Note 6 - Stockholders' Equity (Detail) - Stock Based Compensation Plan Expenses (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock Based Compensation Expense	$ 7,326	$ 4,182	$ 3,829	$ 3,315	$ 3,090	$ 3,374	$ 3,675	$ 2,987	$ 18,652	$ 13,136	$ 16,810
Non Employee [Member]
Stock Based Compensation Expense									17	13	(7)
Employee Stock Purchase Program [Member]
Stock Based Compensation Expense									632	538	609
Restricted Stock [Member]
Stock Based Compensation Expense									12,468	7,216	8,271
Stock Options [Member]
Stock Based Compensation Expense									$ 5,535	$ 5,369	$ 7,937