Summary of Significant Accounting Policies - Basis of Presentation and Consolidation (Details) $ in Millions	1 Months Ended	6 Months Ended	12 Months Ended
	Apr. 30, 2020	Jun. 26, 2020 segment Market	Dec. 31, 2020 USD ($)
Description of the nature of an event or transaction	Through the date of this filing, about 10% of the Company’s billable resources have been idled since the beginning of the COVID-19 pandemic in March 2020. To offset this reduction in billable resources, during April 2020, the Company took a number of actions to reduce costs and mitigate the potential impact of the COVID-19 pandemic, including a full-time furlough of about 5% of its North American non-billable staff, and a reduced work schedule (20% furlough) for nearly all other non-billable staff, including senior management, that are not directly or indirectly related to business development.
Separate lease transaction for new office space	In addition, the Company subsequently entered into a 10-year lease agreement for its new headquarters in Buffalo, NY. This agreement includes expected lease payments totaling $3.7 million for the signed lease, which has not yet commenced. The Company expects to occupy its new space by December 31, 2020.
Number of operating segments | segment		1
Number of vertical market focus areas | Market		5
Scenario Forecast [Member]
Term of contract, lease			10 years
Lease payments yet to commence | $			$ 3.7