Stock-Based Compensation (Details) (USD $)	3 Months Ended		12 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Jul. 31, 2011
Stock-based compensation expense before income tax benefit	$ 873,000	$ 1,508,000
Income tax benefit	(306,000)	(542,000)
Net stock-based compensation expense	567,000	966,000
Total stock-based compensation expense related to employee stock purchase plan	61,000	69,000
Required fair value remeasurement of liability-classified stock appreciation rights	20,000	17,000
Stock-based compensation capitalized and included in ending inventory	117,000		117,000
Per share weighted average grant date fair value of stock based awards granted	$ 5.88	$ 6.67
Expected dividend yield	4.04%	3.66%
Expected volatility	36.00%	38.00%
Risk free interest rate	0.88%	1.27%
Expected life (in years)	5.42	5.18
Contractual term on stock-based awards granted	five or ten years
Vesting period on stock-based awards granted	three or five years
Accrued expense related to the cash settlement of liability-classified stock appreciation rights	42,000		22,000
Targeted annual dividend per share	$ 1.10	$ 1.00
Actual income tax benefit recorded for the tax deductions relating to the exercise of stock based awards	120,000	25,000
Less: Tax benefit initially recognized on exercised stock-based awards vesting subsequent to the adoption of accounting standards that require us to expense stock-based awards, excluding income tax shortfalls	(99,000)	(28,000)
Excess income tax benefit (shortfall) recorded as an increase (decrease) to additional paid-in capital	21,000	(3,000)
Less: Tax benefit initially disclosed but not previously recognized on exercised equity-classified stock-based awards vesting prior to the adoption of accounting standards that require us to expense stock-based awards	(2,000)	0
Excess income tax benefits (shortfall) from exercised equity-classified stock-based awards reported as a cash flow from financing activities in our Condensed Consolidated Statements of Cash Flows	19,000	(3,000)
Total remaining unrecognized compensation cost related to the unvested stock-based awards	8,673,000
Estimated forfeitures related to unvested stock-based awards	530,000
Weighted average number of years net compensation cost is expected to be recognized over	3.7
Hypothetical tax benefits related to stock-based awards	22,973,000
Reduction to APIC due to reversal of unrealized deferred tax assets associated with certain vested equity-classified expired and unexercised stock-based awards	1,021,000	1,033,000
Cost of Sales [Member]
Stock-based compensation expense before income tax benefit	53,000	122,000
Selling, General and Administrative Expenses [Member]
Stock-based compensation expense before income tax benefit	645,000	1,098,000
Research and Development Expenses [Member]
Stock-based compensation expense before income tax benefit	$ 175,000	$ 288,000