Description of the Business and Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended
	Jul. 27, 2020 USD ($) $ / shares shares	Sep. 30, 2020 Employee $ / shares shares	Sep. 30, 2020 USD ($) Employee Office Acquisition $ / shares shares	Sep. 30, 2019 USD ($) $ / shares
Description Of Business And Basis Of Presentation [Line Items]
Entity formation, month and year			2013-11
Number of offices in which entity operates | Office			70
Entity number of employees | Employee		1,700	1,700
Number of acquisitions completed | Acquisition			56
Common stock shares sold under IPO | shares	1,786,739
Share price | $ / shares		$ 16.36	$ 16.36	$ 27.30
Net proceeds from sale of common stock			$ 171	$ 139
IPO
Description Of Business And Basis Of Presentation [Line Items]
Common stock shares sold under IPO | shares	11,500,000	11,500,000	11,500,000
Share price | $ / shares	$ 15.00
Net proceeds from sale of common stock	$ 161,300
Underwriting discounts	11,200
Deferred IPO costs againts additional paid in capital	$ 4,400
Underwriters
Description Of Business And Basis Of Presentation [Line Items]
Common stock shares sold under IPO | shares	1,500,000