Stock-Based Compensation Plans and Arrangements - Stock Option Activity (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Options, Outstanding, beginning balance	3,851,120
Granted, Options	16,132
Exercised, Options	(2,196,575)	[1],[2]
Canceled, Options	(148,159)
Spin-off adjustment, Options	14,632,601	[3]
Number of Options, Outstanding, ending balance	16,155,119	[4],[5]
Number of Options, Exercisable, ending balance	12,985,828
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price per Share, Outstanding, beginning balance	$ 14.60
Granted, Weighted Average Exercise Price per Share	$ 24.24
Exercised, Weighted Average Exercise Price per Share	$ 6.19	[1],[2]
Canceled, Weighted Average Exercise Price per Share	$ 21.86
Spin-Off Adjustment, Weighted Average Exercise Price	$ 8.22	[3]
Weighted Average Exercise Price per Share, Outstanding, ending balance	$ 9.91	[4],[5]
Weighted Average Exercise Price per Share, Exercisable, ending balance	$ 8.32
Weighted Average Remaining Contractual Term, Outstanding, ending balance	3 years 1 month 27 days	[4],[5]
Weighted Average Remaining Contractual Term, Exercisable, ending balance	3 years 2 months 22 days
Aggregate Intrinsic Value, Outstanding, ending balance	$ 62,144	[4],[5],[6]
Aggregate Intrinsic Value, Exercisable, ending balance	$ 50,154	[6]

[1] Fifty-three thousand was received from option exercises for the year ended December 31, 2014. The actual tax benefit realized for the tax deductions from option exercises totaled $4,853 for the year ended December 31, 2014.

[2] The total intrinsic value of options exercised was $11,430, $8,467 and $5,410 for the years ended December 31, 2014, 2013 and 2012, respectively.

[3] Represents the adjustment to preserve the intrinsic value of the outstanding equity awards held by SLM and Navient employees.

[4] For net-settled options, gross number is reflected.

[5] Represents the adjustment to preserve the intrinsic value of the outstanding equity awards held by SLM and Navient employees. (5) As of December 31, 2014, there was $362 of unrecognized compensatio

[6] The aggregate intrinsic value represents the total intrinsic value (the aggregate difference between our closing stock price on December 31, 2014 and the exercise price of in-the-money options) that would have been received by the option holders if all in-the-money options had been exercised on December 31, 2014.