Property, Equipment and Software, Net - Summary of Property, Equipment and Software (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Internally developed software	$ 105,978	$ 101,953
Leasehold improvements	36,053	35,140
Computer equipment	29,240	27,030
Purchased software	19,515	19,004
Furniture and fixtures	8,105	8,203
Construction in progress	4,782	2,761
Total property, equipment and software	203,673	194,091
Accumulated depreciation and amortization	(107,600)	(97,450)
Total property, equipment and software, net	96,073	96,641
Construction in Progress
Property, Plant and Equipment [Line Items]
Internally developed software	$ 27,300	$ 13,900

Capitalized Software Development Costs For Internal Use Software

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