Quarterly report pursuant to Section 13 or 15(d)

Revenue from Contracts with Customers - Impact on Statement of Financial Condition (Details)

Revenue from Contracts with Customers - Impact on Statement of Financial Condition (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Jun. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	$ 204,847		$ 172,103	$ 88,852
Securities owned, at fair value	6,548		3,881
Receivables from clearing brokers	45,013		48,543
Receivables from other broker-dealers	2,520		2,822
Notes receivable from financial advisors, net	5,893		47,369
Other receivables, net	129,182		60,707
Fixed assets, net	26,307		23,621
Restricted cash	6,589		760
Intangible assets, net	72,296		103,611
Goodwill	124,210		124,210
Contract acquisition costs, net	76,972		0
Cash surrender value of life insurance	12,907		12,711
Other assets	34,606		31,687
Total assets	747,890		632,025	$ 538,288
Securities sold, but not yet purchased, at fair value	4,920		231
Accrued compensation	27,418		33,343
Commissions and fees payable	105,194		67,221
Accounts payable and accrued liabilities	54,169		40,478
Deferred rent	2,772		2,151
Deferred income taxes	6,558		2,968
Deferred compensation liability	19,999		18,161
Accrued interest	191		232
Notes payable	136,171		96,849
Total liabilities	357,392		261,634
Commitments and contingencies (Note 9)
Preferred stock	2		2
Common stock	20		20
Additional paid-in capital	501,348		520,135
Accumulated deficit	(110,904)		(149,778)
Total shareholders’ equity of the Company	390,466		370,379
Noncontrolling interest	32		12
Total shareholders' equity	390,498		370,391
Total liabilities and shareholders' equity	747,890		632,025
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract acquisition costs, net		$ 40,566
Balances without the adoption of ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	204,847
Securities owned, at fair value	6,548
Receivables from clearing brokers	45,013
Receivables from other broker-dealers	2,520
Notes receivable from financial advisors, net	58,579
Other receivables, net	68,414
Fixed assets, net	26,307
Restricted cash	6,589
Intangible assets, net	93,314
Goodwill	124,210
Contract acquisition costs, net	0
Cash surrender value of life insurance	12,907
Other assets	34,150
Total assets	683,398
Securities sold, but not yet purchased, at fair value	4,920
Accrued compensation	27,446
Commissions and fees payable	74,836
Accounts payable and accrued liabilities	53,996
Deferred rent	2,772
Deferred income taxes	2,363
Deferred compensation liability	19,999
Accrued interest	191
Notes payable	136,171
Total liabilities	322,694
Preferred stock	2
Common stock	20
Additional paid-in capital	501,348
Accumulated deficit	(140,687)
Total shareholders’ equity of the Company	360,683
Noncontrolling interest	21
Total shareholders' equity	360,704
Total liabilities and shareholders' equity	683,398
Effects of Change Higher/(Lower) \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents	0
Securities owned, at fair value	0
Receivables from clearing brokers	0
Receivables from other broker-dealers	0
Notes receivable from financial advisors, net	(52,686)
Other receivables, net	60,768
Fixed assets, net	0
Restricted cash	0
Intangible assets, net	(21,018)
Goodwill	0
Contract acquisition costs, net	76,972
Cash surrender value of life insurance	0
Other assets	456
Total assets	64,492
Securities sold, but not yet purchased, at fair value	0
Accrued compensation	(28)
Commissions and fees payable	30,358
Accounts payable and accrued liabilities	173
Deferred rent	0
Deferred income taxes	4,195
Deferred compensation liability	0
Accrued interest	0
Notes payable	0
Total liabilities	34,698
Preferred stock	0
Common stock	0
Additional paid-in capital	0
Accumulated deficit	29,783	24,109
Total shareholders’ equity of the Company	29,783
Noncontrolling interest	11
Total shareholders' equity	29,794
Total liabilities and shareholders' equity	$ 64,492
Adjusted
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents		172,103
Securities owned, at fair value		3,881
Receivables from clearing brokers		48,543
Receivables from other broker-dealers		2,822
Notes receivable from financial advisors, net		6,803
Other receivables, net		119,356
