Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022
Statement of Cash Flows [Abstract]
Deferred tax benefit (provision) related to unrealized loss (gain) on investments	$ 40	$ 835
Deferred tax expense related to postretirement benefits obligation	$ (28)	$ (44)

Adjustments To Postretirement Benefits Obligation, Net Of Deferred Tax Benefit Provision

No definition available.

Name:	itic_AdjustmentsToPostretirementBenefitsObligationNetOfDeferredTaxBenefitProvision
Namespace Prefix:	itic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration