CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($)	Total	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Employee Stock Option [Member]
Common Stock, Shares, Outstanding	9,119,443
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	25,276
Balances at Mar. 31, 2018	$ 541,107,852	$ 175,887,227	$ 391,275,705	$ (26,055,080)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Proceeds from exercise of stock options, including tax benefits	$ 1,815,406
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	8,426
Issuance of restricted common stock under stock option plan	$ 1,914,349	1,914,349
Stock option expense	1,063,637	1,063,637
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
Net income	(6,965,649)		(6,965,649)
Balances at Sep. 30, 2018	$ 564,990,675	180,680,619	384,310,056	0
Common Stock, Shares, Outstanding	9,140,273
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	4,446
Balances at Jun. 30, 2018	$ 517,272,675	178,791,182	369,772,411	(31,290,918)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Proceeds from exercise of stock options, including tax benefits	$ 386,468	386,468
Stock Repurchased and Retired During Period, Shares	0
Stock Repurchased and Retired During Period, Value			0
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	8,426
Issuance of restricted common stock under stock option plan	$ 963,559	963,559
Stock option expense	539,410	539,410
Other comprehensive income	0			0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	31,290,918
Net income	14,537,645		14,537,645
Balances at Sep. 30, 2018	$ 564,990,675	180,680,619	384,310,056	0
Common Stock, Shares, Outstanding	9,153,145
Common Stock, Shares, Outstanding	9,284,118
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	55,472				55,472
Balances at Mar. 31, 2019	$ 552,116,625	198,125,649	353,990,976	0
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Proceeds from exercise of stock options, including tax benefits	$ 3,654,097
Stock Repurchased and Retired During Period, Shares	(1,392,180)
Stock Repurchased and Retired During Period, Value			(190,010,912)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	(1,568)
Issuance of restricted common stock under stock option plan	$ 13,129,717	13,129,717
Stock option expense	3,226,110	3,226,110
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0
Net income	12,828,400		12,828,400
Balances at Sep. 30, 2019	$ 394,944,037	218,135,573	176,808,464	0
Common Stock, Shares, Outstanding	9,181,305
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	15,706
Balances at Jun. 30, 2019	$ 549,660,061	208,876,263	340,783,798	0
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Proceeds from exercise of stock options, including tax benefits	$ 977,522	977,522
Stock Repurchased and Retired During Period, Shares	(1,251,103)
Stock Repurchased and Retired During Period, Value			(168,195,335)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	(66)
Issuance of restricted common stock under stock option plan	$ 6,677,016	6,677,016
Stock option expense	1,604,772	1,604,772
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0
Net income	4,220,001		4,220,001
Balances at Sep. 30, 2019	$ 394,944,037	$ 218,135,573	$ 176,808,464	$ 0
Common Stock, Shares, Outstanding	7,945,842