CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total USD ($)	Class A Common Stock USD ($)	Class B Common Stock USD ($)	Common Stock USD ($)	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid In Capital USD ($)	Retained Earnings USD ($)	Retained Earnings Class A Common Stock USD ($)	Retained Earnings Class B Common Stock USD ($)	Accumulated Other Comprehensive Income USD ($)
Balance at Dec. 31, 2010	$ 371,376			$ 4,944			$ 129,327	$ 230,987			$ 6,118
Balance (in shares) at Dec. 31, 2010					18,628,000	2,307,000
Increase (Decrease) in Stockholders' Equity
Net income	94,149							94,149
Net change in accumulated other comprehensive income	(1,979)										(1,979)
Dividend declared Common Stock:
Dividend declared Common Stock		(11,280)	(1,266)						(11,280)	(1,266)
Stock options exercised, net of shares redeemed	438			7			881	(450)
Stock options exercised, net of shares redeemed (in shares)					38,000
Repurchase of Class A Common Stock	(492)			(4)			(147)	(341)
Repurchase of Class A Common Stock (in shares)					(23,000)
Conversion of Class B Common Stock to Class A Common Stock (in shares)					7,000	(7,000)
Net change in notes receivable on Common Stock	973						973
Deferred director compensation expense - Company Stock	171						171
Deferred director compensation expense - Company Stock (in shares)					2,000
Stock based compensation expense - options	277						277
Balance at Dec. 31, 2011	452,367			4,947			131,482	311,799			4,139
Balance (in shares) at Dec. 31, 2011					18,652,000	2,300,000
Increase (Decrease) in Stockholders' Equity
Net income	119,339							119,339
Net change in accumulated other comprehensive income	1,473										1,473
Dividend declared Common Stock:
Dividend declared Common Stock		(32,832)	(3,619)						(32,832)	(3,619)
Stock options exercised, net of shares redeemed	147			2			213	(68)
Stock options exercised, net of shares redeemed (in shares)					8,000
Repurchase of Class A Common Stock	(1,668)			(17)			(504)	(1,147)
Repurchase of Class A Common Stock (in shares)					(80,000)
Conversion of Class B Common Stock to Class A Common Stock (in shares)					29,000	(29,000)
Net change in notes receivable on Common Stock	426						426
Deferred director compensation expense - Company Stock	227						227
Deferred director compensation expense - Company Stock (in shares)					3,000
Stock based compensation expense - restricted stock	50						50
Stock based compensation expense - restricted stock (in shares)					82,000
Stock based compensation expense - options	792						792
Balance at Dec. 31, 2012	536,702			4,932			132,686	393,472			5,612
Balance (in shares) at Dec. 31, 2012					18,694,000	2,271,000
Increase (Decrease) in Stockholders' Equity
Net income	25,423							25,423
Net change in accumulated other comprehensive income	(2,491)										(2,491)
Dividend declared Common Stock:
Dividend declared Common Stock		(12,707)	(1,424)						(12,707)	(1,424)
Stock options exercised, net of shares redeemed	439			5			610	(176)
Stock options exercised, net of shares redeemed (in shares)					24,000
Repurchase of Class A Common Stock	(4,095)			(43)			(1,230)	(2,822)
Repurchase of Class A Common Stock (in shares)					(193,000)
Conversion of Class B Common Stock to Class A Common Stock (in shares)					11,000	(11,000)
Net change in notes receivable on Common Stock	250						250
Deferred director compensation expense - Company Stock	193						193
Deferred director compensation expense - Company Stock (in shares)					5,000
Stock based compensation expense - restricted stock	298						298
Stock based compensation expense - options	205						205
Balance at Dec. 31, 2013	$ 542,793			$ 4,894			$ 133,012	$ 401,766			$ 3,121
Balance (in shares) at Dec. 31, 2013					18,541,000	2,260,000