Lease Commitments - Additional Information (Details) $ in Millions	6 Months Ended
Jun. 30, 2023 USD ($)
Leases [Abstract]
Maximum potential payment increase	5.00%
Legally binding lease payments	$ 1.3

Operating leases, maximum potential existing payment increase.

No definition available.

Name:	ctg_OperatingLeasesMaximumPotentialExistingPaymentIncrease
Namespace Prefix:	ctg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration