Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 33,245,000	$ 38,829,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,678,000	11,482,000
Bad debt expense	836,000	1,177,000
Loss on sale or disposition of assets and sublease, net	(3,859,000)	(85,000)
Loss on early extinguishment of debt		136,000
Equity-based compensation expense	2,161,000	1,812,000
Deferred income tax expense	3,919,000	3,244,000
Fair value adjustments to contingent consideration	250,000
Payments pursuant to tax receivable agreements	(7,296,000)	(1,344,000)
Other	888,000	802,000
Changes in operating assets and liabilities	(100,000)	(7,183,000)
Net cash provided by operating activities	53,440,000	49,040,000
Cash flows from investing activities:
Purchases of property, equipment and software	(1,733,000)	(3,229,000)
Proceeds from sale of property and equipment		12,000
Capitalization of trademark costs	(48,000)	(35,000)
Acquisitions, net of cash acquired of $0 and $131, respectively		(17,869,000)
Other investing activity, net		54,000
Net cash used in investing activities	(1,781,000)	(21,067,000)
Cash flows from financing activities:
Payments on debt	(1,763,000)	(14,220,000)
Distributions paid to non-controlling unitholders	(14,213,000)	(14,094,000)
Dividends and dividend equivalents paid to Class A common stockholders	(9,607,000)	(7,932,000)
Payments on capital lease obligations	(9,000)	(72,000)
Proceeds from exercise of stock options		101,000
Payment of payroll taxes related to net settled restricted stock units	(816,000)	(360,000)
Net cash used in financing activities	(26,408,000)	(36,577,000)
Effect of exchange rate changes on cash	1,076,000	373,000
Net increase (decrease) in cash and cash equivalents	26,327,000	(8,231,000)
Cash and cash equivalents, beginning of year	57,609,000	110,212,000
Cash and cash equivalents, end of period	83,936,000	101,981,000
Supplemental disclosures of cash flow information:
Cash paid for interest	7,477,000	6,195,000
Net cash paid for income taxes	8,619,000	9,492,000
Schedule of non-cash investing and financing activities:
Note receivable received as consideration for sale of brokerage operations assets		150,000
Capital lease for property and equipment		33,000
Increase in accounts payable for capitalization of trademark costs and purchases of property, equipment and software	$ 310,000	89,000
Contingent consideration issued in a business acquisition		$ 6,300,000