Earnings Per Share - Schedule of Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Net income (loss)		$ 5,096	$ 12,933	$ (183,498)	$ 29,463
Denominator for basic earnings per share - weighted average shares		36,673	36,512	36,659	36,552
Effect of dilutive securities: Employee stock options and restricted stock	[1]	200	398		345
Denominator for diluted earnings per share - Adjusted weighted average shares and the effect of dilutive securities		36,873	36,910	36,659	36,897
Net income (loss) per share - basic		$ 0.14	$ 0.35	$ (5.01)	$ 0.81
Net income (loss) per share - diluted	[2]	$ 0.14	$ 0.35	$ (5.01)	$ 0.80

[1] The effect of dilutive securities for employee stock options and restricted stock in the three and six months ended June 30, 2017 was affected by the adoption of ASU 2016-09 at the beginning of the year. In accordance with the standard, the effect of dilutive securities in the calculation of diluted net income per share was applied prospectively and results for the three and six months ended June 30, 2016 have not been revised.

[2] As a result of the net loss in the six months ended June 30, 2017, the effect of potentially dilutive securities would have been anti-dilutive and has been omitted from the calculation of diluted earnings per share.