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	$ 35,179	$ 47,226	$ 50,775
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	20,512	16,094	15,124
Bad debt expense	1,109	1,195	433
Loss (gain) on sale or disposition of assets and sublease, net	4,260	(171)	(3,650)
Loss on early extinguishment of debt		796	94
Equity in earnings of investees			(1,215)
Distributions received from equity investees			1,178
Equity-based compensation expense	2,900	2,330	1,453
Deferred income tax expense	46,494	3,473	2,531
Fair value adjustments to contingent consideration	180	100
Payments pursuant to tax receivable agreements	(13,371)	(1,344)
Non-cash change in tax receivable agreement liability	(32,736)
Other	1,145	1,029	1,014
Changes in operating assets and liabilities:
Accounts and notes receivable, current portion	(2,924)	(3,841)	(999)
Advances from/to affiliates	(106)	71	(771)
Other current and noncurrent assets	(2,414)	362	502
Other current and noncurrent liabilities	1,583	(2,616)	7,253
Income taxes receivable/payable	(1,133)	(71)	2,770
Deferred revenue and deposits, current portion	2,610	(254)	866
Net cash provided by operating activities	63,288	64,379	77,358
Cash flows from investing activities:
Purchases of property, equipment and software and capitalization of trademark costs	(2,198)	(4,502)	(3,628)
Acquisitions, net of cash acquired of $0, $131 and $0, respectively	(35,720)	(112,934)
Dispositions		200	5,650
Other investing activity, net		(96)	(358)
Net cash (used in) provided by investing activities	(37,918)	(117,332)	1,664
Cash flows from financing activities:
Proceeds from issuance of debt, net		233,825
Payments on debt	(2,366)	(203,298)	(9,722)
Capitalized debt amendment costs		(1,379)	(555)
Distributions paid to non-controlling unitholders	(17,260)	(17,927)	(42,827)
Dividends and dividend equivalents paid to Class A common stockholders	(12,793)	(10,578)	(24,003)
Proceeds from exercise of stock options		101	2,248
Payment of payroll taxes related to net settled restricted stock units	(816)	(516)	(327)
Net cash (used in) provided by financing activities	(33,235)	228	(75,186)
Effect of exchange rate changes on cash	1,063	122	(823)
Net (decrease) increase in cash and cash equivalents	(6,802)	(52,603)	3,013
Cash and cash equivalents, beginning of year	57,609	110,212	107,199
Cash and cash equivalents, end of period	50,807	57,609	110,212
Supplemental disclosures of cash flow information:
Cash paid for interest	9,972	7,797	9,319
Net cash paid for income taxes	10,078	11,912	5,841
Schedule of non-cash investing and financing activities:
Establishment of amounts payable under tax receivable agreements			33,018
Establishment of deferred tax assets			43,774
Note receivable received as consideration for sale of brokerage operations assets		150	851
Increase in accounts payable for capitalization of trademark costs and purchases of property, equipment and software	$ 295	150	$ 667
Contingent consideration issued in a business acquisition		$ 6,300