Employee Benefit Obligations - Schedule of Plan Assets (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 192.7	$ 189.5
Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	69.5	59.6
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	123.2	129.9
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	34.0	31.6
Common Stock [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	22.2	18.6
Common Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Common Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	11.8	13.0
Equity Securities, Foreign-listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	12.7	18.9
Equity Securities, Foreign-listed [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	10.4	10.5
Equity Securities, Foreign-listed [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Equity Securities, Foreign-listed [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2.3	8.4
Life insurance contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	37.0	35.5
Life insurance contracts [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Life insurance contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Life insurance contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	37.0	35.5
Other benefit plan assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	35.1	33.9
Other benefit plan assets [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Other benefit plan assets [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Other benefit plan assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	35.1	33.9
U.S. Corporate and Government Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26.7	25.0
U.S. Corporate and Government Bonds [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	19.6	18.2
U.S. Corporate and Government Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
U.S. Corporate and Government Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	7.1	6.8
Benefit Plan Assets, Foreign Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	13.7	8.1
Benefit Plan Assets, Foreign Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	13.7	8.1
Benefit Plan Assets, Foreign Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Benefit Plan Assets, Foreign Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Foreign Government Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		11.2
Foreign Government Bonds [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0.0
Foreign Government Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0.0
Foreign Government Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		11.2
Real Estate Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	7.5	7.2
Real Estate Investments [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1.7	1.2
Real Estate Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Real Estate Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5.8	6.0
Foreign Corporate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26.0	18.1
Foreign Corporate Bonds [Member] | Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1.9	3.0
Foreign Corporate Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0.0	0.0
Foreign Corporate Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 24.1	$ 15.1
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	100.00%	100.00%
Defined Benefit Plan, Fair Value of Plan Assets	$ 77.7	$ 72.6	$ 78.0
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%
Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan asset allocations	100.00%	100.00%
Defined Benefit Plan, Fair Value of Plan Assets	$ 115.0	$ 116.9	$ 126.5
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%