Earnings Per Share - Reconciliation of Numerators and Denominators of Basic and Diluted (Loss) Earnings Per Computations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Income from continuing operations and shares used in basic calculations	$ 227,621	$ 9,807	$ 138,316	$ 24,556
Income from continuing operations and shares used in diluted calculations	$ 227,621	$ 9,807	$ 138,316	$ 24,556
Shares used in basic calculations (in shares)	114,113	46,411	68,632	49,619
Effect of dilutive stock based awards (in shares)	660	0	223	0
(Loss) Income and shares used in diluted calculations (in shares)	114,773	46,411	68,855	49,619
Basic earnings per share from continuing operations (in dollars per share)	$ 1.99	$ 0.21	$ 2.02	$ 0.49
Diluted earnings per share from continuing operations (in dollars per share)	$ 1.98	$ 0.21	$ 2.01	$ 0.49