Earnings Per Share - Components of Denominator for Basic Earnings Per Common Share and Diluted Earnings Per Common Share (Detail)	3 Months Ended				9 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2014		Dec. 31, 2013
Basic earnings per Common Share:
Weighted-average common shares outstanding for basic earnings per share calculation	9,816,000		9,667,000		9,766,000		9,625,000
Diluted earnings per Common Share:
Weighted-average basic shares outstanding	9,816,000		9,667,000		9,766,000		9,625,000
Stock options	147,000	[1]	130,000	[1]	179,000	[1]	108,000	[1]
Weighted-average common shares outstanding for diluted earnings per share calculation	9,963,000		9,797,000		9,945,000		9,733,000

[1] During the three and nine month periods ended December 31, 2014, options to purchase 419,500 and 278,167 shares, respectively, of common stock and during the three and nine month periods ended December 31, 2013, options to purchase 99,000 and 214,000 shares of common stock, respectively, were excluded from the computation of diluted earnings per share because the exercise process of these options were greater than the average market price of the common share and the effect of their conversion would be antidilutive.