Computation of net income (loss) per common share ("EPS"), basic and diluted (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net Income	$ 86,409	$ (120,307)
Preferred stock dividends	(931)	(930)
Net income (loss) applicable to common stock	$ 85,478	$ (121,237)
Weighted Average Number Of Shares Outstanding Basic	102,799,752	102,664,608
Weighted Average Number Diluted Shares Outstanding Adjustment	398,350	348,596
Average common shares outstanding - assuming dilution	103,198,102	103,013,204
Earnings Per Share Basic	$ 0.83	$ (1.18)
Earnings Per Share Diluted	$ 0.83	$ (1.18)