CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest income:
Loans	$ 564,698	$ 485,997	$ 1,672,082	$ 1,370,090
Investments	2,145	1,340	5,272	4,981
Cash and cash equivalents	23,548	10,260	53,212	22,068
Total interest income	590,391	497,597	1,730,566	1,397,139
Interest expense:
Deposits	143,393	105,093	405,977	273,154
Interest expense on short-term borrowings	1,400	1,156	3,700	4,677
Interest expense on long-term borrowings	40,533	34,715	116,675	89,111
Total interest expense	185,326	140,964	526,352	366,942
Net interest income	405,065	356,633	1,204,214	1,030,197
Less: provisions for credit losses	99,526	70,047	256,691	187,245
Net interest income after provisions for credit losses	305,539	286,586	947,523	842,952
Non-interest income (loss):
Gains on sales of loans, net	0	0	0	2,060
Losses on sales of securities, net	0	0	0	(1,549)
Gains (losses) on derivatives and hedging activities, net	1,961	(4,949)	21,460	(6,325)
Other income (loss)	15,280	(80,702)	31,313	(58,765)
Total non-interest income (loss)	17,241	(85,651)	52,773	(64,579)
Non-interest expenses:
Compensation and benefits	64,980	62,260	210,213	190,822
FDIC assessment fees	8,814	9,136	23,788	25,933
Other operating expenses	79,827	79,328	198,573	194,250
Total non-interest expenses	153,621	150,724	432,574	411,005
Income before income tax expense (benefit)	169,159	50,211	567,722	367,368
Income tax expense (benefit)	40,701	(53,667)	130,798	27,404
Net income	128,458	103,878	436,924	339,964
Preferred stock dividends	4,153	4,124	12,952	11,441
Net income attributable to SLM Corporation common stock	$ 124,305	$ 99,754	$ 423,972	$ 328,523
Basic earnings per common share attributable to SLM Corporation (in dollars per share)	$ 0.29	$ 0.23	$ 0.99	$ 0.76
Average common shares outstanding (in shares)	424,149,000	435,468,000	429,295,000	434,875,000
Diluted earnings per common share attributable to SLM Corporation (in dollars per share)	$ 0.29	$ 0.23	$ 0.98	$ 0.75
Average common and common equivalent shares outstanding (in shares)	427,336,000	440,019,000	432,572,000	439,484,000
Declared dividends per common share attributable to SLM Corporation (in dollars per share)	$ 0	$ 0	$ 0.09	$ 0