Note 11 - Share Based Compensation and Employee Benefit Plans - Stock Option (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Balance of Outstanding Options at January 1, 2016 (in shares) | shares	3,475,115
Balance of Outstanding Options at January 1, 2016 (in dollars per share) | $ / shares	$ 20.95
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | shares	493,088
Granted (in dollars per share) | $ / shares	$ 17.65
Exercised (in shares) | shares	(466,877)
Exercised (in dollars per share) | $ / shares	$ 13.82
Forfeited (in shares) | shares	(11,500)
Forfeited (in dollars per share) | $ / shares	$ 25.55
Balance of Outstanding Options at December 31, 2016 (in shares) | shares	3,489,826
Balance of Outstanding Options at December 31, 2016 (in dollars per share) | $ / shares	$ 21.42
Balance of Outstanding Options at December 31, 2016 (Year)	5 years 313 days
Balance of Outstanding Options at December 31, 2016 | $	$ 36,573,365
Expected to vest after December 31, 2016 (in shares) | shares	1,823,896
Expected to vest after December 31, 2016 (in dollars per share) | $ / shares	$ 24.79
Expected to vest after December 31, 2016 (Year)	7 years 229 days
Expected to vest after December 31, 2016 | $	$ 12,969,933
Vested and exercisable at December 31, 2016 (in shares) | shares	1,608,248
Vested and exercisable at December 31, 2016 (in dollars per share) | $ / shares	$ 17.48
Vested and exercisable at December 31, 2016 (Year)	3 years 292 days
Vested and exercisable at December 31, 2016 | $	$ 23,198,547