual salary increase	0.00%	0.00%	0.00%
Recognized pension income	$ 4,603	$ 0

The percentage rate of expected long-term rate of return to calculate plan assets.

No definition available.

Name:	tebb_DefinedBenefitPlanPlanAssetsExpectedLongTermRateOfReturn
Namespace Prefix:	tebb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period income related to postemployment benefits.

+ References

No definition available.

+ Details

Name:	tebb_PensionAndOtherPostRetirementBenefitIncome
Namespace Prefix:	tebb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

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

- Definition

Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

+ Details

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