Condensed 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 income/(loss)				(3,397,085)	(3,397,085)
Restricted share award issuances	$ 2,775		(2,775)
Restricted share award issuances (in shares)	277,514
Stock-based compensation			3,650,778		3,650,778
Purchase of treasury stock		(12,953,453)			(12,953,453)
Balance at Dec. 31, 2016	$ 583,350	(33,897,269)	851,827,474	154,385,922	972,899,477
Balance (in shares) at Dec. 31, 2016	58,335,007
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 income/(loss)				(16,934,691)	(16,934,691)
Restricted share award issuances	$ 2,882		(2,882)
Restricted share award issuances (in shares)	288,240
Stock-based compensation			3,977,219		3,977,219
Purchase of treasury stock		(1,084,902)			(1,084,902)
Balance at Dec. 31, 2017	$ 586,304	$ (34,982,171)	$ 856,948,710	$ 139,406,501	$ 961,959,344
Balance (in shares) at Dec. 31, 2017	58,630,441