Net Income Per Common Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net Income Per Common Share:
Net income (loss)	$ (203,351)	$ 870,278
Less: Preferred stock dividends	17,992	17,992
Net income (loss) available to common shareholders, prior to adjustment for dilutive potential common shares, if necessary	(221,343)	852,286
Add: Interest on Convertible Senior Notes, if dilutive		10,450
Net income (loss) available to common shareholders, as adjusted	$ (221,343)	$ 862,736
Weighted average shares of common stock outstanding-basic	947,458,813	947,249,901
Add: Effect of dilutive stock options and Convertible Senior Notes, if dilutive		47,565,268
Weighted average shares of common stock outstanding-diluted	947,458,813	994,815,169
Net income (loss) per share available (related) to common share:
Basic	$ (0.23)	$ 0.90
Diluted	$ (0.23)	$ 0.87