v2.3.0.15

Debt Convertible Senior Subordinated Notes Additional Information (Details) (USD $)	9 Months Ended				3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Aug. 01, 2011 Option of the Holders [Member] Convertible Subordinated Debt [Member] Senior Subordinated Notes [Member]	Sep. 30, 2011 Option of the Company [Member] Convertible Subordinated Debt [Member] Senior Subordinated Notes [Member]	Sep. 30, 2011 2007 Senior Secured Credit Facility [Member]	Sep. 30, 2011 Convertible Subordinated Debt [Member]	Aug. 04, 2006 Convertible Subordinated Debt [Member] Senior Subordinated Notes [Member]
Convertible Senior Subordinated Notes [Line Items]
Estimated nonconvertible debt borrowing rate							7.38%
Repurchase of convertible senior subordinated debt			$ 184,800,000	$ 38,800,000
Line of credit borrowed					180,000,000
Repayments of Long-term Debt	$ 804,304,000	$ 106,524,000				$ 44,000,000

X

- Definition

Rate prepresents the entities non-convertible debt borrowing rate at the time their convertible notes were issued, which also relfects the effective interest rate on the liability component.

+ Details

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Namespace Prefix:	itri
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Amount of line of credit borrowed to pay down debt.

+ Details

Name:	itri_LineOfCreditBorrowed
Namespace Prefix:	itri
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Repurchase of convertible senior subordinated debt

+ Details

Name:	itri_RepurchaseOfConvertibleSeniorSubordinatedDebt
Namespace Prefix:	itri
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- 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.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3291-108585



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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 18

-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.



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 20

-Subparagraph b

-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.



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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