Note 3 - Loans Receivable (Details Textual) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Financing Receivable, 90 Days Past Due and Still Accruing, Number of Loans	0	1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		$ 373
Financing Receivable, Modifications, Recorded Investment	$ 4,000	4,100
Financing Receivable, Troubled Debt Restructuring, Number of Contracts	4
Financing Receivable, Troubled Debt Restructuring, Related Allowance	$ 0	$ 0
Financing Receivable, Modifications, Number of Contracts	0	0
Performing Financial Instruments [Member]
Financing Receivable, Modifications, Recorded Investment	$ 3,800	$ 3,900
Financing Receivable, Troubled Debt Restructuring, Number of Contracts	2	2
Nonperforming Financial Instruments [Member]
Financing Receivable, Modifications, Recorded Investment	$ 195	$ 219
Financing Receivable, Troubled Debt Restructuring, Number of Contracts	2	2

Number of loans that are 90 days or more past due and still accruing.

No definition available.

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Namespace Prefix:	hmta_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of troubled debt financing receivables.

+ References

No definition available.

+ Details

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Namespace Prefix:	hmta_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of allowance for credit losses related to troubled debt restructuring.

+ References

No definition available.

+ Details

Name:	hmta_FinancingReceivableTroubledDebtRestructuringRelatedAllowance
Namespace Prefix:	hmta_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Recorded investment in financing receivables that are 90 days or more past due and still accruing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524

+ Details

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Namespace Prefix:	us-gaap_
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- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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