Quarterly Information (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Selected Quarterly Financial Information [Abstract]
Total revenues	$ 159,265,000	$ 137,749,000	$ 136,875,000	$ 139,324,000	$ 160,837,000	$ 146,533,000	$ 151,258,000	$ 157,918,000	$ 573,213,402	$ 616,545,364	$ 585,186,753
Provision for credit losses	29,276,000	40,632,000	40,463,000	46,602,000	45,412,000	59,609,000	68,620,000	85,822,000	156,973,220	259,463,199	186,207,341
General and administrative expenses	71,619,000	65,909,000	62,948,000	68,125,000	73,178,000	64,951,000	69,694,000	71,650,000	268,600,159	279,473,798	299,975,305
Interest expense	11,757,000	11,690,000	12,543,000	12,242,000	12,185,000	14,070,000	13,032,000	11,174,000	48,232,287	50,462,594	33,424,788
Income tax expense (benefit)	11,555,000	2,853,000	4,839,000	2,816,000	5,430,000	2,097,000	549,000	(2,162,000)	22,062,509	5,913,783	11,659,482
Net income	$ 35,058,000	$ 16,665,000	$ 16,082,000	$ 9,539,000	$ 24,632,000	$ 5,806,000	$ (637,000)	$ (8,566,000)	$ 77,345,227	$ 21,231,990	$ 53,919,837
Net income (loss) per common share:
Basic (in dollars per share)	$ 6.19	$ 2.89	$ 2.78	$ 1.65	$ 4.27	$ 1.01	$ (0.11)	$ (1.49)	$ 13.45	$ 3.69	$ 8.88
Diluted (in dollars per share)	$ 6.09	$ 2.84	$ 2.71	$ 1.62	$ 4.20	$ 0.99	$ (0.11)	$ (1.49)	$ 13.19	$ 3.60	$ 8.47