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, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net Income (Loss) Attributable to Parent	$ 47,188	$ 27,533	$ 161,335	$ 148,350
Preferred stock dividends	(931)	(931)	(2,792)	(2,792)
Preferred Stock Conversions Inducements	0	0	0	0
Net income (loss) applicable to common stock	46,257	26,602	158,543	145,558
Weighted Average Number Of Shares Outstanding Basic	102,451,410	102,166,004	102,363,099	102,147,450
Weighted Average Number Diluted Shares Outstanding Adjustment	33,550	0	182,375	104,270
Average common shares outstanding - assuming dilution	102,484,960	102,166,004	102,545,474	102,251,720
Basic and dilutive EPS	$ 0.45	$ 0.26	$ 1.55	$ 1.42
Retained Earnings Member
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net Income (Loss) Attributable to Parent			$ 161,335	$ 148,350