Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Detail) (Restated [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Restated [Member]
Net income / (loss)	$ 60,184	$ (2,034)
Weighted average shares of common stock outstanding (used to calculate basic EPS)	72,885	71,208
Net effect of dilutive employee stock options based on the treasury stock method	217	147
Weighted average shares of common stock outstanding (used to calculate diluted EPS)	73,102	71,355
Net income / (loss) per common share-basic	$ 0.83	$ (0.03)
Net income / (loss) per common share-diluted	$ 0.82	$ (0.03)