Supplemental Guarantor Condensed Consolidated Financial Statements - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operations:
Cash used in operating activities	$ (37,991)	$ 11,311
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(6,941)	(3,947)
Cash used in investing activities	(6,246)	(4,347)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(2,865)	(2,913)
Payments for Repurchase of Common Stock	(6,352)	0
Payments for employee taxes withheld related to vested share-based awards	(1,014)	(2,444)
Redemption of senior secured notes	35,100	(10,800)
Cash provided by (used in) financing activities	24,869	(16,157)
Net decrease in cash and cash equivalents	(19,368)	(9,193)
Cash and cash equivalents, beginning of period	90,675	48,154
Cash and cash equivalents, end of period	71,307	38,961
Payments to Acquire Intangible Assets	0	400
Proceeds from Insurance Settlement, Investing Activities	695	0
Eliminations
Cash flows from operations:
Cash used in operating activities	0	0
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	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
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 (used in) 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
Payments to Acquire Intangible Assets	0	0
Proceeds from Insurance Settlement, Investing Activities	0
Guarantor Subsidiaries
Cash flows from operations:
Cash used in operating activities	(3,351)	1,272
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0
Cash used in investing activities	0	(400)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	0	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 (used in) financing activities	0	0
Net decrease in cash and cash equivalents	(3,351)	872
Cash and cash equivalents, beginning of period	3,826	3,716
Cash and cash equivalents, end of period	475	4,588
Payments to Acquire Intangible Assets	0	400
Proceeds from Insurance Settlement, Investing Activities	0
Non-Guarantor Subsidiaries
Cash flows from operations:
Cash used in operating activities	(29,580)	11,456
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(6,941)	(3,947)
Cash used in investing activities	(6,246)	(3,947)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	0	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	35,100	(10,800)
Cash provided by (used in) financing activities	35,100	(10,800)
Net decrease in cash and cash equivalents	(726)	(3,291)
Cash and cash equivalents, beginning of period	33,323	36,996
Cash and cash equivalents, end of period	32,597	33,705
Payments to Acquire Intangible Assets	0	0
Proceeds from Insurance Settlement, Investing Activities	695
Parent
Cash flows from operations:
Cash used in operating activities	(5,060)	(1,417)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	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	(2,865)	(2,913)
Payments for Repurchase of Common Stock	(6,352)
Payments for employee taxes withheld related to vested share-based awards	(1,014)	(2,444)
Redemption of senior secured notes	0	0
Cash provided by (used in) financing activities	(10,231)	(5,357)
Net decrease in cash and cash equivalents	(15,291)	(6,774)
Cash and cash equivalents, beginning of period	53,526	7,442
Cash and cash equivalents, end of period	38,235	668
Payments to Acquire Intangible Assets	0	$ 0
Proceeds from Insurance Settlement, Investing Activities	$ 0