Acquisitions - Summary of Fair Value of Aggregate Consideration Paid or Payable (Detail) - USD ($) $ in Thousands			12 Months Ended
	Jan. 03, 2019	Jul. 06, 2018	Dec. 31, 2019
SiriusDecisions, Inc [Member]
Business Acquisition [Line Items]
Cash paid at close	$ 246,801
Working capital adjustment	(1,259)
Total	$ 245,542
FeedbackNow [Member]
Business Acquisition [Line Items]
Cash paid at close		$ 8,425	$ 500
Working capital adjustment		798	$ 800
Indemnity holdback		1,485
Contingent purchase price		3,388
Total		$ 14,096