Represents the number of customers contributing to a percentage of the net sales revenue of the segment.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611

+ Details

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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- Details

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- Details

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- Details

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Information as to Operating Segments and Foreign and Domestic Operations - Concentration Risk (Details)	3 Months Ended								12 Months Ended
	Jul. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Jan. 31, 2016 USD ($)	Oct. 31, 2015 USD ($)	Jul. 31, 2015 USD ($)	Apr. 30, 2015 USD ($)	Jan. 31, 2015 USD ($)	Oct. 31, 2014 USD ($)	Jul. 31, 2016 USD ($) item	Jul. 31, 2015 USD ($)	Jul. 31, 2014 USD ($)
Concentration risk
Consolidated net sales	$ 179,002,000	$ 173,703,000	$ 158,271,000	$ 153,779,000	$ 151,255,000	$ 141,508,000	$ 135,430,000	$ 136,811,000	$ 664,755,000	$ 565,004,000	$ 488,749,000
Water Purification and Filtration
Concentration risk
Consolidated net sales									177,669,000	173,834,000	159,505,000
Healthcare Disposables
Concentration risk
Consolidated net sales									112,584,000	106,920,000	101,809,000
Dialysis
Concentration risk
Consolidated net sales									$ 32,750,000	$ 31,240,000	$ 30,926,000
Customer concentration \| Segment sales \| Water Purification and Filtration \| Two customers
Concentration risk
Number of customers accounting for a percentage of segment net sales \| item									2
Concentration risk within segment (as a percent)									43.70%
Customer concentration \| Segment sales \| Healthcare Disposables \| Four customers
Concentration risk
Number of customers accounting for a percentage of segment net sales \| item									4
Concentration risk within segment (as a percent)									49.10%
Customer concentration \| Segment sales \| Dialysis \| Fresenius and DaVita
Concentration risk
Concentration risk within segment (as a percent)									42.60%
Customer concentration \| Net sales \| Da Vita Inc
Concentration risk
Concentration risk within segment (as a percent)											10.00%
Consolidated net sales											$ 48,620,000