CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 91,016	$ 44,128	$ 138,715	$ 91,142
Other comprehensive income (loss):
Unrealized gains (losses) on investments	(3,180)	2,749	(2,507)	4,155
Unrealized gains on cash flow hedges	18,156	0	2,467	0
Total unrealized gains (losses)	14,976	2,749	(40)	4,155
Income tax (expense) benefit	(5,840)	(962)	(15)	(1,496)
Other comprehensive income (loss), net of tax benefit (expense)	9,136	1,787	(55)	2,659
Comprehensive income	100,152	45,915	138,660	93,801
Less: comprehensive loss attributable to noncontrolling interest	0	0	0	(434)
Total comprehensive income attributable to SLM Corporation	$ 100,152	$ 45,915	$ 138,660	$ 94,235