Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Earnings Per Share [Abstract]
Net income for basic calculation	$ 2,476,000	$ 7,585,000	$ 3,915,000	$ 12,810,000
Numerator for diluted calculation	$ 2,476,000	$ 7,585,000	$ 3,915,000	$ 12,810,000
Denominator for basic calculation (in shares)	16,186,000	16,241,000	16,178,000	16,229,000
Dilutive effect on shares of stock-based awards (in shares)	19,000	264,000	23,000	281,000
Denominator for diluted calculation (in shares)	16,205,000	16,505,000	16,201,000	16,510,000
Repurchases of common stock (in shares)			0	0
Weighted average performance shares outstanding during the period that are excluded from EPS Calculation	144,000	120,000	143,000	119,000
Stock options and RSUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive equity-classified stock-based awards not included in calculation of diluted earnings per share (in shares)	2,369,000	447,000	2,367,000	287,000