Allowance for Loan Losses and Credit Quality Indicators (Details) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Allowance for Loan Losses [Roll Forward]
Balance at beginning of period	$ 54,507,299	$ 48,354,994	$ 42,896,819
Provision for loan losses	114,322,525	105,705,536	95,908,363
Loan losses	(121,514,261)	(110,373,643)	(100,044,691)
Recoveries	12,471,699	11,025,950	9,475,131
Translation adjustment	193,580	(205,538)	119,372
Balance at end of period	59,980,842	54,507,299	48,354,994
Summary of loans individually and collectively evaluated for impairment [Abstract]
Bankruptcy, gross loans	5,910,206	5,646,956	4,810,026
91 days or more delinquent, excluding bankruptcy	23,536,170	20,882,907	16,236,862
Loans less than 91 days delinquent and not in bankruptcy	1,037,605,387	946,192,901	853,998,792
Gross loan balance	1,067,051,763	972,722,764	875,045,680
Unearned interest and fees	(284,956,195)	(257,637,819)	(228,974,132)
Net loans	782,095,568	715,084,945	646,071,548
Allowance for loan losses	(59,980,842)	(54,507,299)	(48,354,994)
Loans receivable, net	722,114,726	660,577,646	597,716,554
Loans individually evaluated for impairment (impaired loans) [Member]
Allowance for Loan Losses [Roll Forward]
Balance at end of period	23,410,358	19,444,641	16,829,496
Summary of loans individually and collectively evaluated for impairment [Abstract]
Bankruptcy, gross loans	5,910,206	5,646,956	4,810,026
91 days or more delinquent, excluding bankruptcy	23,536,170	20,882,907	16,236,862
Loans less than 91 days delinquent and not in bankruptcy	0	0	0
Gross loan balance	29,446,376	26,529,863	21,046,888
Unearned interest and fees	(6,036,018)	(7,085,222)	(3,649,341)
Net loans	23,410,358	19,444,641	17,397,547
Allowance for loan losses	(23,410,358)	(19,444,641)	(16,829,496)
Loans receivable, net	0	0	568,051
Loans collectively evaluated for impairment [Member]
Allowance for Loan Losses [Roll Forward]
Balance at end of period	36,570,484	35,062,658	31,525,498
Summary of loans individually and collectively evaluated for impairment [Abstract]
Bankruptcy, gross loans	0	0	0
91 days or more delinquent, excluding bankruptcy	0	0	0
Loans less than 91 days delinquent and not in bankruptcy	1,037,605,387	946,192,901	853,998,792
Gross loan balance	1,037,605,387	946,192,901	853,998,792
Unearned interest and fees	(278,920,177)	(250,552,597)	(225,324,791)
Net loans	758,685,210	695,640,304	628,674,001
Allowance for loan losses	(36,570,484)	(35,062,658)	(31,525,498)
Loans receivable, net	$ 722,114,726	$ 660,577,646	$ 597,148,503