Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Statement of Cash Flows [Abstract]
Non cash net unrealized (gain) loss on investments, net of deferred tax benefit (provision)	$ (307)	$ 351

The amount of deferred tax provision resulting from unrealized gains and losses during the period.

No definition available.

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