CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Interest income:
Loans	$ 2,314,417	$ 2,327,743	$ 1,914,554
Investments	61,412	50,810	35,304
Cash and cash equivalents	243,217	213,750	81,722
Total interest income	2,619,046	2,592,303	2,031,580
Interest expense:
Deposits	881,456	808,065	368,914
Interest expense on short-term borrowings	13,815	13,501	11,956
Interest expense on long-term borrowings	242,993	208,524	161,929
Total interest expense	1,138,264	1,030,090	542,799
Net interest income	1,480,782	1,562,213	1,488,781
Less: provisions for credit losses	408,515	345,463	633,453
Net interest income after provisions for credit losses	1,072,267	1,216,750	855,328
Non-interest income:
Gains on sales of loans, net	254,928	160,290	327,750
Gains (losses) on securities, net	467	2,678	(60,267)
Losses on derivatives and hedging activities, net	0	0	(5)
Other income	112,873	84,148	67,160
Total non-interest income	368,268	247,116	334,638
Operating expenses:
Compensation and benefits	349,387	326,554	270,354
FDIC assessment fees	51,606	45,766	20,939
Other operating expenses	235,577	246,886	260,169
Total operating expenses	636,570	619,206	551,462
Acquired intangible assets impairment and amortization expense	5,329	66,364	7,779
Total non-interest expenses	641,899	685,570	559,241
Income before income tax expense	798,636	778,296	630,725
Income tax expense	190,311	196,905	161,711
Net income	608,325	581,391	469,014
Preferred stock dividends	18,296	17,705	9,029
Net income attributable to SLM Corporation common stock	$ 590,029	$ 563,686	$ 459,985
Basic earnings per common share (in usd per share)	$ 2.73	$ 2.44	$ 1.78
Average common shares outstanding (in shares)	216,220	231,411	258,439
Diluted earnings per common share (in usd per share)	$ 2.68	$ 2.41	$ 1.76
Average common and common equivalent shares outstanding (in shares)	219,934	234,063	261,503
Declared dividends per common share (in dollars per share)	$ 0.46	$ 0.44	$ 0.44