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v3.19.3.a.u2

Stock-based Compensation Plans - Allocation of Stock-Based Compensation by Functional Category (Parenthetical) (Detail) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2017
Officers |  |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] |  |
Accelerated vesting of equity grants | $ 30.8 | $ 30.8

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Amount of additional cost recognized for award under share-based payment arrangement from occurrence of event accelerating recognition of cost. + References No definition available. + Details
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- Details
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Balance Type: |
Period Type: |