Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (1,387)	$ (19,712)	$ 12,161
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17,282	16,648	16,273
Impairment charge	40,035	32,097
Impairment loss on investment			1,320
Deferred income taxes	(6,225)	5,311	4,612
Non-cash interest	649	881	1,124
Amortization of syndication contracts	504	505	651
Payments on syndication contracts	(458)	(543)	(643)
Equity in net (income) loss of nonconsolidated affiliate		234	1,374
Non-cash stock-based compensation	5,125	4,377	5,787
(Gain) loss on disposal of property and equipment	(731)	158
(Gain) loss on debt extinguishment		255	550
Changes in assets and liabilities:
(Increase) decrease in trade receivables, net	(20,100)	8,610	5,895
(Increase) decrease in prepaid expenses and other current assets	11,526	2,102	(5,581)
Increase (decrease) in accounts payable, accrued expenses and other liabilities	17,229	(19,384)	(9,727)
Net cash provided by operating activities	63,449	31,539	33,796
Cash flows from investing activities:
Proceeds from sale of property and equipment and intangibles	5,089		33
Purchases of property and equipment	(9,060)	(25,283)	(17,006)
Purchases of intangibles	(158)	(2,300)	(3,153)
Purchase of a businesses, net of cash acquired	(21,261)		(3,522)
Purchases of marketable securities		(1,400)	(159,403)
Proceeds from marketable securities	63,480	43,647	25,000
Purchases of investments		(300)	(1,495)
Net cash provided by (used in) investing activities	38,090	14,364	(159,546)
Cash flows from financing activities:
Proceeds from stock option exercises			249
Tax payments related to shares withheld for share-based compensation plans	(1,426)	(1,688)	(2,268)
Payments on long-term debt	(3,000)	(28,000)	(53,000)
Dividends paid	(10,531)	(16,962)	(17,782)
Repurchase of Class A common stock	(525)	(12,565)	(13,812)
Payment of contingent consideration			(2,015)
Payments of capitalized debt offering and issuance costs		(225)
Net cash used in financing activities	(15,482)	(59,440)	(88,628)
Effect of exchange rates on cash, cash equivalents and restricted cash	(3)	(71)	(11)
Net increase (decrease) in cash, cash equivalents and restricted cash	86,054	(13,608)	(214,389)
Cash, cash equivalents and restricted cash:
Beginning	33,857	47,465	261,854
Ending	119,911	33,857	47,465
Cash payments for:
Interest	7,616	12,802	14,619
Income taxes	7,731	2,847	3,265
Supplemental disclosures of non-cash investing and financing activities:
Capital expenditures financed through accounts payable, accrued expenses and other liabilities	$ 1,155	730	660
Contingent consideration included in accounts payable, accrued expenses and other liabilities		$ 1,641	$ 8,119