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Equity - Incentive Equity Awards - Additional Information (Detail) - USD ($) $ in Thousands |  |  |  |  | 9 Months Ended
--- | --- | --- | --- | --- | ---
May 15, 2017 | Feb. 01, 2017 | Jul. 11, 2016 | Feb. 01, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Stockholders Equity Note [Line Items] |  |  |  |  |  |
Stock options, outstanding |  |  |  |  | 23,631,444 |
Restricted stock units, outstanding |  |  |  |  | 11,887,491 |
Shares issued, exercise of stock options |  |  |  |  | 259,195 | 94,272
Proceeds from exercise of stock options, net of transaction costs |  |  |  |  | $ 451 | $ 136
Stock Options |  |  |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |  |  |
Percentage of outstanding shares on a fully diluted basis |  |  |  |  | 7.00% |
Stock Options | Stock Incentive Plan 2011 |  |  |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |  |  |
Stock options, Granted | 131,575 | 2,642,500 | 208,340 | 2,442,000 |  |
Stock units, Vesting Period |  | 4 years |  | 4 years |  |
Restricted Stock Units (RSUs) |  |  |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |  |  |
Percentage of outstanding shares on a fully diluted basis |  |  |  |  | 4.00% |
Restricted Stock Units (RSUs) | Stock Incentive Plan 2011 |  |  |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |  |  |
Stock units, Granted | 91,504 | 1,575,000 | 148,403 | 1,607,500 |  |
Stock units, Vesting Period | 3 years | 3 years | 3 years | 3 years |  |
Shares issued, related to the vesting of RSUs |  | 989,000 |  |  |  |
Restricted Stock Units (RSUs) | Stock Incentive Plan 2011 | Vesting Period |  |  |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |  |  |
Stock units, Granted | 2,310,000 |  |  |  |  |
Stock units, Vesting Period | 3 years |  |  |  |  |
Restricted Stock Units (RSUs) | Stock Incentive Plan 2011 | Vest over a three year period |  |  |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |  |  |
Shares issued, related to the vesting of RSUs |  |  |  |  | 494,885 |
Treasury shares for settlement of employee tax obligations |  |  |  |  | 191,899 |

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- Definition Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=96867065&loc=SL79508275-113901 + Details
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