Subsequent Events (Details) (USD $)	12 Months Ended			1 Months Ended		3 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012	Dec. 31, 2014	Nov. 30, 2014 installment	Apr. 30, 2014
Subsequent Event [Line Items]
Amount drawn from credit facility	$ 200,000,000	$ 0	$ 250,000,000
Subsequent event
Subsequent Event [Line Items]
Accelerated share repurchase amount				180,000,000
Prepayment amount				180,000,000
Value of initial share delivery				144,000,000
Average price paid (in dollars per share)				$ 43.77
Remaining repurchase amount				36,000,000
Settlement period for remaining balance				6 months
Number of installments to implement policy					2
Revolver
Subsequent Event [Line Items]
Amount drawn from credit facility						200,000,000
Revolver | Subsequent event
Subsequent Event [Line Items]
Amount drawn from credit facility				250,000,000
Voluntary Retirement Program and Headcount Reduction Program | Minimum | Subsequent event
Subsequent Event [Line Items]
Voluntary Retirement Program and Headcount reduction Program Costs					15,000,000
Voluntary Retirement Program and Headcount Reduction Program | Maximum | Subsequent event
Subsequent Event [Line Items]
Voluntary Retirement Program and Headcount reduction Program Costs					19,000,000