Derivative Instruments (Details 2) - Interest rate contracts - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014	Oct. 31, 2014
Fair Value Hedges
Gains (losses) on ineffective portion of interest rate fair value hedge derivatives	$ (0.3)	$ (1.5)	$ 1.1	$ (2.5)
Gain (Loss) on Fair Value Hedges
Gains (losses) on interest rate contracts	(11.7)	31.6	40.4	(49.5)
Net accrued interest income on interest rate contracts	40.7	41.9	126.2	116.2
Gains (losses) on borrowings	11.4	(33.1)	(39.3)	47.0
Accrued interest expense on borrowings	63.2	64.3	193.4	179.7
Fair Value Hedges | Designated as hedges
Fair Value Hedges
Notional amounts	$ 8,203.4	$ 8,253.9	$ 8,203.4	$ 8,253.9	$ 8,228.4