RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Due from Related Parties [RollForward]
Related party receivable, beginning balance, December 31, 2019	$ 141,541
Cash transfers	(1,504)
Advisory fees	(2,095)	$ (1,648)
Net income fee	(86)	$ (100)
Cost reimbursements	(1,040)
Interest income	1,817
Notes receivable purchased	(7,368)
Expenses (paid)/received by advisor	(37)
Financing (mortgage payments)	(166)
Intercompany property transfers	(153)
Related party receivable, ending balance, March 31, 2020	130,909
Pillar Income Asset Management, Inc [Member]
Due from Related Parties [RollForward]
Cash transfers	(1,504)
Advisory fees	(2,095)
Net income fee	(86)
Cost reimbursements	(1,040)
Notes receivable purchased	(7,368)
Expenses (paid)/received by advisor	(37)
Financing (mortgage payments)	(166)
Intercompany property transfers	(153)
Related party receivable, ending balance, March 31, 2020	(12,449)
American Realty Investors, Inc [Member]
Due from Related Parties [RollForward]
Related party receivable, beginning balance, December 31, 2019	141,541
Interest income	1,817
Related party receivable, ending balance, March 31, 2020	$ 143,358

The amount of advisory fees to related parties, during the period.

No definition available.

Name:	tci_AdvisoryFeeToRelatedParty
Namespace Prefix:	tci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Refers to due from related party payment for cost of reimbursements.

+ References

No definition available.

+ Details

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Namespace Prefix:	tci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of intercompany property transfers.

+ References

No definition available.

+ Details

Name:	tci_IntercompanyPropertyTransfers
Namespace Prefix:	tci_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Interest income related party receivable.

+ References

No definition available.

+ Details

Name:	tci_InterestIncomeRelatedPartyReceivable
Namespace Prefix:	tci_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of net income fee to related parties during the period.

+ References

No definition available.

+ Details

Name:	tci_NetIncomeFeeToRelatedParty1
Namespace Prefix:	tci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of notes receivable purchased from related parties.

+ References

No definition available.

+ Details

Name:	tci_NotesReceivablePurchasedRelatedParty
Namespace Prefix:	tci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

outflow associated with an amount paid in advance to show an intention to complete a mortgage financing.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash inflow (outflow) from long-term debt by a related party. Related parties, include, but are not limited to, affiliates, owners or officers and their immediate families, and pension trusts.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690

+ Details

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

- Definition

Receivables to be collected from (obligations owed to) related parties, net as of the balance sheet date where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix:
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- Details

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