CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Interest income:
Loans	$ 458,044,000	$ 431,804,000
Investments	5,479,000	2,728,000
Cash and cash equivalents	1,515,000	1,626,000
Total interest income	465,038,000	436,158,000
Interest expense:
Deposits	49,537,000	66,598,000
Interest expense on short-term borrowings	2,875,000	3,202,000
Interest expense on long-term borrowings	37,594,000	35,244,000
Total interest expense	90,006,000	105,044,000
Net interest income	375,032,000	331,114,000
Less: provisions for credit losses	98,050,000	(225,767,000)
Net interest income after provisions for credit losses	276,982,000	556,881,000
Non-interest income:
Gains on sales of loans, net	9,881,000	399,111,000
Gains (losses) on derivatives and hedging activities, net	(5,000)	28,000
Other income	12,049,000	14,288,000
Total non-interest income	21,925,000	413,427,000
Operating expenses:
Compensation and benefits	71,981,000	71,581,000
FDIC assessment fees	5,684,000	5,188,000
Other operating expenses	54,341,000	47,730,000
Total operating expenses	132,006,000	124,499,000
Acquired intangible assets amortization expense	733,000	0
Restructuring expenses	0	1,077,000
Total non-interest expenses	132,739,000	125,576,000
Income before income tax expense	166,168,000	844,732,000
Income tax expense	37,356,000	203,525,000
Net income	128,812,000	641,207,000
Preferred stock dividends	1,275,000	1,201,000
Net income attributable to SLM Corporation common stock	$ 127,537,000	$ 640,006,000
Basic earnings per common share (in dollars per share)	$ 0.46	$ 1.77
Average common shares outstanding (in shares)	276,977	361,042
Diluted earnings per common share (in dollars per share)	$ 0.45	$ 1.75
Average common and common equivalent shares outstanding (in shares)	280,654	366,240
Declared dividends per common share (in dollars per share)	$ 0.11	$ 0.03