CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 82,926	$ 49,057	$ 174,068	$ 197,723
Other comprehensive income (loss):
Unrealized gains (losses) on investments	(525)	3,613	3,629	41,382
Unrealized losses on cash flow hedges	(1,883)	0	(1,883)	0
Total unrealized gains (losses)	(2,408)	3,613	1,746	41,382
Income tax (expense) benefit	921	(1,368)	(574)	(15,695)
Other comprehensive income (loss), net of tax benefit (expense)	(1,487)	2,245	1,172	25,687
Comprehensive income	81,439	51,302	175,240	223,410
Less: comprehensive loss attributable to noncontrolling interest	0	(333)	(434)	(1,020)
Total comprehensive income attributable to SLM Corporation	$ 81,439	$ 51,635	$ 175,674	$ 224,430