Incremental expense on unvested equity awards

No definition available.

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- Definition

Incremental expense on vested awards

+ References

No definition available.

+ Details

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- Definition

Maximum contribution amount per employee to ESPP.

+ References

No definition available.

+ Details

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- Definition

Maximum term for stock options, in years.

+ References

No definition available.

+ Details

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- Definition

Number of Compensation Plans

+ References

No definition available.

+ Details

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- Definition

Offering period of employee stock purchase plan.

+ References

No definition available.

+ Details

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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- Definition

Percentage of vesting of share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Discount rate from fair value on offering date that participants pay for shares.

+ References

+ Details

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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- Definition

The number of shares purchased on the open market during the period for issuance to employees under the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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Stock-Based Compensation Plans and Arrangements - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014 compensation_plan	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of active stock-based compensation plans	1slm_NumberofCompensationPlans
Incremental expense on vested awards	$ 64,000slm_Incrementalexpenseonvestedawards
Incremental expense on unvested equity awards	630,000
Stock-based compensation cost	24,971,000us-gaap_ShareBasedCompensation	15,681,000us-gaap_ShareBasedCompensation	19,102,000us-gaap_ShareBasedCompensation
Weighted average period for total unrecognized compensation cost	2 years 2 months 18 days
Vesting period	3 years
Unrecognized compensation cost	15,174,000
Offering period of employee stock purchase plan	12 months
Maximum contribution amount per employee to ESPP	7,500
SLM Corporation 2012 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to be issued under plan	32,000,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to be issued under plan	15,000,000	6,000,000
Unrecognized compensation cost	118,000
Percentage of discount available to employees under ESPP	15.00%
Grants made prior to 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term for stock options (in years)	10 years
Grants made in 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term for stock options (in years)	5 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period for total unrecognized compensation cost	6 months 0 days
Unrecognized compensation cost	$ 188,000
Restricted Stock Units, RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Performance Stock Units, PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of the Company's common stock purchased by ESPP participants	0	47,176	34,729
Performance Vesting Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Performance Vesting Stock Options [Member] \| Tranche 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage per year of performance-vested options granted to management	33.33%
Performance Vesting Stock Options [Member] \| Tranche 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage per year of performance-vested options granted to management	33.33%
Performance Vesting Stock Options [Member] \| Tranche 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage per year of performance-vested options granted to management	33.33%