Income Taxes (Income Tax Reconciliation) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Income tax expense reconciliation to U.S. federal tax rate [Abstract]
Expected income tax									$ 23,394,720	$ 7,330,983	$ 18,874,500
Increase (reduction) in income taxes resulting from:
State tax (excluding state tax credits), net of federal benefit									2,053,524	3,398,271	1,576,915
Federal tax credits (net)									1,173,435	7,616,236	0
State tax credits									0	(500,000)	(3,704,580)
Revalue deferred tax assets and liabilities									0	0	(852,523)
Uncertain tax positions									(2,107,263)	(167,455)	(183,929)
Nondeductible penalties									8,274	4,562,830	2,210
Executive compensation limitation under Section 162(m)									1,203,203	1,305,975	37,457
Excess tax benefits related to equity compensation									(996,769)	(612,987)	(287,703)
Prior year adjustments									(30,953)	(672,358)	106,075
Other, net									769,298	(277,058)	412,635
Foreign income adjustments									0	0	626,583
Income tax expenses (benefit)	$ 11,409,000	$ 2,418,000	$ 3,767,000	$ 5,527,000	$ 2,721,000	$ 356,000	$ 1,312,000	$ 2,363,000	23,120,599	6,751,965	15,981,057
Discontinued Operations, Disposed of by Sale
Income tax expense reconciliation to U.S. federal tax rate [Abstract]
Expected income tax									0	0	491,783
Increase (reduction) in income taxes resulting from:
Other, net									0	0	(53,174)
Foreign income adjustments									0	0	187,974
Income tax expenses (benefit)									$ 0	$ 0	$ 626,583