Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net income (loss)	$ 7,757	$ (342,755)	$ 48,148
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization of acquired intangible assets	43,426	39,907	44,208
Stock-based compensation	20,754	10,066	16,300
Impairment of goodwill and an intangible asset	0	270,625	50,900
Reduction of right-of-use lease assets	3,046	8,908	4,425
Deferred income taxes	(10,539)	41,059	(67,549)
Amortization of debt discount and issuance costs	2,668	2,065	1,270
Gain on sale of a business	0	(349)	(3,256)
Change in the fair value of acquisition-related contingent consideration	22,400	8,300	0
Accretion of lease liabilities	1,250	1,922	599
Other non-cash expenses	2,602	1,508	135
Changes in operating assets and liabilities, net of acquisitions and disposals:
Accounts receivable, net	(9,152)	10,705	871
Commissions and advisory fees receivable	1,059	(4,956)	(471)
Prepaid expenses and other current assets	(7,438)	3,847	15,043
Other long-term assets	(17,861)	2,232	3,377
Accounts payable	(1,074)	(4,192)	29
Commissions and advisory fees payable	(857)	(884)	432
Lease liabilities	(1,853)	(3,894)	(7,335)
Deferred revenue	(43)	(796)	(17,367)
Accrued expenses and other current and long-term liabilities	(19,314)	761	3,045
Net cash provided by operating activities	36,831	44,079	92,804
Investing activities:
Purchases of property, equipment, and software, net	(30,276)	(36,002)	(10,501)
Business acquisitions, net of cash acquired	0	(101,910)	(166,560)
Asset acquisitions	(8,316)	(3,143)	0
Proceeds from sale of a business, net of cash	0	349	7,467
Net cash used by investing activities	(38,592)	(140,706)	(169,594)
Financing activities:
Proceeds from credit facilities, net of debt discount and issuance costs	(502)	226,278	131,489
Payments on credit facilities	(1,812)	(66,531)	(313)
Acquisition-related contingent consideration payments	(14,075)	0	(943)
Stock repurchases	0	0	(28,399)
Payment of redeemable noncontrolling interests	0	0	(24,945)
Proceeds from stock option exercises	579	97	4,387
Proceeds from issuance of stock through employee stock purchase plan	3,277	2,258	2,212
Tax payments from shares withheld for equity awards	(1,644)	(1,163)	(5,652)
Net cash provided (used) by financing activities	(14,177)	160,939	77,836
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	0	0	38
Net increase (decrease) in cash, cash equivalents, and restricted cash	(15,938)	64,312	1,084
Cash, cash equivalents, and restricted cash, beginning of period	150,762	86,450	85,366
Cash, cash equivalents, and restricted cash, end of period	134,824	150,762	86,450
Supplemental cash flow information:
Cash paid for income taxes	3,056	1,776	3,106
Cash paid for interest	28,897	24,279	18,852
Non-cash investing activities:
Purchases of property, equipment, and software through leasehold incentives	$ 0	$ 9,726	$ 0