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Employee Benefit Plan - Additional Information (Detail) - Zillow Merger - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
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Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Company's contribution based on employee contribution (up to) |  |  | 4.00% |
Company's expense related to its defined contribution 401(k) retirement plans | $ 6.1 | $ 5.6 | $ 18.9 | $ 15.7

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- Definition Percentage employer matches of the employee's percentage contribution matched. + References No definition available. + Details
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- Details
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