Name:	itic_FiniteAndIndefiniteLivedIntangibleAssetsGross
Namespace Prefix:	itic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with finite and indefinite lives.

No definition available.

Name:	itic_FiniteAndIndefiniteLivedIntangibleAssetsNet
Namespace Prefix:	itic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Carrying amount as of the balance sheet date for the rights acquired through registration of a trade name to gain or protect exclusive use thereof for both a reasonably expected period of economic benefit and a projected indefinite period of benefit. The carrying amount of finite lived trade names is the gross amount before accumulated amortization as of the balance sheet date. The carrying amount of indefinite lived trade names is the original cost adjusted for previously recognized amortization and impairment as of the balance sheet date.

No definition available.

Name:	itic_FiniteAndIndefiniteLivedTradeNames
Namespace Prefix:	itic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Schedule of Finite-Lived Intangible Assets [Abstract]

No definition available.

Name:	itic_ScheduleofFiniteLivedIntangibleAssetsAbstract
Namespace Prefix:	itic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Gross carrying amount before accumulated amortization as of the balance sheet date to an asset acquired in a business combination representing a favorable existing relationship with customers having a finite beneficial life.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482665/350-30-50-2

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

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(16))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482665/350-30-50-2

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Gross carrying amount before accumulated amortization as of the balance sheet date of payments made to third parties in exchange for their agreement not to engage in specified competitive practices in specified geographic territories for a specified period of time.