Summary of Stock Options Activity and Related Information (Detail)	6 Months Ended
	Jun. 30, 2015 $ / shares shares
Options
Beginning balance | shares	141,077
Exercised | shares	(15,000)
Expired/Forfeited | shares	(16,077)
Ending balance | shares	110,000
Exercisable at June 30, 2015 | shares	110,000
Options
Beginning balance	$ 12.10
Exercised	16.33
Expired/Forfeited	3.11
Ending balance	12.84
Exercisable at June 30, 2015	$ 12.84