Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Statement of Cash Flows [Abstract]
Deferred tax benefit (provision) related to unrealized loss (gain) on investments	$ 205	$ (48)
Deferred tax expense related to postretirement benefits obligation	$ (6)	$ (15)

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

No definition available.

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