Loans Held for Investment - Narrative (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Jul. 01, 2006	Jun. 30, 2006	Sep. 30, 1993
Receivables [Abstract]
Percent of private loans indexed to LIBOR	22.00%	23.00%
Tier 1 of government guarantee (at least)	97.00%		97.00%
Tier 2 of government guarantee				98.00%
Tier 3 of government guarantee					100.00%
Estimated weighted average life of student loans	5 years 7 months 6 days	5 years 7 months 6 days