Name:	us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of gain (loss) recognized in earnings, arising from liabilities measured at fair value on a recurring basis using unobservable inputs (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of purchases, sales, issues, and settlements in relation to liabilities measured at fair value on a recurring basis using unobservable inputs (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

This element represents a liability measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fair Value Measurements (Details 2) (USD $)	3 Months Ended
Fair Value Measurements (Details 2) (USD $)	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	$ 314,000	$ 2,224,000	$ 2,537,000	$ 4,300,000	$ 5,550,000	$ 5,907,000	$ 775,000
Total net unrealized (gains)/losses included in general and administrative expenses in earnings	(59,000)	(1,910,000)	(313,000)	(1,763,000)	(395,000)	(357,000)	(568,000)
Net purchases, issuances, sales and settlements					(855,000)		5,700,000
Ending balance	255,000	314,000	2,224,000	2,537,000	4,300,000	5,550,000	5,907,000
Byrne Medical Business \| Three-year price floor
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	314,000	724,000	1,037,000	1,400,000	1,795,000	2,418,000
Total net unrealized (gains)/losses included in general and administrative expenses in earnings	(59,000)	(410,000)	(313,000)	(363,000)	(395,000)	(623,000)	(582,000)
Net purchases, issuances, sales and settlements							3,000,000
Ending balance	255,000	314,000	724,000	1,037,000	1,400,000	1,795,000	2,418,000
Contingent consideration liability \| ConFirm Monitoring Business
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance					855,000	689,000	775,000
Total net unrealized (gains)/losses included in general and administrative expenses in earnings						166,000	(86,000)
Net purchases, issuances, sales and settlements					(855,000)
Ending balance						855,000	689,000
Contingent consideration liability \| Byrne Medical Business
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance		1,500,000		2,900,000		2,800,000
Total net unrealized (gains)/losses included in general and administrative expenses in earnings		(1,500,000)		(1,400,000)		100,000	100,000
Net purchases, issuances, sales and settlements							2,700,000
Ending balance				$ 1,500,000		$ 2,900,000	$ 2,800,000