Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 81,948	$ 16,400	$ 11,935
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	19,048	13,809	11,140
Provision for doubtful accounts	2,126	1,308	1,066
Share-based compensation	15,916	13,042	10,341
Recovery of key man life insurance			(6,000)
Non-cash interest and other	(12,267)	4,068	456
Effect of foreign currency on operations	(78)	(916)	(769)
Loss (income) from equity investments	1,431	(7,986)	437
Deferred income taxes	10,874	1,990	5,729
Impairment of leaseholds and intangibles, lease loss accrual and gain on disposal of fixed assets	(286)	4,142	3,602
Income allocated and fair value adjustment for mandatorily redeemable noncontrolling interests	1,220	1,222	10,799
Change in operating assets and liabilities:
Due from clearing brokers	13,920	(6,259)	3,359
Securities and other investments owned	(165,765)	(128,217)	(82,143)
Securities borrowed	117,015	(124,257)	47,595
Accounts receivable and advances against customer contracts	(33,927)	(12,948)	1,614
Prepaid expenses and other assets	9,588	(24,395)	(1,506)
Accounts payable, accrued payroll and related expenses, accrued expenses and other liabilities	32,553	3,559	(30,374)
Amounts due to/from related parties and partners	(4,781)	4,705	(11,826)
Securities sold, not yet purchased	4,197	9,332	7,678
Deferred revenue	(3,098)	(564)	(668)
Securities loaned	(120,026)	127,151	(64,255)
Net cash used in operating activities	(30,392)	(104,814)	(81,790)
Cash flows from investing activities:
Purchases of loans receivable	(343,811)	(38,794)
Repayments of loans receivable	159,186
Loan participations sold	31,806
Repayment of loan participations sold	(18,911)
Asset acquisition - Brands, net of cash acquired $2,160	(114,912)
Acquisition of magicJack, net of cash acquired $53,875		(89,240)
Acquisition of Wunderlich, net of cash acquired $4,259			(25,478)
Cash acquired from acquisition of FBR & Co.			15,738
Acquisition of other businesses		(4,000)	(2,052)
Acquisition of United Online, net of cash acquired $125,542 in 2016			(10,381)
Proceeds from sale of division of magicJack	6,196
Purchases of property, equipment and intangible assets	(3,461)	(5,432)	(825)
Proceeds from sale of property, equipment and intangible assets	513	37	836
Proceeds from key man life insurance			6,000
Equity investments	(33,391)	(16,640)	(1,674)
Dividends and distributions from equity investments	21,389	2,628
Net cash used in investing activities	(295,396)	(151,441)	(17,836)
Cash flows from financing activities:
Proceeds from asset based credit facility	140,439	300,000	65,987
Repayment of asset based credit facility	(103,343)	(300,000)	(65,987)
Proceeds from notes payable		51,020
Repayment of notes payable	(478)	(51,713)	(8,336)
Payment of participating note payable and contingent consideration	(4,250)		(1,250)
Proceeds from term loan	10,000	80,000
Repayment of term loan	(22,734)
Proceeds from issuance of senior notes	281,924	258,997	179,471
Redemption of senior notes	(52,154)
Payment of debt issuance costs	(3,425)	(7,260)	(4,289)
Payment of employment taxes on vesting of restricted stock	(2,022)	(3,731)	(3,486)
Common dividends paid	(41,138)	(22,684)	(16,755)
Preferred dividends paid	(264)
Repurchase of common stock	(4,273)	(18,703)
Repurchase of warrants	(2,777)
Distribution to noncontrolling interests	(1,958)	(1,067)	(11,261)
Proceeds from offering common stock	63
Proceeds from offering preferred stock	56,566
Net cash provided by financing activities	250,176	284,859	134,094
(Decrease) increase in cash, cash equivalents and restricted cash	(75,612)	28,604	34,468
Effect of foreign currency on cash, cash equivalents and restricted cash	73	(860)	2,667
Net (decrease) increase in cash, cash equivalents and restricted cash	(75,539)	27,744	37,135
Cash, cash equivalents and restricted cash, beginning of year	180,278	152,534	115,399
Cash, cash equivalents and restricted cash, end of year	104,739	180,278	152,534
Supplemental disclosures:
Interest paid	75,625	50,103	18,840
Taxes paid	$ 8,649	$ 6,497	$ 14,986