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Commitments and Contingencies - Additional Information (Detail) | 6 Months Ended
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Jun. 30, 2019 USD ($)
Operating Expense [Member] |
Loss Contingencies [Line Items] |
Contingency reserve | $ 40,000,000
SLM BankCo [Member] | Indemnification Matters [Member] |
Loss Contingencies [Line Items] |
Reserve for estimated amounts and costs incurred | $ 0

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- Definition Aggregate carrying amount of the estimated litigation liability for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.25) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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