CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income:
Loans	$ 1,060,487	$ 817,120	$ 660,792
Investments	9,160	10,247	8,913
Cash and cash equivalents	7,599	3,751	4,589
Total interest income	1,077,246	831,118	674,294
Interest expense:
Deposits	148,408	116,391	95,774
Interest expense on short-term borrowings	7,322	6,490	0
Interest expense on long-term borrowings	30,178	5,738	0
Other interest expense	0	0	41
Total interest expense	185,908	128,619	95,815
Net interest income	891,338	702,499	578,479
Less: provisions for credit losses	159,405	90,055	85,529
Net interest income after provisions for credit losses	731,933	612,444	492,950
Non-interest income:
Gains on sales of loans, net	230	135,358	121,359
(Losses) gains on derivatives and hedging activities, net	(958)	5,300	(3,996)
Other income	69,544	41,935	39,921
Total non-interest income	68,816	182,593	157,284
Non-interest expenses:
Compensation and benefits	183,996	158,975	129,709
FDIC assessment fees	19,209	14,348	6,150
Other operating expenses	182,202	175,772	139,022
Total operating expenses	385,407	349,095	274,881
Acquired intangible asset amortization expense	906	1,480	3,290
Restructuring and other reorganization expenses	0	5,398	38,311
Total non-interest expenses	386,313	355,973	316,482
Income before income tax expense	414,436	439,064	333,752
Income tax expense	164,109	164,780	139,967
Net income	250,327	274,284	193,785
Less: net loss attributable to noncontrolling interest	0	0	(434)
Net income	250,327	274,284	194,219
Preferred stock dividends	21,204	19,595	12,933
Net income attributable to SLM Corporation common stock	$ 229,123	$ 254,689	$ 181,286
Basic earnings per common share attributable to SLM Corporation (in dollars per share)	$ 0.54	$ 0.60	$ 0.43
Average common shares outstanding (in shares)	427,876	425,574	423,970
Diluted earnings per common share attributable to SLM Corporation (in dollars per share)	$ 0.53	$ 0.59	$ 0.42
Average common and common equivalent shares outstanding (in shares)	432,919	432,234	432,269