Note 7 - Stock-Based Compensation (Detail) - Exercise Price Range of Options (USD $)	12 Months Ended
	Dec. 31, 2012
Number of Options	1,528,590
Weighted average remaining contractual life (in years)	3 years 255 days
Weighted average exercise price (in Dollars per share)	$ 36.09
$26.31-30.69 [Member]
Number of Options	38,500
Weighted average remaining contractual life (in years)	219 days
Weighted average exercise price (in Dollars per share)	$ 26.86
$30.70 - $35.08 [Member]
Number of Options	335,048
Weighted average remaining contractual life (in years)	3 years 328 days
Weighted average exercise price (in Dollars per share)	$ 32.25
$35.09 - $39.46
Number of Options	1,115,866
Weighted average remaining contractual life (in years)	3 years 255 days
Weighted average exercise price (in Dollars per share)	$ 37.38
$39.47 - $43.85 [Member]
Number of Options	39,176
Weighted average remaining contractual life (in years)	3 years 328 days
Weighted average exercise price (in Dollars per share)	$ 41.25