CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income attributable to SLM Corporation	$ 65,915	$ 47,699
Other comprehensive income (loss):
Unrealized gains on investments	3,024	673
Unrealized losses on cash flow hedges	(24,374)	(15,689)
Total unrealized losses	(21,350)	(15,016)
Income tax benefit	8,140	5,825
Other comprehensive loss, net of tax benefit	(13,210)	(9,191)
Total comprehensive income attributable to SLM Corporation	$ 52,705	$ 38,508