Certain Balance Sheet Information - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2016	Sep. 30, 2016
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 33.3	$ 47.5
China | RMB
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	9.0	6.5
Subsidiaries | Outside of the United States
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	28.8	41.9
Subsidiaries | Outside of the United States | Currencies other than U.S. dollar
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 25.3	$ 36.9