CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 45,724	$ 82,926	$ 184,439	$ 174,068
Other comprehensive income (loss):
Unrealized gains (losses) on investments	2,008	(525)	(499)	3,629
Unrealized losses on cash flow hedges	(21,751)	(1,883)	(19,284)	(1,883)
Total unrealized (losses) gains	(19,743)	(2,408)	(19,783)	1,746
Income tax benefit (expense)	7,676	921	7,661	(574)
Other comprehensive (loss) income, net of tax benefit (expense)	(12,067)	(1,487)	(12,122)	1,172
Comprehensive income	33,657	81,439	172,317	175,240
Less: comprehensive loss attributable to noncontrolling interest	0	0	0	(434)
Total comprehensive income attributable to SLM Corporation	$ 33,657	$ 81,439	$ 172,317	$ 175,674