Earnings Per Share - Reconciliation of Shares Used to Calculate Basic and Diluted Earnings Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Class A Common Stock
Class of Stock [Line Items]
Basic shares (shares)	25,834,636	25,781,146	25,815,533	25,746,797
Assumed conversion of restricted shares (shares)	658	2,038	3,284	349
Diluted shares (shares)	25,835,294	25,783,184	25,818,817	25,747,146
Class B Common Stock
Class of Stock [Line Items]
Basic shares (shares)	22,000,000	22,000,000	22,000,000	22,100,000
Diluted shares (shares)	22,000,000	22,000,000	22,000,000	22,100,000
Basic and diluted shares (shares)	22,009,596	22,009,725	22,009,682	22,079,544