Finance Receivables - Summary of reconciliation of changes in allowance for credit losses on contracts (Details 1) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Current period provision	$ 7,599,189	$ 5,796,648	$ 18,765,745	$ 15,182,698
Finance receivables | Contracts
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	10,953,844	11,942,694	11,325,222	12,889,082
Current period provision	7,437,522	5,658,695	18,402,211	14,799,782
Losses absorbed	(7,583,543)	(6,948,034)	(20,453,767)	(18,844,447)
Recoveries	694,452	682,830	2,228,609	2,491,768
Balance at end of period	$ 11,502,275	$ 11,336,185	$ 11,502,275	$ 11,336,185