Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income, Balance, beginning			$ (5,035)
Other comprehensive income, before reclassifications, net of tax			(296)
Amounts reclassified from accumulated other comprehensive income, net of tax			113
Net current-period other comprehensive income, net of tax	(165)	152	(183)	321
Accumulated Other Comprehensive Income, Balance, ending	(5,218)		(5,218)
Unrealized Gain (Loss) on Marketable Securities
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income, Balance, beginning			86
Other comprehensive income, before reclassifications, net of tax			(2)
Amounts reclassified from accumulated other comprehensive income, net of tax			0
Net current-period other comprehensive income, net of tax			(2)
Accumulated Other Comprehensive Income, Balance, ending	84		84
Pension and Postretirement Health Benefits
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income, Balance, beginning			(5,608)
Other comprehensive income, before reclassifications, net of tax			0
Amounts reclassified from accumulated other comprehensive income, net of tax			113
Net current-period other comprehensive income, net of tax			113
Accumulated Other Comprehensive Income, Balance, ending	(5,495)		(5,495)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income, Balance, beginning			487
Other comprehensive income, before reclassifications, net of tax			(294)
Amounts reclassified from accumulated other comprehensive income, net of tax			0
Net current-period other comprehensive income, net of tax			(294)
Accumulated Other Comprehensive Income, Balance, ending	$ 193		$ 193