Earnings Per Share (Calculation of Basic and Diluted Earnings Per Share) (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]
Net income (loss) available to common shareholders	$ (31,375)	$ (22,214)	$ (61,520)	$ 41,768
Weighted average common shares outstanding used to compute basic EPS	35,670	34,998	35,490	34,747
Dilutive effect of stock based awards	0	0	0	253
Weighted average common shares outstanding used to compute diluted EPS	35,670	34,998	35,490	35,000
Basic EPS	$ (0.88)	$ (0.63)	$ (1.73)	$ 1.20
Diluted EPS	$ (0.88)	$ (0.63)	$ (1.73)	$ 1.19