Debt - Long-term Debt and Capital Lease Maturities (Details) - USD ($) $ in Millions	Mar. 31, 2019	Sep. 30, 2018
Debt Disclosure [Abstract]
Maturities of long term debt in one year	$ 10.0
Maturities of long term debt in two years	60.0
Maturities of long term debt in three years	110.0
Maturities of long term debt in four years	10.0
Maturities of long term debt in five years	10.0
Maturities of long term debt thereafter	3,379.2
Total long term debt payments due	3,579.2
Maturities of capital leases in one year	4.8
Maturities of capital leases in two years	4.8
Maturities of capital leases in three years	4.7
Maturities of capital leases in four years	4.6
Maturities of capital leases in five years	5.3
Maturities of capital leases thereafter	72.6
Total long term debt payments due	96.8
Less: Interest on capital leases	(48.9)
Present value of capital lease payments (1)	47.9
Current portion of capital leases	1.6	$ 0.0
Noncurrent portion of capital leases	$ 46.3