Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023
Statement of Cash Flows [Abstract]
Deferred tax benefit (provision) related to unrealized loss (gain) on investments	$ (125)	$ 284
Deferred tax expense related to postretirement benefits obligation	$ 0	$ (27)

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