Note 2 - Summary of Significant Accounting Policies (Details) - Computation of Basic and Diluted Earnings Per Share (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Numerator:
Net income	$ 215,865	[1]	$ 188,715	[1]	$ 531,421
Less: Net income allocated to preferred shareholder	(51,650)		(57,386)		(224,408)
Less: Net income allocated to unvested restricted stock	(297)		(265)		(410)
Net income available to common stockholders for basic earnings per common share	163,918		131,064		306,603
Effect of dilutive securities:
Net income allocated to preferred shareholder	51,650		57,386		224,408
Interest on 1.25% convertible senior notes due 2032	899		899		268
Net income available to common and preferred stock for diluted earnings per share	$ 216,467		$ 189,349		$ 531,279
Denominator:
Weighted average basic common shares outstanding (in Shares)	278,687,740		253,118,247		201,953,799
Weighted average additional common shares outstanding if preferred shares converted to common shares (if dilutive) (in Shares)	87,812,786		110,826,557		147,812,786
Total weighted average common shares outstanding if preferred shares converted to common shares (in Shares)	366,500,526		363,944,804		349,766,585
Effect of dilutive securities:
Share-based awards (in Shares)	6,284,822		6,742,856		5,988,625
1.25% convertible senior notes due 2032 (in Shares)	31,312,850		31,312,850		12,576,473
Weighted average diluted shares outstanding (in Shares)	404,098,198		402,000,510		368,331,683
Income per share:
Basic (in Dollars per share)	$ 0.59	[1]	$ 0.52	[1]	$ 1.52
Diluted (in Dollars per share)	$ 0.54	[1]	$ 0.47	[1]	$ 1.44

[1] Per share amounts do not add across due to rounding differences in quarterly amounts and due to the impact of differences between the quarterly and annual weighted average share calculations.