Condensed Consolidated Statements of Shareholders' Equity - USD ($)	Common stock	Treasury stock	Additional paid-in capital	Retained earnings	Total
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
Increase (Decrease) in Shareholders' Equity
Net income for the period				6,075,059	6,075,059
Restricted share award issuances	$ 78		(78)
Restricted share award issuances (in shares)	7,750
Stock-based compensation			1,305,827		1,305,827
Purchase of treasury stock		(983,582)			(983,582)
Balance at Jun. 30, 2019	$ 588,904	(37,468,143)	864,889,441	91,069,660	919,079,862
Balance (in shares) at Jun. 30, 2019	58,890,265
Balance at Mar. 31, 2020	$ 590,833	(87,183,865)	866,809,371	196,835,859	977,052,198
Balance (in shares) at Mar. 31, 2020	59,083,290
Increase (Decrease) in Shareholders' Equity
Net income for the period				12,168,005	12,168,005
Restricted share award issuances	$ 3,516		(3,516)
Restricted share award issuances (in shares)	351,629
Stock-based compensation			1,930,902		1,930,902
Purchase of treasury stock		(1,198,214)			(1,198,214)
Balance at Jun. 30, 2020	$ 594,349	$ (88,382,079)	$ 868,736,757	$ 209,003,864	$ 989,952,891
Balance (in shares) at Jun. 30, 2020	59,434,919