Stockholders' Equity - Additional Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Stockholders Equity Note Disclosure [Line Items]
Common stock, authorized capital (in shares)	60,000,000	60,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares outstanding (in shares)	30,219,278	29,871,354
Preferred stock, authorized capital (in shares)	5,000,000	5,000,000
Preferred stock, par value (in dollars per shares)	$ 0.01	$ 0.01
Preferred stock, shares outstanding (in shares)	0	0
Restricted Stock
Stockholders Equity Note Disclosure [Line Items]
Antidilutive stock options excluded from earning per share (in shares)	787,000	350,000