Finance Receivables - Reconciliation of the changes in the allowance for credit losses on direct loans (Details 3) (USD $)	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for credit losses	$ 3,542,077	$ 3,484,811	$ 3,261,721	$ 3,103,266	$ 2,600,949	$ 3,507,659	$ 3,209,524	$ 3,049,461	$ 13,391,875	$ 12,367,593	$ 15,611,544
Direct Loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of year				492,184				378,418	492,184	378,418	382,869
Provision for credit losses									139,493	182,062	125,937
Losses absorbed									(190,871)	(93,041)	(173,970)
Recoveries									27,111	24,745	43,582
Balance at end of year	$ 467,917				$ 492,184				$ 467,917	$ 492,184	$ 378,418