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				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net Income (Loss) Attributable to Parent	$ 65,739		$ 110,685		$ 114,147		$ 120,817
Preferred stock dividends	(930)		(931)		(1,861)		(1,861)
Preferred Stock Conversions Inducements	0		0		0		0
Net income (loss) applicable to common stock	64,809		109,754		112,286		118,956
Weighted Average Number Of Shares Outstanding Basic	102,295,113		102,122,591		102,318,459		102,138,020
Weighted Average Number Diluted Shares Outstanding Adjustment	115,505		67,023		161,071		116,300
Average common shares outstanding - assuming dilution	102,410,618	[1]	102,189,614	[1]	102,479,530	[1]	102,254,320	[1]
Basic and dilutive EPS	$ 0.63		$ 1.07		$ 1.10		$ 1.16
Retained Earnings Member
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net Income (Loss) Attributable to Parent					$ 114,147		$ 120,817

[1] Since the number of common shares outstanding increased as a result of the 1-for-10 reverse stock split effected on May 29, 2012, the computations of basic and diluted EPS have been adjusted retroactively for all periods presented to reflect that change in capital structure. Refer to Note ##SE for additional information on this transaction.