Finance Receivables - Reconciliation of changes in allowance for credit losses on direct loans (Details 3) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for credit losses	$ 5,187,832	$ 5,796,648	$ 5,154,235	$ 4,231,815	$ 4,181,286	$ 4,183,035	$ 3,973,104	$ 2,641,791	$ 20,370,530	$ 14,979,216	$ 13,391,875
Finance receivables | Direct Loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year							590,278		590,278	467,917	492,184
Provision for credit losses									362,364	285,375	139,493
Losses absorbed									(278,333)	(192,156)	(190,871)
Recoveries									28,481	29,142	27,111
Balance at end of year				$ 702,790				$ 590,278	$ 702,790	$ 590,278	$ 467,917