Leases - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2019	Sep. 30, 2018
Leased Assets [Line Items]
Operating lease expense	$ 36.0	$ 49.0	$ 45.9
Vehicles and Equipment | Minimum
Leased Assets [Line Items]
Capital lease, term of contract		1 year
Vehicles and Equipment | Maximum
Leased Assets [Line Items]
Capital lease, term of contract		5 years
Building and Equipment | Minimum
Leased Assets [Line Items]
Operating lease, term of contract		1 month
Building and Equipment | Maximum
Leased Assets [Line Items]
Operating lease, term of contract		10 years