FINANCIAL INSTRUMENTS, FAIR VALUE AND RISK MANAGEMENT - Liquidity Risk (Details) - USD ($) $ in Millions	Apr. 30, 2017	Oct. 31, 2016	Apr. 30, 2016	Oct. 31, 2015
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 92.7	$ 165.0	$ 184.7	$ 328.7
Liquidity risk
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Cash and cash equivalents	92.7
Liquidity risk | Line of credit
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Undrawn lines of credit available	$ 209.3