Basis of Presentation - Reconciliation of changes in allowance for credit losses on contracts (Details 3) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2012 Reported	Sep. 30, 2012 Reported	Sep. 30, 2012 Correction	Sep. 30, 2012 Correction	Sep. 30, 2013 Finance receivables	Mar. 31, 2013 Finance receivables	Sep. 30, 2013 Finance receivables Contracts	Sep. 30, 2012 Finance receivables Contracts	Sep. 30, 2013 Finance receivables Contracts	Sep. 30, 2012 Finance receivables Contracts	Sep. 30, 2012 Finance receivables Contracts Reported	Sep. 30, 2012 Finance receivables Contracts Reported	Sep. 30, 2012 Finance receivables Contracts Correction	Sep. 30, 2012 Finance receivables Contracts Correction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period									$ 14,138,637	$ 16,558,569	$ 14,811,173	$ 19,641,656	$ 16,090,652	$ 19,499,208	$ 35,645,655	$ 35,495,684	$ (16,003,999)	$ (15,996,476)
Discounts acquired on new volume															2,843,382	5,944,320	(2,843,382)	(5,944,320)
Provision for credit losses	3,973,104	3,261,721	6,614,895	6,364,987	308,340	318,712	2,953,381	6,046,275			3,873,216	3,246,998	6,367,646	6,260,674	293,618	214,400	2,953,380	6,046,274
Losses absorbed											(6,029,363)	(5,295,524)	(10,678,339)	(8,955,368)	(5,295,524)	(8,955,368)
Recoveries											823,996	763,687	1,699,063	1,552,303	763,687	1,552,303
Discounts accreted															(150,157)	(150,678)	150,157	150,678
Balance at end of period									$ 14,138,637	$ 16,558,569	$ 13,479,022	$ 18,356,817	$ 13,479,022	$ 18,356,817	$ 34,100,661	$ 34,100,661	$ (15,743,844)	$ (15,743,844)