Consolidated Statements of Shareholders' Equity - USD ($)	Common stock	Treasury stock	Additional paid-in capital	Retained earnings	Total
Balance at Mar. 31, 2016	$ 580,575	$ (20,943,816)	$ 848,179,471	$ 157,783,007	$ 985,599,237
Balance (in shares) at Mar. 31, 2016	58,057,493
Increase (Decrease) in Shareholders' Equity
Net loss for the period				(1,441,815)	(1,441,815)
Restricted share award issuances	$ 2,847		(2,847)
Restricted share award issuances (in shares)	284,708
Stock-based compensation			4,797,749		4,797,749
Purchase of treasury stock		(12,953,453)			(12,953,453)
Balance at Mar. 31, 2017	$ 583,422	(33,897,269)	852,974,373	156,341,192	976,001,718
Balance (in shares) at Mar. 31, 2017	58,342,201
Increase (Decrease) in Shareholders' Equity
Net loss for the period				(20,400,686)	(20,400,686)
Restricted share award issuances	$ 2,980		(2,980)
Restricted share award issuances (in shares)	297,960
Stock-based compensation			5,138,489		5,138,489
Purchase of treasury stock		(1,326,159)			(1,326,159)
Balance at Mar. 31, 2018	$ 586,402	(35,223,428)	858,109,882	135,940,506	959,413,362
Balance (in shares) at Mar. 31, 2018	58,640,161
Increase (Decrease) in Shareholders' Equity
Net loss for the period				(50,945,905)	(50,945,905)
Restricted share award issuances	$ 2,424		(2,424)
Restricted share award issuances (in shares)	242,354
Stock-based compensation			5,476,234		5,476,234
Purchase of treasury stock		(1,261,133)			(1,261,133)
Balance at Mar. 31, 2019	$ 588,826	$ (36,484,561)	$ 863,583,692	$ 84,994,601	$ 912,682,558
Balance (in shares) at Mar. 31, 2019	58,882,515