Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($)
Statement Of Stockholders Equity [Abstract]
Accrued compensation expense	$ 1.8

Adjustments to additional paid in capital accrued share-based compensation requisite service period recognition value.

No definition available.

Name:	ttgt_AdjustmentsToAdditionalPaidInCapitalAccruedShareBasedCompensationRequisiteServicePeriodRecognitionValue
Namespace Prefix:	ttgt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration