Condensed Consolidating Financial Information - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	$ (70,385)	$ (40,121)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(2,075)	(2,572)
Proceeds from sale of assets	0	43,252
Proceeds from the settlement of company-owned life insurance	1,194	0
Cash provided by (used in) investing activities	(881)	40,680
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(2,940)	(2,947)
Dividends paid to noncontrolling interest	(816)	0
Repurchase of Class A non-voting common stock for cancellation	(5,159)	(3,798)
Issuance of senior secured note	200,000	0
Repayments of Long-term Debt	150,000	0
Payments for employee taxes withheld related to vested share-based awards	(2,203)	(1,341)
Debt issuance costs	(547)	0
Other financing activities	84,600	51,700
Cash flow provided by (used in) financing activities	122,935	43,614
Net increase (decrease) in cash and cash equivalents	51,669	44,173
Cash and cash equivalents, beginning of period	64,913	63,364
Cash and cash equivalents, end of period	116,582	107,537
Class A Stock [Member]
Cash flows from financing activities
Repurchase of Class A non-voting common stock for cancellation	(5,159)	(3,798)
Parent Company [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	34,273	7,785
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	(2,940)	(2,947)
Dividends paid to noncontrolling interest	0
Issuance of senior secured note	200,000
Repayments of Long-term Debt	150,000
Payments for employee taxes withheld related to vested share-based awards	(2,203)	(1,341)
Debt issuance costs	(547)
Other financing activities	0	0
Cash flow provided by (used in) financing activities	39,151	(8,086)
Net increase (decrease) in cash and cash equivalents	73,424	(301)
Cash and cash equivalents, beginning of period	229	907
Cash and cash equivalents, end of period	73,653	606
Parent Company [Member] | Class A Stock [Member]
Cash flows from financing activities
Repurchase of Class A non-voting common stock for cancellation	(5,159)	(3,798)
Guarantor Subsidiaries [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Cash provided by (used in) operating activities	(7,052)	(2,061)
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
Issuance of senior secured note	0
Repayments of Long-term Debt	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	(7,052)	(2,061)
Cash and cash equivalents, beginning of period	10,284	2,586
Cash and cash equivalents, end of period	3,232	525
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	(97,606)	(45,845)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(2,075)	(2,572)
Proceeds from sale of assets		43,252
Proceeds from the settlement of company-owned life insurance	1,194
Cash provided by (used in) investing activities	(881)	40,680
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	(816)
Issuance of senior secured note	0
Repayments of Long-term Debt	0
Payments for employee taxes withheld related to vested share-based awards	0	0
Debt issuance costs	0
Other financing activities	84,600	51,700
Cash flow provided by (used in) financing activities	83,784	51,700
Net increase (decrease) in cash and cash equivalents	(14,703)	46,535
Cash and cash equivalents, beginning of period	54,400	59,871
Cash and cash equivalents, end of period	39,697	106,406
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
Issuance of senior secured note	0
Repayments of Long-term Debt	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