CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest income:
Loans	$ 454,045	$ 336,739	$ 884,093	$ 661,496
Investments	1,694	2,201	3,641	4,344
Cash and cash equivalents	6,572	3,155	11,808	5,743
Total interest income	462,311	342,095	899,542	671,583
Interest expense:
Deposits	90,605	50,730	168,061	95,583
Interest expense on short-term borrowings	1,128	1,194	3,521	2,430
Interest expense on long-term borrowings	29,628	20,278	54,396	35,601
Total interest expense	121,361	72,202	225,978	133,614
Net interest income	340,950	269,893	673,564	537,969
Less: provisions for credit losses	63,267	50,215	117,198	75,511
Net interest income after provisions for credit losses	277,683	219,678	556,366	462,458
Non-interest income:
Gains on sales of loans, net	2,060	0	2,060	0
Losses on sales of securities, net	(1,549)	0	(1,549)	0
Losses on derivatives and hedging activities, net	(5,268)	(3,609)	(1,376)	(8,987)
Other income	12,295	10,629	21,937	21,975
Total non-interest income	7,538	7,020	21,072	12,988
Non-interest expenses:
Compensation and benefits	60,245	51,007	128,562	106,471
FDIC assessment fees	8,001	6,622	16,797	13,851
Other operating expenses	66,977	53,622	114,738	93,606
Total operating expenses	135,223	111,251	260,097	213,928
Acquired intangible asset amortization expense	92	117	184	234
Total non-interest expenses	135,315	111,368	260,281	214,162
Income before income tax expense	149,906	115,330	317,157	261,284
Income tax expense	40,074	44,713	81,071	95,724
Net income	109,832	70,617	236,086	165,560
Preferred stock dividends	3,920	3,974	7,317	9,549
Net income attributable to SLM Corporation common stock	$ 105,912	$ 66,643	$ 228,769	$ 156,011
Basic earnings per common share attributable to SLM Corporation (in dollars per share)	$ 0.24	$ 0.15	$ 0.53	$ 0.36
Average common shares outstanding (in shares)	435,187	431,245	434,573	430,572
Diluted earnings per common share attributable to SLM Corporation (in dollars per share)	$ 0.24	$ 0.15	$ 0.52	$ 0.35
Average common and common equivalent shares outstanding (in shares)	439,445	438,115	439,212	438,424