Property, Plant, and Equipment - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Depreciation [Abstract]
Depreciation expense	$ 91.6	$ 83.6	$ 186.2	$ 166.0
Incremental depreciation			13.5
Purchases of property, plant, and equipment included in accounts payable			$ 47.6		$ 29.8