CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (18,328)	$ (21,915)	$ (12,897)	$ (11,545)	$ (58,897)	$ (59,306)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,100		3,800		3,479	11,521
Amortization of right-of-use assets under operating leases	1,800		2,600		6,340	8,107
Amortization of intangible assets	2,673		4,295		8,183	11,344
Unrealized loss on investment in equity securities					0	12,433
Share-based compensation expense	400		1,700		2,510	6,556
Bad debt expense					1,268	1,423	$ 2,229
Amortization of debt discount					499	500
Amortization of debt issuance costs					623	548
Deferred income taxes					8	274
Loss on disposal of fixed assets					117	459
Other non-cash items					137	0
Changes in operating assets and liabilities:
Accounts receivable					1,846	10,136
Prepaid expenses and other current assets					598	621
Other assets					1,439	853
Accounts payable and accrued expenses					(2,738)	(10,676)
Current and non-current operating lease liabilities					(6,958)	(8,518)
Other current and non-current liabilities					413	(352)
Net cash used in operating activities					(41,133)	(14,077)
Cash flows from investing activities:
Additions to premises and equipment					(1,125)	(2,502)
Proceeds from the sale of business					3,000	3,307
Net cash provided by investing activities					1,875	805
Cash flows from financing activities:
Proceeds from revolving credit facility					20,000	0
Debt issuance costs					(531)	0
Proceeds from convertible debt payable to related parties (Note 1)					1,200	0
Distributions to non-controlling interests					(1,804)	(976)
Payments of tax withholding on issuance of restricted share units and restricted shares					(936)	(1,495)
Net cash provided by (used in) financing activities					17,929	(2,471)
Net decrease in cash, cash equivalents and restricted cash					(21,329)	(15,743)
Cash, cash equivalents and restricted cash at the beginning of the period		$ 62,096		$ 86,583	62,096	86,583	86,583
Cash, cash equivalents and restricted cash at the end of the period	$ 40,767		$ 70,840		40,767	70,840	$ 62,096
Supplemental cash flow information:
Interest paid					9,373	12,218
Income taxes paid, net					2,736	742
Acquisition of right-of-use assets with operating lease liabilities					6,976	1,051
Reduction of right-of-use assets from operating lease modifications or reassessments					(5,665)	(1,715)
Non-cash investing and financing activities:
Net (decrease) increase in payables for purchases of premises and equipment					$ (47)	$ 60