Components of Calculation of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss	$ (5,638)		$ (71,918)		$ (17,537)		$ (98,258)
Weighted-average shares, basic	46,030		45,768		45,988		45,724
Effect of dilutive securities	0	[1]	0	[1]	0	[1]	0	[1]
Weighted-average shares, diluted	46,030		45,768		45,988		45,724

[1] 1 For each of the three and six month periods ended June 30, 2012 and 2011, an amount less than 0.1 million of potentially dilutive securities, including the Convertible Notes, stock options, restricted stock and restricted stock units, had the effect of being anti-dilutive and were excluded from the calculation of diluted earnings per common share.