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Fair Value Measurements - Additional Information (Details) $ in Millions | 6 Months Ended |
--- | --- | ---
Jun. 30, 2020 USD ($) engine | Jun. 30, 2019 USD ($) engine | Dec. 31, 2019 USD ($)
Derivative [Line Items] |  |  |
Fair value of notes receivable | $ 171.3 |  | $ 39.7
Fair value of notes payable | 1,498.8 |  | 1,262.6
Increase in interest expense | 0.6 | $ (0.4) |
Asset write-down | $ 9.1 | $ 4.4 |
Number of assets impaired | engine | 2 | 4 |
Remaining book value | $ 30.5 |  |
Number of assets previously impaired | engine | 12 |  |
Fair value, recurring | Fair value, inputs, Level 2 | Interest rate contract |  |  |
Derivative [Line Items] |  |  |
Notional amount, liability | $ 5.4 |  |
Assets at fair value |  |  | $ 1.7
Assets To Be Sold Or Parted Out |  |  |
Derivative [Line Items] |  |  |
Number of assets impaired | engine | 5 |  |

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