Condensed Consolidating Financial Information - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	$ (34,386)	$ (23,955)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(3,506)	(4,397)
Proceeds from sale of assets	0	47,562
Proceeds from the settlement of company-owned life insurance	1,194	0
Cash provided by (used in) investing activities	(2,312)	43,165
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(4,394)	(4,417)
Dividends paid to noncontrolling interest	(2,448)	(5,740)
Repurchase of Class A non-voting common stock for cancellation	(7,464)	(3,832)
Issuance of senior secured notes	200,000	0
Redemption of senior secured notes	150,000	0
Payments for employee taxes withheld related to vested share-based awards	(2,232)	(1,341)
Debt issuance costs	(1,183)	0
Other financing activities	(15,700)	31,800
Cash flow provided by (used in) financing activities	16,579	16,470
Net increase (decrease) in cash and cash equivalents	(20,119)	35,680
Cash and cash equivalents, beginning of period	64,913	63,364
Cash and cash equivalents, end of period	44,794	99,044
Class A Stock [Member]
Cash flows from financing activities
Repurchase of Class A non-voting common stock for cancellation	(7,464)	(3,832)
Parent Company [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	(34,449)	8,985
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0
Proceeds from sale of assets		0
Proceeds from the settlement of company-owned life insurance	0
Cash provided by (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	(4,394)	(4,417)
Dividends paid to noncontrolling interest	0	0
Issuance of senior secured notes	200,000
Redemption of senior secured notes	150,000
Payments for employee taxes withheld related to vested share-based awards	(2,232)	(1,341)
Debt issuance costs	(1,183)
Other financing activities	0	0
Cash flow provided by (used in) financing activities	34,727	(9,590)
Net increase (decrease) in cash and cash equivalents	278	(605)
Cash and cash equivalents, beginning of period	229	907
Cash and cash equivalents, end of period	507	302
Parent Company [Member] | Class A Stock [Member]
Cash flows from financing activities
Repurchase of Class A non-voting common stock for cancellation	(7,464)	(3,832)
Guarantor Subsidiaries [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	1,679	27,793
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0
Proceeds from sale of assets		0
Proceeds from the settlement of company-owned life insurance	0
Cash provided by (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
Dividends paid to noncontrolling interest	0	0
Issuance of senior secured notes	0
Redemption of senior secured notes	0
Payments for employee taxes withheld related to vested share-based awards	0	0
Debt issuance costs	0
Other financing activities	0	0
Cash flow provided by (used in) financing activities	0	0
Net increase (decrease) in cash and cash equivalents	1,679	27,793
Cash and cash equivalents, beginning of period	10,284	2,586
Cash and cash equivalents, end of period	11,963	30,379
Guarantor Subsidiaries [Member] | Class A Stock [Member]
Cash flows from financing activities
Repurchase of Class A non-voting common stock for cancellation	0	0
Non-Guarantor Subsidiaries [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	(1,616)	(60,733)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(3,506)	(4,397)
Proceeds from sale of assets		47,562
Proceeds from the settlement of company-owned life insurance	1,194
Cash provided by (used in) investing activities	(2,312)	43,165
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock		0
Dividends paid to noncontrolling interest	(2,448)	(5,740)
Issuance of senior secured notes	0
Redemption of senior secured notes	0
Payments for employee taxes withheld related to vested share-based awards	0	0
Debt issuance costs	0
Other financing activities	(15,700)	31,800
Cash flow provided by (used in) financing activities	(18,148)	26,060
Net increase (decrease) in cash and cash equivalents	(22,076)	8,492
Cash and cash equivalents, beginning of period	54,400	59,871
Cash and cash equivalents, end of period	32,324	68,363
Non-Guarantor Subsidiaries [Member] | Class A Stock [Member]
Cash flows from financing activities
Repurchase of Class A non-voting common stock for cancellation	0	0
Consolidation, Eliminations [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	0	0
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0
Proceeds from sale of assets		0
Proceeds from the settlement of company-owned life insurance	0
Cash provided by (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
Dividends paid to noncontrolling interest	0	0
Issuance of senior secured notes	0
Redemption of senior secured notes	0
Payments for employee taxes withheld related to vested share-based awards	0	0
Debt issuance costs	0
Other financing activities	0	0
Cash flow provided by (used in) financing activities	0	0
Net increase (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
Consolidation, Eliminations [Member] | Class A Stock [Member]
Cash flows from financing activities
Repurchase of Class A non-voting common stock for cancellation	$ 0	$ 0