CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Statement of Cash Flows [Abstract]
Payments for (Proceeds from) Tenant Allowance	$ 1,128	$ 0
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	15,070	22,418
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	732	606
Amortization of intangible assets	1,470	951
Unrealized gains on trading investments	(676)	484
Stock based compensation expense	12,164	12,560
Deferred income taxes	114	(1,923)
Excess tax benefits from stock based compensation	(165)	(1,432)
Net sales of investments - trading securities	23,147	22,679
Other Operating Activities, Cash Flow Statement	275	(3)
Change in operating assets and liabilities:
Accounts receivable	(2,711)	(5,332)
Other current assets	900	236
Accounts payable and accrued liabilities	(82)	537
Compensation and benefits payable	(6,758)	(2,052)
Income taxes payable	(4,637)	1,899
Other liabilities	154	(28)
Net cash provided by operating activities	38,997	51,600
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(1,680)	(704)
Payments to Acquire Businesses, Net of Cash Acquired	0	24,133
Net cash used in investing activities	(1,680)	(24,837)
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchases of treasury stock	(5,629)	0
Payment for Repurchases of Stock for Benefit Plan	(614)	(1,327)
Restricted stock returned for payment of taxes	(3,710)	(5,621)
Excess tax benefits from stock based compensation	165	1,432
Other Payments to Acquire Businesses	(5,562)
Cash dividends	(14,827)	(13,065)
Net cash used in financing activities	(30,177)	(18,581)
Effect of currency rate changes on cash	812	(2,430)
NET INCREASE IN CASH AND CASH EQUIVALENTS	7,952	5,752
Cash and cash equivalents, beginning of period	22,740	18,131
Cash and cash equivalents, end of period	30,692	23,883
Supplemental cash flow information:
Cash paid during the period for income taxes	12,632	11,664
Common stock issued for acquisition	3,734	5,292
DividendsAccrued	7,682	6,452
Capital Expenditures Incurred but Not yet Paid	$ 0	$ 0