Note 6 - Stockholders' Equity (Detail) (USD $)	0 Months Ended	1 Months Ended		0 Months Ended	1 Months Ended	3 Months Ended	9 Months Ended	11 Months Ended	12 Months Ended										1 Months Ended			12 Months Ended		1 Months Ended					12 Months Ended												0 Months Ended	12 Months Ended
	Dec. 11, 2012	Dec. 28, 2012	Apr. 24, 2012	Feb. 14, 2012	Feb. 28, 2011	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Restricted Stock [Member] Minimum [Member]	Dec. 31, 2012 Restricted Stock [Member] Maximum [Member]	Dec. 31, 2012 Restricted Stock [Member]	Dec. 31, 2011 Restricted Stock [Member]	Dec. 31, 2010 Restricted Stock [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2012 Performance Based Restricted Stock Unit [Member] Met [Member]	Dec. 28, 2012 Performance Based Restricted Stock Unit [Member]	Apr. 24, 2012 Performance Based Restricted Stock Unit [Member]	Feb. 25, 2010 Performance Based Restricted Stock Unit [Member]	Dec. 31, 2012 Stock Option Modification [Member]	Dec. 31, 2012 RSUs And PSUs [Member]	Apr. 24, 2012 Time Base Restricted Unit [Member]	Feb. 28, 2011 Time Base Restricted Unit [Member]	Feb. 28, 2011 CEO [Member]	Feb. 28, 2011 Executive Restricted Stock Unit [Member]	Apr. 24, 2012 Nonexecutive Restrcted Stock Unit [Member]	Dec. 31, 2012 Highest [Member]	Dec. 31, 2012 Common Class A [Member] Two Thousand Four Equity Incentive Plan [Member]	Dec. 31, 1998 Nineteen Ninety Eight Stock Option Plan [Member]	Dec. 31, 2012 Two Thousand Four Equity Incentive Plan [Member]	Dec. 31, 2011 Two Thousand Four Equity Incentive Plan [Member]	Dec. 31, 2010 Two Thousand Four Equity Incentive Plan [Member]	Dec. 31, 2010 Two Thousand Four Equity Incentive Plan [Member]	Dec. 31, 2012 Two Thousand Four Employee Stock Purchase Plan [Member]	Dec. 31, 2011 Two Thousand Four Employee Stock Purchase Plan [Member]	Dec. 31, 2010 Two Thousand Four Employee Stock Purchase Plan [Member]	Dec. 31, 2012 Prior To July 13, 2006 [Member]	Dec. 31, 2012 After July 13, 2006 [Member]	Dec. 11, 2012 Two Thousand Four Equity Incentive Plan [Member]	Dec. 31, 2012 Two Thousand Four Equity Incentive Plan [Member]	Dec. 31, 2012 Two Thousand Four Employee Stock Purchase Plan [Member]
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense									$ 200,000	$ 100,000						$ 300,000
Common Stock, Dividends, Per Share, Declared (in Dollars per share)	$ 1.00
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	1.0471																														ten
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in Shares)		73,805																	26,851																						171,484
Allocated Share-based Compensation Expense	2,900,000	500,000				2,800,000			18,652,000	13,126,000	16,810,000								1,500,000										9,100,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options						100,000			100,000																							1,600,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term												1 year 328 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate													41.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate									0.30%
Share-based Compensation Arrangement by Share-based Payment Award, Description				50%													On December 28, 2012, the Company's Board of Directors approved the RSU Modification of unvested RSUs whereby for each unvested RSU or performance-based RSU ("PSU") as of December 28, 2012, the holder will receive 1.0471 shares upon vesting of the original awards granted.													The 2004 Plan provides for annual increases in the number of shares available for issuance beginning on January1, 2005 equal to the least of: 5% of the outstanding shares of common stock on the first day of the year, 2,400,000 shares, or a number of shares determined by the Board of Directors.	the rate of 25percent one year from the date of grant and 1/48thmonthly thereafter											four	The Purchase Plan provides for an automatic annual increase beginning on January 1, 2005 by an amount equal to the least of 1,000,000 shares; 2% of the outstanding shares of common stock on the first day of the year; or a number of shares as determined by the Board of Directors.
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)																															11,807,024											800,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			2 years	2 years	2 years																										4 years								10 years	7 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)						4,957,244			4,957,244	4,291,737																					1,392,750
Stock Issued During Period, Shares, New Issues (in Shares)																		356,752
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)				413,000				370,500	178,484	152,500										125,333	416,000	171,484	73,805	219,317	153,000			344,650				(1,152,320)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value																																10,000,000	5,800,000	17,400,000
Proceeds from Stock Options Exercised																																13,400,000	4,700,000		14,300,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition									36 days																							1 year 328 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Intrinsic Value (in Dollars per share)														$ 10,500,000	$ 5,800,000	$ 4,500,000
Share Based Compensation Arrangement By Share Based Payment Award Restricted Units Outstanding Intrinsic Value						36,300,000		15,900,000	36,300,000	19,600,000	15,900,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Share-based Awards Other than Options														19,200,000
														2 years 73 days
Share Based Compensation Share Based Payment Other Than Options Percentage Allowed			300.00%																							100.00%	300.00%
Performance Level RSU Reduction Percentage					15.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee (in Shares)							2,000
Share Based Compensation Arrangement By Share Based Payment Award Maximum Amount Per Employee							$25,000
Employee Stock Ownership Plan (ESOP), Shares in ESOP (in Shares)							200,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in Shares)									151,770	149,981	114,387
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value																																				1,000,000	300,000	300,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized						100,000			100,000
Proceeds from Stock Plans									$ 1,852,000	$ 1,773,000	$ 1,885,000