Stock-Based Compensation Plans (Details)	3 Months Ended	12 Months Ended
	Jan. 31, 2014 shares	Jul. 31, 2015 USD ($) Plan $ / shares shares	Jul. 31, 2014 USD ($) $ / shares shares	Jul. 31, 2013 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sales Goal | $		$ 100,000,000
Assumptions used to derive weighted average fair value of options granted [Abstract]
Term of U.S. Treasury yield curve used to estimate average risk-free interest rate		10 years
Future compensation cost expected to be recognized [Abstract]
Fiscal 2016 | $		$ 904,000
Fiscal 2017 | $		605,000
Fiscal 2018 | $		411,000
Fiscal 2019 | $		82,000
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $		929,000	$ 1,008,000	$ 931,000
Income Tax benefits from Share-based Compensation | $		$ 238,000	331,000	$ 285,000
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options outstanding (in shares)		1,088,540
Options outstanding, weighted average remaining contractual life		6 years 9 months 18 days
Number of exercisable options (in shares)		624,455
Exercisable options, weighted average remaining contractual life		5 years 3 months 18 days
Facility Closing [Member]
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $			$ 201,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term		10 years
Options, number of shares [Roll Forward]
Options outstanding, beginning of period (in shares)		815,162	747,662	679,745
Granted (in shares)	300,000	353,000	117,500	142,227
Forfeited (in shares)		(57,122)	0	(15,000)
Exercised (in shares)		(22,500)	(50,000)	(59,310)
Options outstanding, end of period (in shares)		1,088,540	815,162	747,662
Options exercisable, end of period (in shares)		624,455
Options, weighted average exercise price [Roll Forward]
Options outstanding, beginning of period (in dollars per share) | $ / shares		$ 4.25	$ 3.23	$ 3.80
Granted (in dollars per share) | $ / shares		3.49	3.64	4.52
Forfeited (in dollars per share) | $ / shares		5.38	0	4.54
Exercised (in dollars per share) | $ / shares		1.27	1.17	1.10
Options outstanding, end of period (in dollars per share) | $ / shares		4.00	$ 4.25	$ 3.23
Options exercisable, end of period (in dollars per share) | $ / shares		$ 4.06
Unvested options, number of shares [Roll Forward]
Unvested options, beginning of period (in shares)		232,863
Granted (in shares)	300,000	353,000	117,500	142,227
Vested (in shares)		(121,778)
Unvested options, period end (in shares)		464,085	232,863
Unvested options, weighted average grant date value [Roll Forward]
Unvested options, beginning of period (in dollars per share) | $ / shares		$ 3.50
Granted (in dollars per share) | $ / shares		2.56
Vested (in dollars per share) | $ / shares		2.92
Unvested options, period end (in dollars per share) | $ / shares		$ 2.91	$ 3.50
Proceeds, related tax benefits and intrinsic value of options exercised [Abstract]
Proceeds of options exercised | $		$ 29,000	$ 59,000	$ 65,000
Related tax benefit recognized | $		16,000	38,000	72,000
Intrinsic value of options exercised | $		23,000	$ 48,000	$ 56,000
Additional information about options outstanding [Abstract]
Aggregate intrinsic value | $		$ 3,312,000
Weighted average contractual term		6 years 9 months 18 days
Additional information about exercisable options [Abstract]
Aggregate intrinsic value | $		$ 1,959,000
Weighted average contractual term		5 years 3 months 18 days
Assumptions used to derive weighted average fair value of options granted [Abstract]
Expected average risk-free interest rate (in hundredths)			2.90%	1.72%
Expected average life		10 years	10 years	10 years
Expected volatility (in hundredths)		65.70%	68.60%	70.50%
Expected dividend yield (in hundredths)		0.00%	0.00%	0.00%
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $		$ 513,000	$ 527,000	$ 463,000
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Assumptions used to derive weighted average fair value of options granted [Abstract]
Expected average risk-free interest rate (in hundredths)		2.10%
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		5 years
Assumptions used to derive weighted average fair value of options granted [Abstract]
Expected average risk-free interest rate (in hundredths)		2.19%
Stock Options [Member] | Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		12 months
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $		$ 133,000	163,000	230,000
