Earnings Per Share - Reconciliation of Shares Used to Calculate Basic and Diluted Earnings Per Share (Detail)	3 Months Ended								12 Months Ended
	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Class A Common Stock [Member]
Class of Stock [Line Items]
Basic shares	25,603,452	25,576,452	25,540,341	25,470,354	25,454,762	25,435,379	25,390,486	25,316,395	25,547,650	25,399,256	25,162,686
Assumed conversion of stock options									5,336	23,066	70,170
Diluted shares	25,554,934	25,581,952	25,560,846	25,495,642	25,473,695	25,464,664	25,432,388	25,380,502	25,552,986	25,422,322	25,232,856
Class B Common Stock [Member]
Class of Stock [Line Items]
Basic shares	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,100,000	22,100,000	22,100,000
Diluted shares	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,100,000	22,100,000	22,100,000
Basic and diluted shares									22,119,966	22,119,966	22,120,391