Summary of Significant Accounting Policies (Additional Disclosures) (Details) (USD $)	12 Months Ended
	Mar. 31, 2013 segments states offices	Mar. 31, 2012	Mar. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Number of reportable segments	1
Number of offices recording goodwill	89
Impairment of Long-Lived Assets [Abstract]
Impairment charge	$ 0	$ 0	$ 25,000
Fair Value of Financial Instruments [Abstract]
Average loan life	8 months
Income Taxes [Abstract]
Income tax position, likelihood of being sustained (in hundredths)	50.00%
Supplemental Cash Flow Information [Abstract]
Interest paid	16,028,399	11,076,970	9,840,627
Income taxes paid	66,921,031	60,760,661	50,487,423
Concentration of Risk [Abstract]
Number of states in which entity operates	13
Number of states with largest concentration of revenue	4
Percentage of total revenues in the four largest sates (in hundredths)	56.00%	56.00%	57.00%
Advertising Costs [Abstract]
Advertising	$ 14,849,980	$ 14,228,002	$ 13,056,444
Customer lists [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life (in years)	11 years
Customer lists [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life (in years)	5 years
Customer lists [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, useful life (in years)	20 years