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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net Income	$ 229,135	$ 47,188	$ 436,296	$ 161,335
Preferred stock dividends	(931)	(931)	(2,792)	(2,792)
Preferred Stock Conversions Inducements	0	0	0	0
Net income (loss) applicable to common stock	$ 228,204	$ 46,257	$ 433,504	$ 158,543
Weighted Average Number Of Shares Outstanding Basic	102,714,262	102,451,410	102,666,570	102,363,099
Weighted Average Number Diluted Shares Outstanding Adjustment	303,181	33,550	348,104	182,375
Average common shares outstanding - assuming dilution	103,017,443	102,484,960	103,014,674	102,545,474
Earnings Per Share Basic	$ 2.22	$ 0.45	$ 4.22	$ 1.55
Earnings Per Share Diluted	$ 2.22	$ 0.45	$ 4.21	$ 1.55