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Employee Benefit Plan - Additional Information (Detail) - Zillow Merger - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
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Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
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 | $ 8.0 | $ 6.4 | $ 15.7 | $ 12.8

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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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