Employee Benefit Obligations - Summary of Pension Plan Assets as of Measurement Date (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocation, target		100.00%
Minimum [Member] | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocation, target		0.00%
Minimum [Member] | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocation, target		0.00%
Minimum [Member] | Other plan asset investments
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocation, target		0.00%
Maximum | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocation, target		60.00%
Maximum | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocation, target		40.00%
Maximum | Other plan asset investments
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocation, target		100.00%
Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2.6	$ 2.6
Pension plan asset allocations	100.00%	100.00%
Interest cost	$ 5.7	$ 6.2
Recognized net actuarial (gain) loss	$ 36.0	$ 10.6
Non-US [Member] | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	0.00%	6.00%
Non-US [Member] | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	23.00%	25.00%
Non-US [Member] | Other plan asset investments
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	77.00%	69.00%
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.6	$ 0.8
Pension plan asset allocations	100.00%	100.00%
Interest cost	$ 3.7	$ 3.7
Recognized net actuarial (gain) loss	$ 6.8	$ 3.1
UNITED STATES | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	61.00%	62.00%
UNITED STATES | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	36.00%	35.00%
UNITED STATES | Other plan asset investments
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	3.00%	3.00%
Pension Plan [Member] | Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2.6	$ 2.6	$ 3.0
Interest cost	5.7	6.2	7.4
Expected return on assets	4.2	5.2	5.8
Amortization of transition obligation	0.1	0.7	(0.1)
Recognized net actuarial (gain) loss	(0.8)	(1.3)	(1.4)
Net periodic cost (benefit)	5.0	5.6	5.9
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.6	0.8	0.5
Interest cost	3.7	3.7	3.8
Expected return on assets	5.2	5.6	5.2
Amortization of transition obligation	0.0	0.0	0.0
Recognized net actuarial (gain) loss	(0.7)	(0.2)	(0.1)
Net periodic cost (benefit)	$ (0.2)	$ (0.9)	$ (0.8)