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Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions |  |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Mar. 30, 2020 | Mar. 27, 2020 | Mar. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Income Tax Disclosure [Line Items] |  |  |  |  |  |  |
Federal income tax rate |  |  |  | 21.00% | 21.00% | 21.00% | 35.00%
Increase (decrease) in net income due to exemption from complementary tax |  |  |  | $ 4.0 | $ (54.0) |  |
Increase (decrease) in diluted earnings per share due to exemption from complementary tax |  |  |  | $ 0.01 | $ (0.10) |  |
Possible decrease in unrecognized tax benefits within next 12 months |  |  |  | $ 30.0 |  |  |
Macau [Member] | MGM Grand Paradise SA [Member] |  |  |  |  |  |  |
Income Tax Disclosure [Line Items] |  |  |  |  |  |  |
Macau's complementary tax rate on distributions of gaming profits (as a percent) | 12.00% |  |  | 12.00% |  |  |
Complementary tax |  |  |  | $ 1,500.0 |  |  |
Annual payments under the extended annual fee arrangement |  |  |  |  | $ 1.0 | $ 1.0 | $ 1.0
Payments under the extended annual fee arrangement |  |  | $ 0.3 |  |  |  |
Coronavirus Aid Relief And Economic Security Act |  |  |  |  |  |  |
Income Tax Disclosure [Line Items] |  |  |  |  |  |  |
Net operating losses carryback period |  | 5 years |  |  |  |  |
Income tax receivable |  | $ 206.0 |  |  |  |  |
Income tax benefit realized |  | $ 83.0 |  |  |  |  |

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