Schedule of Changes in Issued and Outstanding Common Shares and Treasury Stock (Detail) - shares	9 Months Ended	12 Months Ended
	Jul. 31, 2015	Oct. 31, 2014
Equity [Abstract]
Balance, beginning of year	32,123,717	31,441,949
Shares issued under share-based compensation plans	241,632	681,768
Balance, end of current period	32,365,349	32,123,717
Balance, beginning of year	269,228	0
Shares purchased	2,562,122	269,228
Balance, end of current period	2,831,350	269,228
Shares outstanding, end of period	29,533,999	31,854,489