Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Trading income, net	$ 136,163	$ 166,547	$ 275,737	$ 352,836
Interest and dividends income	5,629	5,422	10,503	9,690
Technology services	3,107	2,212	5,886	4,293
Other, net	(11)		49
Total revenue	144,888	174,181	292,175	366,819
Operating Expenses:
Brokerage, exchange and clearance fees, net	52,899	55,573	105,669	115,298
Communication and data processing	18,985	17,953	37,192	35,675
Employee compensation and payroll taxes	17,365	20,809	38,712	43,366
Interest and dividends expense	14,934	14,097	27,214	27,634
Operations and administrative	8,946	5,736	13,792	10,655
Depreciation and amortization	6,798	7,800	13,555	15,527
Amortization of purchased intangibles and acquired capitalized software	53	53	106	106
Debt issue costs related to debt refinancing	4,482		4,482
Transaction advisory fees and expenses	8,511	155	8,643	155
Reserve for legal matter	(2,176)		(2,176)
Charges related to share-based compensation at IPO	179	516	364	1,111
Financing interest expense on long-term borrowings	8,720	7,075	15,548	14,176
Total operating expenses	139,696	129,767	263,101	263,703
Income before income taxes and noncontrolling interest	5,192	44,414	29,074	103,116
Provision for income taxes	779	5,128	3,587	12,474
Net income	4,413	39,286	25,487	90,642
Noncontrolling interest	(3,512)	(30,908)	(20,006)	(71,916)
Net income available for common stockholders	$ 901	$ 8,378	$ 5,481	$ 18,726
Earnings per share
Basic (in dollars per share)	$ 0.01	$ 0.21	$ 0.11	$ 0.48
Diluted (in dollars per share)	$ 0.01	$ 0.21	$ 0.11	$ 0.48
Weighted average common shares outstanding
Basic (in shares)	40,814,214	38,230,684	40,607,791	38,220,390
Diluted (in shares)	40,814,214	38,230,684	40,607,791	38,220,390
Comprehensive income
Net income	$ 4,413	$ 39,286	$ 25,487	$ 90,642
Other comprehensive income (loss)
Foreign currency translation adjustment, net of taxes	4,852	(1,230)	5,637	1,264
Comprehensive income	9,265	38,056	31,124	91,906
Less: Comprehensive income attributable to non-controlling interests	(6,901)	(30,024)	(23,945)	(72,825)
Comprehensive income attributable to common stockholders	$ 2,364	$ 8,032	$ 7,179	$ 19,081