Acquisitions and Business Combinations - Schedule of Preliminary Allocation of the Aggregate Purchase Price of these Acquisitions (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2026	Dec. 31, 2025	Dec. 31, 2024
Business Combination [Line Items]
Goodwill	$ 35,468	$ 30,078	$ 30,078
Tax And Law Firm, Consulting Firm And An Accounting Firm
Business Combination [Line Items]
Cash paid including the settlement of debt	9,225
Settlement of pre-existing arrangements	679
Fair value of earnout liability	1,309
Fair value of deferred consideration	13,824
Total purchase price	25,037
Cash and cash equivalents	6,153
Accounts receivable	10,747
Other current assets	2,049
Property and equipment	2,216
Operating lease right-of-use assets	7,319
Other noncurrent assets	175
Customer relationships	8,618
Liabilities assumed, current	(8,941)
Liabilities assumed, noncurrent	(39)
Operating lease liabilities, current	(841)
Operating lease liabilities, noncurrent	(6,389)
Bargain purchase gain	(1,420)
Goodwill	5,390
Total net assets acquired	$ 25,037