Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Income Taxes [Line Items]
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation	$ 101.6	$ 84.2
Deferred Tax Assets, Valuation Allowance	512.1	894.2
Deferred Tax Assets, Insurance Receivables	0.0	21.2
Deferred Tax Assets, Investment in Subsidiaries	51.1	217.3
Deferred tax liabilities (Note 19)	546.0	574.5
Deferred tax assets (Note 19)	798.7	548.6
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Restructuring Charges	8.9	4.1
Deferred Tax Assets, Inventory	32.6	35.3
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Other	17.6	14.4
Deferred Tax Assets, Operating Loss Carryforwards	992.3	871.4
Deferred Tax Assets Prepaid Royalties	6.0	6.3
Deferred Tax Assets, Unrealized Losses on Trading Securities	16.4	19.9
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Policyholder Liabilities	23.3	43.3
Deferred Tax Assets, Goodwill and Intangible Assets	3.7	6.1
Deferred Tax Assets, Investments	0.0	13.1
Deferred Tax Assets, Other	57.3	106.2
Deferred Tax Assets, Gross	1,310.8	1,442.8
Deferred Tax Liabilities, Property, Plant and Equipment	20.1	15.1
Deferred Tax Liabilities, Unrealized Gains on Trading Securities	367.8	23.8
Deferred Tax Liabilities, Intangible Assets	813.4	841.1
Deferred Tax Liabilities, Investments	39.3	87.4
Deferred Tax Liabilities, Insurance Reserves	5.0	14.9
Deferred Tax Liability, Redemption of Long Term Debt	10.2	11.8
Deferred Tax Liabilities, Other	46.3	72.3
Deferred Tax Liabilities, Gross	1,302.1	1,066.4
Deferred Tax Liabilities, Net	$ 503.4	$ 517.8