Stock-based Compensation - Additional Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of common shares available for grant	2,900		2,900
Percentage of base pay and annual incentive compensation deferred			100.00%
Percentage of long term incentive compensation plan deferred			90.00%
Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense related to director deferred compensation	$ 23	$ 43	$ 75	$ 152
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum rate of stock option, description			Not exceeding 25% per year
Maximum rate of stock option			25.00%
Option Expiring period			10 years
Compensation expense recognized	2,358	1,244	8,202	3,647
Unrecognized compensation cost related to nonvested common shares	8,818		8,818
Weighted average period expected to be amortized, non vested shares			1 year 4 months 24 days
Weighted-average expected volatility used			44.50%	46.30%
Weighted average grant date fair value of stock options granted			$ 27.92	$ 24.12
Total intrinsic value of options exercised	7,330	2,235	13,291	10,590
Cash received from the exercise of stock options			5,870	5,124
Tax benefit realized from tax deductions from exercises of stock options			4,127	3,192
Stock Options [Member] | Post November 2012 Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Normal retirement age			65 years
Period for options considered to be forfeited for retirees			12 months
Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period expected to be amortized, non vested shares			3 months 18 days
Expense related to nonvested common shares	222	262	667	480
Unrecognized compensation cost related to nonvested common shares	220		220
Long Term Incentive Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Periods of performance considered for calculating compensation expense			3 years
Weighted average grant date fair value			$ 69.25	$ 59.59	$ 42.12
Compensation expense charged	699	334	3,144	2,601
Cumulative amount recorded in shareholders' equity related to Long-Term Incentive Plan	6,410		6,410
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested common shares	2,069		2,069
Weighted average period expected to be amortized, non vested shares			1 year 9 months 18 days
Period for restricted shares and share units considered to be forfeited for retirees			12 months
Period for pro-rata vesting of shares or units for non-employee directors			1 year
Expense related to nonvested common shares	458	752	1,353	1,888
Common share dividends amount included in compensation cost	12	14	37	42
Employee Deferred Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common share dividends amount included in compensation cost	$ 32	$ 21	$ 90	$ 53
Percentage of base pay and annual incentive compensation deferred			100.00%
Percentage of long term incentive compensation plan deferred			90.00%