Property and Equipment - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2017	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Property Plant And Equipment [Line Items]
Depreciation expense related to property and equipment	$ 56.5	$ 80.1	$ 75.3	$ 75.3
Accumulated depreciation related to property plant and equipment under capital leases		24.4	22.2
Assets Held Under Capital Leases
Property Plant And Equipment [Line Items]
Capital lease assets included in property and equipment		$ 36.5	$ 35.4

The total gross amount less the charge for the use of the long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

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The total charge for the use of long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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