Earnings Per Share - Computation of Basic and Diluted Loss Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Numerator for basic and diluted earnings per share - net income	$ 15,471	$ 4,962	$ 129,137	$ 9,499
Denominator:
Denominator for basic earnings per share - weighted average shares	9,419	9,050	9,402	9,050
Effect of dilutive securities:
Restricted stock	140	8	138	8
Denominator for diluted earnings per share - weighted average shares	9,559	9,058	9,540	9,058
Basic income per common share	$ 1.64	$ 0.55	$ 13.74	$ 1.05
Diluted income per common share	$ 1.62	$ 0.55	$ 13.54	$ 1.05