Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net income	$ 23,000	$ 491	$ 2,898
Non-cash items included in net income:
Depreciation and amortization of furniture, equipment and leasehold improvements	5,657	6,788	7,188
Deferred Income Taxes and Tax Credits	(2,045)	(2,941)	4,538
Amortization of notes receivable	11,791	12,960	12,708
Amortization of debt issuance costs	353	484	485
Write-off of debt issuance costs	430	0	0
Amortization of mortgage servicing rights	0	1,286	727
(Reversal of) provision for credit losses	(25)	(1,751)	118
Share-based compensation	12,573	6,203	2,860
Excess Tax Benefit from Share-based Compensation, Operating Activities	0	(740)	(277)
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	0	(16,475)	0
Decrease (increase) in operating assets:
Cash and securities segregated for regulatory and other purposes	0	0	18,594
Deposits with clearing organizations	(4,037)	11,305	(12,980)
Receivable from brokers, dealers and clearing organizations	27,819	145,882	(46,438)
Increase (Decrease) in Accounts and Other Receivables	815	5,280	(23,716)
Income tax receivable	2,877	5,104	(6,697)
Securities purchased under agreements to resell	23,348	182,493	45,107
Securities owned	(219,489)	24,725	107,762
Notes receivable	(22,212)	(10,210)	(10,625)
Loans held for sale	0	60,234	(40,991)
Mortgage servicing rights	0	(1,300)	1,245
Other assets	(37,130)	2,368	35
Increase (decrease) in operating liabilities:
Drafts payable	3,184	(8,783)	12,638
Payable to brokers, dealers and clearing organizations	(9,906)	56,843	(92,615)
Payable to customers	(64,039)	(144,887)	(57,423)
Securities sold under agreements to repurchase	208,394	(273,361)	(35,995)
Securities sold but not yet purchased	9,436	(41,443)	33,983
Accrued compensation	21,184	(6,864)	(12,443)
Accounts payable and other liabilities	(6,484)	(69,996)	22,469
Cash used in operating activities	(16,136)	(66,865)	(19,413)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(5,611)	(5,731)	(5,889)
Proceeds from Divestiture of Businesses	0	45,448	0
Proceeds from Life Insurance Policy	1,744	0	0
Cash (used in) provided by investing activities	(3,867)	39,717	(5,889)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(5,836)	(5,887)	(6,008)
Payments of Ordinary Dividends, Noncontrolling Interest	(2,448)	(5,740)	0
Issuance of Class A non-voting common stock	26	0	0
Repurchase of Class A non-voting common stock for cancellation	(7,464)	(3,935)	(8,250)
Payments Related to Tax Withholding for Share-based Compensation	(2,237)	(1,341)	(1,683)
Proceeds from Issuance of Senior Long-term Debt	200,000	0	0
Redemption of senior secured notes	(150,000)	0	0
Payments of Debt Issuance Costs	(1,297)	0	0
Redemption of senior secured notes	(27,500)	45,600	40,800
Cash provided by financing activities	3,244	28,697	24,859
Net (decrease) increase in cash and cash equivalents	(16,759)	1,549	(443)
Cash and cash equivalents, beginning of year	64,913	63,364	63,807
Cash and cash equivalents, end of year	48,154	64,913	63,364
Schedule of non-cash financing activities
Employee share plan issuance	6,569	5,776	3,373
Supplemental disclosure of cash flow information
Cash paid during the year for interest	23,899	19,705	17,273
Proceeds from Income Tax Refunds	$ (2,378)	$ (5,009)
Cash (received) paid during the year for income taxes, net			$ 6,088