Shareholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Equity Class Of Treasury Stock [Line Items]
Options outstanding	0	0
Warrants outstanding	0	0
Other potentially dilutive securities outstanding	0	0
Common Stock
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount			$ 10,000,000
Stock repurchase program, additional authorized repurchase amount			$ 5,000,000
Stock repurchase program, expiration date		Jun. 30, 2018
Number of common shares repurchased	669,357	3,226,388
Cost of shares repurchased under common stock repurchase program	$ 991,972	$ 4,710,572
Stock repurchase program, remaining balance	$ 5,289,428	$ 5,289,428
Common Stock | Maximum
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program, authorized amount				$ 5,000,000