Note 8 - Stockholders' Equity (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended		12 Months Ended			17 Months Ended
	Dec. 31, 2012	Nov. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Common Class A [Member]	Jul. 31, 2012 Common Class A [Member]	Aug. 31, 2011 Common Class A [Member]	Jun. 30, 2000 Common Class A [Member]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased							1,000,000	2,000,000	1,000,000
Treasury Stock, Shares, Acquired						1,145,147
Treasury Stock Acquired, Average Cost Per Share (in Dollars per share)			$ 24.41	$ 17.29	$ 7.88	$ 22.33
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased						1,854,853
Shares Paid for Tax Withholding for Share Based Compensation			80,687	56,012	61,153
Payments of Dividends (in Dollars)	$ 2,600	$ 2,500	$ 12,066	$ 6,822	$ 3,919