Supplemental Guarantor Condensed Consolidated Financial Statements - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operations:
Cash provided by (used in) operating activities		$ (67,466)	$ (20,819)	$ 78,315
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements		(5,731)	(5,889)	(4,398)
Proceeds from Divestiture of Businesses		(45,448)	0	0
Cash provided by (used in) investing activities		39,717	(5,889)	(4,398)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock		(5,887)	(6,008)	(5,983)
Payments of Ordinary Dividends, Noncontrolling Interest	$ (5,700)	(5,740)	0	0
Payments for Repurchase of Common Stock		(3,935)	(8,250)	0
Issuance of Class A non-voting common stock		0	0	185
Excess tax benefit (deficiency) from share-based awards		(740)	(277)	1,194
Redemption of senior secured notes		0	0	(45,000)
Redemption of senior secured notes		45,600	40,800	(58,800)
Cash provided by (used in) financing activities		29,298	26,265	(108,404)
Net increase (decrease) in cash and cash equivalents		1,549	(443)	(34,487)
Cash and cash equivalents, beginning of year		63,364	63,807	98,294
Cash and cash equivalents, end of year		64,913	63,364	63,807
Eliminations
Cash flows from operations:
Cash provided by (used in) operating activities		0	0	0
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements		0	0	0
Proceeds from Divestiture of Businesses		0
Cash provided by (used in) investing activities		0	0	0
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock		0	0	0
Payments of Ordinary Dividends, Noncontrolling Interest		0
Payments for Repurchase of Common Stock		0	0
Issuance of Class A non-voting common stock				0
Excess tax benefit (deficiency) from share-based awards		0	0	0
Redemption of senior secured notes				0
Redemption of senior secured notes		0	0	0
Cash provided by (used in) financing activities		0	0	0
Net increase (decrease) in cash and cash equivalents		0	0	0
Cash and cash equivalents, beginning of year		0	0	0
Cash and cash equivalents, end of year		0	0	0
Guarantor Subsidiaries
Cash flows from operations:
Cash provided by (used in) operating activities		7,698	1,029	(29,344)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements		0	0	0
Proceeds from Divestiture of Businesses		0
Cash provided by (used in) investing activities		0	0	0
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock		0	0	0
Payments of Ordinary Dividends, Noncontrolling Interest		0
Payments for Repurchase of Common Stock		0	0
Issuance of Class A non-voting common stock				0
Excess tax benefit (deficiency) from share-based awards		0	0	0
Redemption of senior secured notes				0
Redemption of senior secured notes		0	0	0
Cash provided by (used in) financing activities		0	0	0
Net increase (decrease) in cash and cash equivalents		7,698	1,029	(29,344)
Cash and cash equivalents, beginning of year		2,586	1,557	30,901
Cash and cash equivalents, end of year		10,284	2,586	1,557
Non-Guarantor Subsidiaries
Cash flows from operations:
Cash provided by (used in) operating activities		(85,048)	(36,851)	58,064
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements		(5,731)	(5,889)	(4,398)
Proceeds from Divestiture of Businesses		(45,448)
Cash provided by (used in) investing activities		39,717	(5,889)	(4,398)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock		0	0	0
Payments of Ordinary Dividends, Noncontrolling Interest		(5,740)
Payments for Repurchase of Common Stock		0	0
Issuance of Class A non-voting common stock				0
Excess tax benefit (deficiency) from share-based awards		0	0	0
Redemption of senior secured notes				0
Redemption of senior secured notes		45,600	40,800	(58,800)
Cash provided by (used in) financing activities		39,860	40,800	(58,800)
Net increase (decrease) in cash and cash equivalents		(5,471)	(1,940)	(5,134)
Cash and cash equivalents, beginning of year		59,871	61,811	66,945
Cash and cash equivalents, end of year		54,400	59,871	61,811
Parent
Cash flows from operations:
Cash provided by (used in) operating activities		9,884	15,003	49,595
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements		0	0	0
Proceeds from Divestiture of Businesses		0
Cash provided by (used in) investing activities		0	0	0
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock		(5,887)	(6,008)	(5,983)
Payments of Ordinary Dividends, Noncontrolling Interest		0
Payments for Repurchase of Common Stock		(3,935)	(8,250)
Issuance of Class A non-voting common stock				185
Excess tax benefit (deficiency) from share-based awards		(740)	(277)	1,194
Redemption of senior secured notes				(45,000)
Redemption of senior secured notes		0	0	0
Cash provided by (used in) financing activities		(10,562)	(14,535)	(49,604)
Net increase (decrease) in cash and cash equivalents		(678)	468	(9)
Cash and cash equivalents, beginning of year		907	439	448
Cash and cash equivalents, end of year		$ 229	$ 907	$ 439