Loss Per Share - Schedule of Net Loss Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net loss		$ (9,579)	$ (13,057)	$ (15,039)	$ (22,636)	$ (25,527)
Less: Net loss attributable to noncontrolling interests		(4,429)		0	(8,862)	0
Net loss attributable to Definitive Healthcare Corp.		(5,150)		0	(13,774)	0
Basic net loss per share attributable to common stockholders [Abstract]
Allocation of net loss attributable to Definitive Healthcare Corp.		$ (5,150)		$ 0	$ (13,774)	$ 0
Weighted average number of shares of Class A outstanding	[1]	99,203,697			98,186,909
Net loss per share, basic	[1]	$ (0.05)			$ (0.14)
Net loss per share, diluted	[1]	$ (0.05)			$ (0.14)
Common Class A [Member]
Net loss		$ (9,579)			$ (22,636)
Less: Net loss attributable to noncontrolling interests		(4,429)			(8,862)
Net loss attributable to Definitive Healthcare Corp.		(5,150)			(13,774)
Basic net loss per share attributable to common stockholders [Abstract]
Allocation of net loss attributable to Definitive Healthcare Corp.		$ (5,150)			$ (13,774)
Weighted average number of shares of Class A outstanding		99,203,697			98,186,909
Net loss per share, basic		$ (0.05)			$ 0.14
Net loss per share, diluted		$ (0.05)			$ 0.14

[1] (1) Basic and diluted net loss per share of Class A Common Stock is applicable only for the periods beginning from September 15, 2021, which is the period following the IPO and related Reorganization Transactions. See Note 19 for the number of shares used in the computation of net loss per share of Class A Common Stock and the basis for the computation of net loss per share.