Significant Accounting Policies - Shares Used in Computation of Basic and Diluted Per Share Information (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Weighted average shares outstanding:
Weighted average number of shares outstanding for basic per share calculation	17,728,567	17,566,097	17,686,134	17,525,937
Effect of dilutive potential shares:
Options	0	1,379	0	1,715
Nonvested stock	235,820	117,671	225,589	121,968
Adjusted weighted average shares for diluted per share calculation	17,964,387	17,685,147	17,911,723	17,649,620
Anti-dilutive shares	0	30,001	149,100	211,101