Note 4 - Earnings Per Common Share (Details) - Components Used in Computation of Basic and Diluted Earnings Per Common Share (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net income	$ 31,605	$ 38,159
Less: Net income allocated to preferred shareholder	(7,662)	(9,147)
Less: Net income allocated to unvested restricted stock	(67)	(59)
Net income available to common stockholders for basic earnings per common share	23,876	28,953
Effect of dilutive securities:
Net income allocated to preferred shareholder	7,662	9,147
Net income available to common and preferred stock for diluted earnings per share	31,579	38,141
Denominator:
Weighted average basic common shares outstanding (in Shares)	273,635,605	277,948,342
Weighted average additional common shares outstanding if preferred shares converted to common shares (if dilutive) (in Shares)	87,812,786	87,812,786
Total weighted average common shares outstanding if preferred shares converted to common shares (in Shares)	361,448,391	365,761,128
Effect of dilutive securities:
Share-based awards (in Shares)	5,443,367	6,633,777
Weighted average diluted shares outstanding (in Shares)	398,204,608	403,707,755
Income per common share:
Basic (in Dollars per share)	$ 0.09	$ 0.10
Diluted (in Dollars per share)	$ 0.08	$ 0.09
1¼% Convertible Senior Notes Due August 2032 [Member]
Effect of dilutive securities:
Interest on 1¼% convertible senior notes due 2032, included in cost of sales	$ 41	$ 41
Effect of dilutive securities:
1¼% convertible senior notes due 2032 (in Shares)	31,312,850	31,312,850