Earnings Per Share - Additional Information (Detail) - shares	6 Months Ended	18 Months Ended
	Apr. 30, 2017	Apr. 30, 2017	Oct. 31, 2016
Class of Stock [Line Items]
Repurchase of common stock (shares)		0
Class A Common Stock
Class of Stock [Line Items]
Percentage of shares outstanding used in two class method calculation	40.00%
Voting rights	The Class A Common Stock has no voting rights unless four quarterly cumulative dividends upon the Class A Common Stock are in arrears.
Treasury shares (in shares)	16,451,501	16,451,501	16,500,129
Class B Common Stock
Class of Stock [Line Items]
Percentage of shares outstanding used in two class method calculation	60.00%
Voting rights	The Class B Common Stock has full voting rights.
Treasury shares (in shares)	12,550,275	12,550,275	12,550,275
Board Of Director Authorized
Class of Stock [Line Items]
Number of shares authorized to be purchased (shares)	4,000,000	4,000,000
Treasury shares (in shares)	3,294,513	3,294,513
Board Of Director Authorized | Class A Common Stock
Class of Stock [Line Items]
Treasury shares (in shares)	1,425,452	1,425,452
Board Of Director Authorized | Class B Common Stock
Class of Stock [Line Items]
Treasury shares (in shares)	1,869,061	1,869,061
Stock Repurchase Committee Authorized
Class of Stock [Line Items]
Number of shares authorized to be purchased (shares)			110,241