Note 2 - Stock-Based Compensation (Details) - Stock Options (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Stock Options [Abstract]
Outstanding at January 1, 2014		1,356,446
Outstanding at January 1, 2014		$ 15.86
Outstanding at January 1, 2014	1 year 109 days	1 year 328 days
Outstanding at January 1, 2014		$ 25,505,753
Options exercised	(638,018)
Options exercised	$ 16.30
Options forfeited and expired	(8,397)
Options forfeited and expired	$ 11.22
Outstanding at September 30, 2014	710,031
Outstanding at September 30, 2014	$ 15.51
Outstanding at September 30, 2014	1 year 109 days	1 year 328 days
Outstanding at September 30, 2014	20,265,815
Options exercisable at September 30, 2014 and expected to vest	709,524
Options exercisable at September 30, 2014 and expected to vest	$ 15.52
Options exercisable at September 30, 2014 and expected to vest	1 year 109 days
Options exercisable at September 30, 2014 and expected to vest	20,245,815
Options exercisable at September 30, 2014	677,985
Options exercisable at September 30, 2014	$ 15.63
Options exercisable at September 30, 2014	1 year 73 days
Options exercisable at September 30, 2014	$ 19,268,944