Note 2 - Summary of Significant Accounting Policies (Detail) - Additional information regarding options outstanding (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Range of $14.19 to 14.19 [Member]
Low range of exercisable prices	$ 14.19
High range of exercisable prices	$ 14.19
Number outstanding, options outstanding (in Shares)	5
Weighted average contractual life, options outstanding	328 days
Weighted average exercise price, options outstanding	$ 14.19
Number exercisable, options exercisable (in Shares)	5
Weighted average exercise price, options exercisable	$ 14.19
Range of $20.00 - 24.95 [Member]
Low range of exercisable prices	$ 20.00
High range of exercisable prices	$ 24.95
Number outstanding, options outstanding (in Shares)	3
Weighted average contractual life, options outstanding	1 year 6 months
Weighted average exercise price, options outstanding	$ 21.00
Number exercisable, options exercisable (in Shares)	3
Weighted average exercise price, options exercisable	$ 21.00
Range of $25.00 - 29.95 [Member]
Low range of exercisable prices	$ 25.00
High range of exercisable prices	$ 29.95
Number outstanding, options outstanding (in Shares)	15
Weighted average contractual life, options outstanding	1 year 328 days
Weighted average exercise price, options outstanding	$ 27.24
Number exercisable, options exercisable (in Shares)	15
Weighted average exercise price, options exercisable	$ 27.24
Range of $30.00 - 34.99 [Member]
Low range of exercisable prices	$ 30.00
High range of exercisable prices	$ 34.99
Number outstanding, options outstanding (in Shares)	6
Weighted average contractual life, options outstanding	2 years 6 months
Weighted average exercise price, options outstanding	$ 34.14
Number exercisable, options exercisable (in Shares)	6
Weighted average exercise price, options exercisable	$ 34.14
Range of $35.00 - 39.95 [Member]
Low range of exercisable prices	$ 35.00
High range of exercisable prices	$ 39.95
Number outstanding, options outstanding (in Shares)	55
Weighted average contractual life, options outstanding	3 years
Weighted average exercise price, options outstanding	$ 37.49
Number exercisable, options exercisable (in Shares)	55
Weighted average exercise price, options exercisable	$ 37.49
Range of $40.00 - 42.97 [Member]
Low range of exercisable prices	$ 40.00
High range of exercisable prices	$ 42.97
Number outstanding, options outstanding (in Shares)	25
Weighted average contractual life, options outstanding	3 years 328 days
Weighted average exercise price, options outstanding	$ 42.97
Number exercisable, options exercisable (in Shares)	25
Weighted average exercise price, options exercisable	$ 42.97
Range of $14.19 - 42.97 [Member]
Low range of exercisable prices	$ 14.19
High range of exercisable prices	$ 42.97
Number outstanding, options outstanding (in Shares)	109
Weighted average contractual life, options outstanding	2 years 328 days
Weighted average exercise price, options outstanding	$ 35.71
Number exercisable, options exercisable (in Shares)	109
Weighted average exercise price, options exercisable	$ 35.71