Supplemental Guarantor Condensed Consolidated Financial Statements - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operations:
Cash provided by (used in) operating activities	$ (27,543)	$ (41,986)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(2,696)	(1,550)
Payments to Acquire Intangible Assets	(400)	0
Cash used in investing activities	(3,096)	(1,550)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(1,456)	(1,480)
Cash dividends paid to non-controlling interest	0	(816)
Payments for Repurchase of Common Stock	0	(4,357)
Payments for employee taxes withheld related to vested share-based awards	(2,444)	(2,203)
Redemption of senior secured notes	29,100	49,900
Cash provided by financing activities	25,200	41,044
Net decrease in cash and cash equivalents	(5,439)	(2,492)
Cash and cash equivalents, beginning of period	48,154	64,913
Cash and cash equivalents, end of period	42,715	62,421
Eliminations
Cash flows from operations:
Cash provided by (used in) operating activities	0	0
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0
Payments to Acquire Intangible Assets	0
Cash used in investing activities	0	0
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	0	0
Cash dividends paid to non-controlling interest		0
Payments for Repurchase of Common Stock		0
Payments for employee taxes withheld related to vested share-based awards	0	0
Redemption of senior secured notes	0	0
Cash provided by financing activities	0	0
Net decrease in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
Guarantor Subsidiaries
Cash flows from operations:
Cash provided by (used in) operating activities	919	4,100
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0
Payments to Acquire Intangible Assets	(400)
Cash used in investing activities	(400)	0
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	0	0
Cash dividends paid to non-controlling interest		0
Payments for Repurchase of Common Stock		0
Payments for employee taxes withheld related to vested share-based awards	0	0
Redemption of senior secured notes	0	0
Cash provided by financing activities	0	0
Net decrease in cash and cash equivalents	519	4,100
Cash and cash equivalents, beginning of period	3,716	10,284
Cash and cash equivalents, end of period	4,235	14,384
Non-Guarantor Subsidiaries
Cash flows from operations:
Cash provided by (used in) operating activities	(30,416)	(54,803)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(2,696)	(1,550)
Payments to Acquire Intangible Assets	0
Cash used in investing activities	(2,696)	(1,550)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	0	0
Cash dividends paid to non-controlling interest		(816)
Payments for Repurchase of Common Stock		0
Payments for employee taxes withheld related to vested share-based awards	0	0
Redemption of senior secured notes	29,100	49,900
Cash provided by financing activities	29,100	49,084
Net decrease in cash and cash equivalents	(4,012)	(7,269)
Cash and cash equivalents, beginning of period	36,996	54,400
Cash and cash equivalents, end of period	32,984	47,131
Parent
Cash flows from operations:
Cash provided by (used in) operating activities	1,954	8,717
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0
Payments to Acquire Intangible Assets	0
Cash used in investing activities	0	0
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(1,456)	(1,480)
Cash dividends paid to non-controlling interest		0
Payments for Repurchase of Common Stock		(4,357)
Payments for employee taxes withheld related to vested share-based awards	(2,444)	(2,203)
Redemption of senior secured notes	0	0
Cash provided by financing activities	(3,900)	(8,040)
Net decrease in cash and cash equivalents	(1,946)	677
Cash and cash equivalents, beginning of period	7,442	229
Cash and cash equivalents, end of period	$ 5,496	$ 906