Stockholders' Equity Repurchases of Common Shares (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016		Mar. 31, 2015
Stock repurchased and retired during period, value	$ (3,005,000)	$ (11,653,000)		$ (19,371,000)
Stock repurchased and retired at end of period, value	$ 30,364,722
February 2015
Stock repurchased and retired during period, shares	0	1,392,135
Stock repurchased and retired during period, value	$ 0	$ 11,164,329	[1]	$ 19,200,393	[1]
Stock repurchased, weighted average price per share		$ 8.02		$ 7.38
Stock repurchased and retired at end of period, shares	3,880,350	3,880,350		2,488,215
Stock repurchased and retired at end of period, value	$ 30,364,722	$ 30,364,722
Stock repurchase program, authorized amount	$ 20,000,000
Stock repurchase program expiration date	Oct. 20, 2016	Feb. 29, 2016
October 2015
Stock repurchase program, authorized amount	$ 15,000,000
Total Plan 2015
Stock repurchase program, remaining authorized repurchase amount	$ 15,000,000

[1] Amount excludes commission fees.