Fixed assets, net		23,621
Restricted cash		760
Intangible assets, net		79,966
Goodwill		124,210
Contract acquisition costs, net		61,340
Cash surrender value of life insurance		12,711
Other assets		31,712
Total assets		687,828
Securities sold, but not yet purchased, at fair value		231
Accrued compensation		33,233
Commissions and fees payable		96,616
Accounts payable and accrued liabilities		39,241
Deferred rent		2,151
Deferred income taxes		6,603
Deferred compensation liability		18,161
Accrued interest		232
Notes payable		96,849
Total liabilities		293,317
Commitments and contingencies (Note 9)
Preferred stock		2
Common stock		20
Additional paid-in capital		520,135
Accumulated deficit		(125,669)
Total shareholders’ equity of the Company		394,488
Noncontrolling interest		23
Total shareholders' equity		394,511
Total liabilities and shareholders' equity		$ 687,828
Investment Banking \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents			0
Securities owned, at fair value			0
Receivables from clearing brokers			0
Receivables from other broker-dealers			0
Notes receivable from financial advisors, net			0
Other receivables, net			(137)
Fixed assets, net			0
Restricted cash			0
Intangible assets, net			0
Goodwill			0
Contract acquisition costs, net			0
Cash surrender value of life insurance			0
Other assets			25
Total assets			(112)
Securities sold, but not yet purchased, at fair value			0
Accrued compensation			(110)
Commissions and fees payable			0
Accounts payable and accrued liabilities			(104)
Deferred rent			0
Deferred income taxes			28
Deferred compensation liability			0
Accrued interest			0
Notes payable			0
Total liabilities			(186)
Commitments and contingencies (Note 9)
Preferred stock			0
Common stock			0
Additional paid-in capital			0
Accumulated deficit			74
Total shareholders’ equity of the Company			74
Noncontrolling interest			0
Total shareholders' equity			74
Total liabilities and shareholders' equity			(112)
Insurance Renewals \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents			0
Securities owned, at fair value			0
Receivables from clearing brokers			0
Receivables from other broker-dealers			0
Notes receivable from financial advisors, net			0
Other receivables, net			58,786
Fixed assets, net			0
Restricted cash			0
Intangible assets, net			(23,645)
Goodwill			0
Contract acquisition costs, net			0
Cash surrender value of life insurance			0
Other assets			0
Total assets			35,141
Securities sold, but not yet purchased, at fair value			0
Accrued compensation			0
Commissions and fees payable			29,395
Accounts payable and accrued liabilities			0
Deferred rent			0
Deferred income taxes			1,489
Deferred compensation liability			0
Accrued interest			0
Notes payable			0
Total liabilities			30,884
Commitments and contingencies (Note 9)
Preferred stock			0
Common stock			0
Additional paid-in capital			0
Accumulated deficit			4,257
Total shareholders’ equity of the Company			4,257
Noncontrolling interest			0
Total shareholders' equity			4,257
Total liabilities and shareholders' equity			35,141
Costs to obtain or fulfill a contract \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cash and cash equivalents			0
Securities owned, at fair value			0
Receivables from clearing brokers			0
Receivables from other broker-dealers			0
Notes receivable from financial advisors, net			(40,566)
Other receivables, net			0
Fixed assets, net			0
Restricted cash			0
Intangible assets, net			0
Goodwill			0
Contract acquisition costs, net			61,340
Cash surrender value of life insurance			0
Other assets			0
Total assets			20,774
Securities sold, but not yet purchased, at fair value			0
Accrued compensation			0
Commissions and fees payable			0
Accounts payable and accrued liabilities			(1,133)
Deferred rent			0
Deferred income taxes			2,118
Deferred compensation liability			0
Accrued interest			0
Notes payable			0
Total liabilities			985
Commitments and contingencies (Note 9)
Preferred stock			0
Common stock			0
Additional paid-in capital			0
Accumulated deficit			19,778
Total shareholders’ equity of the Company			19,778
Noncontrolling interest			11
Total shareholders' equity			19,789
Total liabilities and shareholders' equity			$ 20,774