Commitments and Contingencies - Commitments (Details) $ in Millions	Sep. 30, 2018 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Purchase obligation	$ 610.9
Excess purchase commitments and obsolete materials liability	$ 23.6

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

No definition available.