CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($)	Total	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]
Common Stock, Shares, Issued	8,812,250
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	33,702
Balances at Mar. 31, 2016	$ 391,901,581	$ 138,835,064	$ 276,000,862	$ (22,934,345)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Proceeds from exercise of stock options, including tax benefits	$ 595,343
Stock Repurchased and Retired During Period, Shares	(95,703)
Stock Repurchased and Retired During Period, Value			(4,995,809)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	32,700
Issuance of restricted common stock under stock option plan	$ 1,320,036	1,320,036
Stock option expense	3,490,662	3,490,662
Other comprehensive income	(4,848,530)			(4,848,530)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0
Net income	73,600,294		73,600,294
Balances at Mar. 31, 2017	$ 461,063,577	144,241,105	344,605,347	(27,782,875)
Common Stock, Shares, Issued	8,782,949
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	389,888
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Proceeds from exercise of stock options, including tax benefits	$ 25,323,531
Stock Repurchased and Retired During Period, Shares	(58,728)
Stock Repurchased and Retired During Period, Value			(4,614,331)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	5,334
Issuance of restricted common stock under stock option plan	$ 1,564,048	1,564,048
Stock option expense	2,353,214	2,353,214
Other comprehensive income	1,727,795			1,727,795
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0
Net income	53,690,018		53,690,018
Balances at Mar. 31, 2018	$ 541,107,852	175,887,227	391,275,705	(26,055,080)
Common Stock, Shares, Issued	9,119,443
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 2,405,329
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	92,428
Proceeds from exercise of stock options, including tax benefits	$ 5,997,948
Stock Repurchased and Retired During Period, Shares	(665,020)
Stock Repurchased and Retired During Period, Value			(74,519,863)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	737,267
Issuance of restricted common stock under stock option plan	$ 12,248,507	12,248,507
Stock option expense	3,991,967	3,991,967
Other comprehensive income	(5,235,838)			(5,235,838)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	(31,290,918)			(31,290,918)
Net income	37,235,134		37,235,134
Balances at Mar. 31, 2019	$ 552,116,625	$ 198,125,649	$ 353,990,976	$ 0
Common Stock, Shares, Issued	9,284,118
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 0