Quarterly report pursuant to Section 13 or 15(d)

Notes Payable - Narrative (Details)

Notes Payable - Narrative (Details) - USD ($)							1 Months Ended				3 Months Ended		9 Months Ended
Notes Payable - Narrative (Details) - USD ($)	Aug. 09, 2018	Jun. 22, 2018	May 22, 2018	Dec. 12, 2017	Nov. 21, 2017	Apr. 21, 2017	Jul. 31, 2018	Jun. 30, 2018	May 31, 2018	Feb. 28, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Aug. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Notes payable, debt issuance costs											$ 7,191,000		$ 7,191,000			$ 3,412,000
Commissions											$ 172,108,000	$ 131,467,000	$ 515,775,000	$ 394,492,000
Extinguishment of debt							$ 14,978,000
Amended and Restated Loan Agreement \| Securities America \| Term Loan
Line of Credit Facility [Line Items]
Face amount of debt						$ 8,000,000
Interest rate						5.75%
6.5% Senior notes \| Senior Notes
Line of Credit Facility [Line Items]
Face amount of debt				$ 76,569,000	$ 72,500,000
Interest rate					6.50%						6.50%		6.50%
Redemption percentage					100.00%
Option to exercise amount				4,069,000
Notes payable, debt issuance costs				3,313,000
Commissions				$ 1,187,000
Debt sold										$ 25,000,000			$ 6,240,000
Commissions receivable, percentage					2.00%
7% Senior Notes \| Senior Notes
Line of Credit Facility [Line Items]
Face amount of debt		$ 41,412,000	$ 40,000,000
Interest rate			7.00%								7.00%		7.00%
Redemption percentage			100.00%
Option to exercise amount		1,412,000
Notes payable, debt issuance costs		1,656,000
Commissions		$ 527,000
Debt sold								$ 25,000,000					$ 2,729,000
Commissions receivable, percentage			2.00%
7.25% Senior Notes \| Senior Notes
Line of Credit Facility [Line Items]
Face amount of debt	$ 60,000,000
Interest rate	7.25%										7.25%		7.25%
Redemption percentage	100.00%
Notes payable, debt issuance costs	$ 1,890,000
Commissions	100,000
Proceeds from issuance of debt	$ 60,000,000
Notes payable to Kestler Financial Group's former shareholders \| Notes Payable \| Kestler Financial Group
Line of Credit Facility [Line Items]
Face amount of debt															$ 5,450,000
Interest rate															4.00%
Interest expense on note											$ 18,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Availability under revolving credit facility											40,000,000		$ 40,000,000
Face amount of debt											40,000,000		40,000,000
Revolving Credit Facility \| Amended and Restated Loan Agreement \| Securities America \| Line of Credit
Line of Credit Facility [Line Items]
Availability under revolving credit facility											1,000,000		1,000,000
Basis spread on variable rate						2.25%
NFS Forgivable Loan
Line of Credit Facility [Line Items]
Term									6 years
Forgiveness, principal									$ 2,222,000
Fair Value \| Level 2
Line of Credit Facility [Line Items]
Notes payable, net											$ 194,131,000		$ 194,131,000			$ 99,129,000