Stock Options [Member] | Employees [Member]
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $		$ 380,000	$ 364,000	$ 233,000
Restricted Stock [Member]
Restricted stock grants, number of shares [Roll Forward]
Restricted stock awards, beginning of period (in shares)		275,547	405,248	431,778
Granted (in shares)	200,000	208,000	7,000	70,307
Forfeited (in shares)		(4,334)	(2,335)	(10,160)
Vested (in shares)		(189,399)	(134,366)	(86,677)
End of period (in shares)		289,814	275,547	405,248
Weighted Average Grant Date Fair Value [Roll Forward]
Restricted stock awards, beginning of period (in dollars per share) | $ / shares		$ 3.42	$ 3.79	$ 3.82
Granted (in dollars per share) | $ / shares		3.43	3.38	4.52
Forfeited (in dollars per share) | $ / shares		4.27	3.88	3.47
Vested (in dollars per share) | $ / shares		2.47	4.52	4.57
End of period (in dollars per share) | $ / shares		$ 4.04	$ 3.42	$ 3.79
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $		$ 416,000	$ 481,000	$ 468,000
Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		5 years
Restricted Stock [Member] | Employees [Member]
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $		$ 361,000	426,000	413,000
Restricted Stock [Member] | Advisors [Member]
Compensation expense associated with stock-based compensation plans [Abstract]
Compensation Expense | $		$ 55,000	$ 55,000	$ 55,000
2001 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of existing active option plans prior to merger | Plan		2
Number of terminated option plans prior to merger | Plan		2
Shares authorized (in shares)		2,000,000
Aggregate number of available for future grant (in shares)		167,427
2001 Stock Plan [Member] | Advisors [Member]
Restricted stock grants, number of shares [Roll Forward]
Granted (in shares)		13,958
2001 Stock Plan [Member] | Restricted Stock [Member]
Assumptions used to derive weighted average fair value of options granted [Abstract]
Unrecognized compensation cost related to non-vested share-based compensation arrangements granted | $		$ 2,000,000
2005 Non-Employee Directors' Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)		700,000
Aggregate number of available for future grant (in shares)		260,000
Less than 2.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit (in dollars per share) | $ / shares		$ 2.00
Number of options outstanding (in shares)		102,083
Options outstanding, weighted average remaining contractual life		4 years
Number of exercisable options (in shares)		102,083
Exercisable options, weighted average remaining contractual life		4 years
2.01 to 3.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share) | $ / shares		$ 2.01
Exercise price range, upper range limit (in dollars per share) | $ / shares		$ 3.00
Number of options outstanding (in shares)		40,000
Options outstanding, weighted average remaining contractual life		2 years 3 months 18 days
Number of exercisable options (in shares)		40,000
Exercisable options, weighted average remaining contractual life		2 years 3 months 18 days
3.01 to 4.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share) | $ / shares		$ 3.01
Exercise price range, upper range limit (in dollars per share) | $ / shares		$ 4.00
Number of options outstanding (in shares)		497,500
Options outstanding, weighted average remaining contractual life		8 years 6 months
Number of exercisable options (in shares)		144,377
Exercisable options, weighted average remaining contractual life		6 years 8 months 12 days
4.01 to 5.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share) | $ / shares		$ 4.01
Exercise price range, upper range limit (in dollars per share) | $ / shares		$ 5.00
Number of options outstanding (in shares)		229,813
Options outstanding, weighted average remaining contractual life		5 years 8 months 12 days
Number of exercisable options (in shares)		186,307
Exercisable options, weighted average remaining contractual life		5 years 4 months 24 days
5.01 to 6.21 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share) | $ / shares		$ 5.01
Exercise price range, upper range limit (in dollars per share) | $ / shares		$ 6.21
Number of options outstanding (in shares)		219,144
Options outstanding, weighted average remaining contractual life		6 years
Number of exercisable options (in shares)		151,689
Exercisable options, weighted average remaining contractual life		5 years 6 months