Net Income Per Common Share (Detail) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net Income Per Common Share [Line Items]
Net income	$ 120,817	$ (218,229)	$ 820,712	$ 62,836
Less: Preferred stock dividends	4,267	4,625	8,534	9,250
Net income (loss) available (related) to common shareholders	116,550	(222,854)	812,178	53,586
Add: Preferred Series B dividends, if Series B shares are dilutive	618		1,237
Add: Interest on Convertible Senior Notes, if Notes are dilutive			12,000
Net income available to common shareholders, as adjusted	$ 117,168	$ (222,854)	$ 825,415	$ 53,586
Weighted average shares of common stock outstanding-basic	822,623,370	559,700,836	787,712,527	557,360,358
Add: Effect of dilutive stock options	490,000		432,000	58,000
Add: Series B Cumulative Convertible Preferred Stock, if dilutive	4,642,000		4,642,000
Add: Convertible Senior Notes, if dilutive			34,835,000
Weighted average shares of common stock outstanding-diluted	827,754,731	559,700,836	827,622,301	557,418,175