Supplemental Guarantor Condensed Consolidated Financial Statements - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operations:
Cash provided by (used in) operating activities	$ 79,142	$ 168,570	$ (16,136)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(10,024)	(8,672)	(5,611)
Proceeds from Sale of Other Assets, Investing Activities			1,744
Payments to Acquire Intangible Assets	0	(400)	0
Proceeds from Life Insurance Policy	1,720	881	1,744
Cash used in by investing activities	(8,304)	(8,191)	(3,867)
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(5,944)	(5,833)	(5,836)
Payments of Ordinary Dividends, Noncontrolling Interest	0	(372)	(2,448)
Issuance of Class A non-voting common stock	83	70	26
Payments for Repurchase of Common Stock	(8,400)	(5,894)	(7,464)
Payment, Tax Withholding, Share-based Payment Arrangement	(1,014)	(2,529)	(2,237)
Proceeds from Issuance of Senior Long-term Debt	0	0	200,000
Repayments of Long-term Debt	(50,000)
Debt redemption costs	(1,688)	0	0
Redemption of senior secured notes	(50,000)	0	(150,000)
Debt Issuance Costs, Line of Credit Arrangements, Gross			(1,297)
Redemption of senior secured notes	(15,000)	(103,300)	(27,500)
Cash (used in) provided by financing activities	(81,963)	(117,858)	3,244
Net increase (decrease) in cash and cash equivalents	(11,125)	42,521	(16,759)
Cash and cash equivalents, beginning of year	90,675	48,154	64,913
Cash and cash equivalents, end of year	79,550	90,675	48,154
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 Sale of Other Assets, Investing Activities			0
Proceeds from Life Insurance Policy	0	0
Cash used in by 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
Issuance of Class A non-voting common stock	0	0
Payments for Repurchase of Common Stock	0	0
Payment, Tax Withholding, Share-based Payment Arrangement	0	0	0
Repayments of Long-term Debt	0
Debt redemption costs	0
Redemption of senior secured notes			0
Redemption of senior secured notes	0	0	0
Cash (used in) provided by 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
Parent
Cash flows from operations:
Cash provided by (used in) operating activities	18,248	60,270	(25,979)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0	0
Proceeds from Sale of Other Assets, Investing Activities			0
Cash used in by investing activities	0	0	0
Cash flows from financing activities
Cash dividends paid on Class A non-voting and Class B voting common stock	(5,944)	(5,833)	(5,836)
Payments of Ordinary Dividends, Noncontrolling Interest			0
Issuance of Class A non-voting common stock	83	70	26
Payments for Repurchase of Common Stock	(8,400)	(5,894)	(7,464)
Payment, Tax Withholding, Share-based Payment Arrangement	(1,014)	(2,529)	(2,237)
Proceeds from Issuance of Senior Long-term Debt			200,000
Repayments of Long-term Debt	(50,000)
Debt redemption costs	(1,688)
Redemption of senior secured notes			(150,000)
Debt Issuance Costs, Line of Credit Arrangements, Gross			(1,297)
Redemption of senior secured notes	0	0	0
Cash (used in) provided by financing activities	(66,963)	(14,186)	33,192
Net increase (decrease) in cash and cash equivalents	(48,715)	46,084	7,213
Cash and cash equivalents, beginning of year	53,526	7,442	229
Cash and cash equivalents, end of year	4,811	53,526	7,442
Guarantor Subsidiaries
Cash flows from operations:
Cash provided by (used in) operating activities	(1,647)	510	(6,568)
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	0	0	0
Proceeds from Sale of Other Assets, Investing Activities			0
Proceeds from Life Insurance Policy	0	0
Cash used in by investing activities	0	(400)	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	0
Issuance of Class A non-voting common stock	0	0	0
Payments for Repurchase of Common Stock	0	0	0
Payment, Tax Withholding, Share-based Payment Arrangement	0	0	0
Proceeds from Issuance of Senior Long-term Debt			0
Repayments of Long-term Debt	0
Debt redemption costs	0
Redemption of senior secured notes			0
Debt Issuance Costs, Line of Credit Arrangements, Gross			0
Redemption of senior secured notes	0	0	0
Cash (used in) provided by financing activities	0	0	0
Net increase (decrease) in cash and cash equivalents	(1,647)	110	(6,568)
Cash and cash equivalents, beginning of year	3,826	3,716	10,284
Cash and cash equivalents, end of year	2,179	3,826	3,716
Non-Guarantor Subsidiaries
Cash flows from operations:
Cash provided by (used in) operating activities	62,541	107,790	16,411
Cash flows from investing activities
Purchase of furniture, equipment and leasehold improvements	(10,024)	(8,672)	(5,611)
Proceeds from Sale of Other Assets, Investing Activities			1,744
Proceeds from Life Insurance Policy	1,720	881
Cash used in by investing activities	(8,304)	(7,791)	(3,867)
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		(372)	(2,448)
Issuance of Class A non-voting common stock	0	0	0
Payments for Repurchase of Common Stock	0	0	0
Payment, Tax Withholding, Share-based Payment Arrangement	0	0	0
Proceeds from Issuance of Senior Long-term Debt			0
Repayments of Long-term Debt	0
Debt redemption costs	0
Redemption of senior secured notes			0
Debt Issuance Costs, Line of Credit Arrangements, Gross			0
Redemption of senior secured notes	(15,000)	(103,300)	(27,500)
Cash (used in) provided by financing activities	(15,000)	(103,672)	(29,948)
Net increase (decrease) in cash and cash equivalents	39,237	(3,673)	(17,404)
Cash and cash equivalents, beginning of year	33,323	36,996	54,400
Cash and cash equivalents, end of year	72,560	33,323	36,996
Eliminations
Cash flows from financing activities
Payments of Ordinary Dividends, Noncontrolling Interest			0
Issuance of Class A non-voting common stock			0
Payments for Repurchase of Common Stock			0
Proceeds from Issuance of Senior Long-term Debt			0
Debt Issuance Costs, Line of Credit Arrangements, Gross			$ 0
Parent Company [Member]
Cash flows from investing activities
Proceeds from Life Insurance Policy	$ 0	0
Cash flows from financing activities
Payments of Ordinary Dividends, Noncontrolling Interest		$ 0