Acquisitions - Summary of Components of Purchase Consideration Transferred and Preliminary Allocation of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Cash and stock issued at closing		$ 5,850	$ 0
Allocations
Goodwill		$ 559,214		$ 557,914	$ 515,321
HVS
Business Acquisition [Line Items]
Cash and stock issued at closing	$ 6,249
Contingent consideration	3,590
Total	9,839
Allocations
Goodwill	6,294
Other intangible assets, net	2,700
Receivables, net	796
Fixed Assets, net	134
Other assets	29
Accounts payable, accrued expenses and other liabilities	(114)
Net assets acquired	$ 9,839
2019 Acquisitions
Business Acquisition [Line Items]
Cash and stock issued at closing				38,826
Contingent consideration				18,067
Total				56,893
Allocations
Goodwill				43,804
Cash and cash equivalents				1,391
Other intangible assets, net				9,641
Receivables, net				7,540
Other assets				614
Accounts payable, accrued expenses and other liabilities				(3,972)
Accrued compensation				(2,125)
Net assets acquired				$ 56,893