Schedule of Reconciliation of Numerator and Denominator of Earning Per Common Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Earnings Per Share [Abstract]
Net (loss) income	$ (24,621)	$ 77,366		$ 24,214
Weighted average common shares outstanding	78,914,310	72,687,622		72,543,500
Weighted average potential dilutive common shares		3,948,795	[1],[2]	710,298	[1],[2]
Weighted average common shares outstanding-assuming dilution	78,914,310	76,636,417		73,253,798
Net (loss) income per common share-basic	$ (0.31)	$ 1.06		$ 0.33
Net (loss) income per common share-diluted	$ (0.31)	$ 1.01		$ 0.33

[1] Potential common shares consist of common stock issuable under the assumed exercise of stock options and restricted stock awards using the treasury stock method.

[2] For the year ended December 31, 2013, 2,325,209 potential common shares consisting of common stock under the assumed exercise of stock options and restricted stock awards using the treasury stock method were not included in the computation of the diluted net (loss) income per share since their inclusion would have an antidilutive effect.