Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 19,940,946	$ 22,221,759	$ 16,768,294
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	284,594	287,839	266,686
Gain on sale of property and equipment	(11,339)	(26,945)	(25,792)
Provision for credit losses	13,391,875	12,367,593	15,611,544
Amortization of dealer discounts	(11,482,251)	(12,348,448)	(10,941,553)
Deferred income taxes	696,339	245,273	(1,440,668)
Share-based compensation	812,004	551,912	660,328
Change in fair value of interest rate swap agreements	504,852		(495,136)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	14,294	(70,425)	101,807
Accounts payable and accrued expenses	793,150	(596,958)	1,068,422
Income taxes receivable	394,536	(731,289)	(187,065)
Deferred revenues	281,155	(25,432)	(29,243)
Net cash provided by operating activities	25,620,155	21,874,879	21,357,624
Cash flows from investing activities:
Purchase and origination of finance contracts	(141,562,259)	(134,347,957)	(134,049,373)
Principal payments received	131,080,264	122,157,971	101,715,052
Decrease (increase) in assets held for resale	169,337	(317,861)	14,991
Purchase of property and equipment	(271,003)	(320,537)	(393,782)
Proceeds from sale of property and equipment	14,951	72,170	42,670
Net cash used in investing activities	(10,568,710)	(12,756,214)	(32,670,442)
Cash flows from financing activities:
Net proceeds (repayment of) from line of credit	13,500,000	(6,000,000)	10,725,029
Payment of cash dividend	(29,844,516)	(3,593,021)
Increase (decrease) in drafts payable	494,232	(276,530)	937,402
Proceeds from exercise of stock options	612,465	830,277	55,610
Excess tax benefits from exercise of stock options, vesting of restricted share awards and issuance of performance share awards	181,036	706,123	78,423
Net cash (used in) provided by financing activities	(15,056,783)	(8,333,151)	11,796,464
Net (decrease) increase in cash	(5,338)	785,514	483,646
Cash, beginning of year	2,803,054	2,017,540	1,533,894
Cash, end of year	2,797,716	2,803,054	2,017,540
Supplemental disclosure of noncash investing and financing activities:
Decrease in accumulated other comprehensive loss for change in fair value of interest rate swap agreements			178,090
Shortfall of tax benefits from vesting of restricted share awards and performance share awards			$ (1,450)