v2.4.1.9

Restructuring Restructuring Expected Costs, Cost Recognized, and Remaining Costs to be Recognized - 2014 Projects (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 50,857us-gaap_RestructuringCharges	$ 35,497us-gaap_RestructuringCharges	$ 1,665us-gaap_RestructuringCharges
Employee severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	41,952us-gaap_RestructuringCharges / us-gaap_RestructuringCostAndReserveAxis = us-gaap_EmployeeSeveranceMember
Asset Impairment and Net (Gain) Loss on Sale or Disposal [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	5,220us-gaap_RestructuringCharges / us-gaap_RestructuringCostAndReserveAxis = itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember
Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	3,685us-gaap_RestructuringCharges / us-gaap_RestructuringCostAndReserveAxis = us-gaap_OtherRestructuringMember
2014 Project [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	66,653us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring Charges	55,800us-gaap_RestructuringCharges / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring and Related Cost, Expected Cost Remaining	10,853us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
2014 Project [Member] | Electricity Operating Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	39,730us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember
Restructuring Charges	29,660us-gaap_RestructuringCharges / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember
Restructuring and Related Cost, Expected Cost Remaining	10,070us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember
2014 Project [Member] | Gas Operating Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	12,455us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_GasOperatingSegmentMember
Restructuring Charges	12,185us-gaap_RestructuringCharges / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_GasOperatingSegmentMember
Restructuring and Related Cost, Expected Cost Remaining	270us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_GasOperatingSegmentMember
2014 Project [Member] | Water Operating Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	1,145us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_WaterOperatingSegmentMember
Restructuring Charges	1,106us-gaap_RestructuringCharges / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_WaterOperatingSegmentMember
Restructuring and Related Cost, Expected Cost Remaining	39us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = itri_WaterOperatingSegmentMember
2014 Project [Member] | Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	13,323us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateNonSegmentMember
Restructuring Charges	12,849us-gaap_RestructuringCharges / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateNonSegmentMember
Restructuring and Related Cost, Expected Cost Remaining	474us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateNonSegmentMember
2014 Project [Member] | Employee severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	47,447us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringCostAndReserveAxis = us-gaap_EmployeeSeveranceMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring Charges	47,447us-gaap_RestructuringCharges / us-gaap_RestructuringCostAndReserveAxis = us-gaap_EmployeeSeveranceMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring and Related Cost, Expected Cost Remaining	0us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringCostAndReserveAxis = us-gaap_EmployeeSeveranceMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
2014 Project [Member] | Asset Impairment and Net (Gain) Loss on Sale or Disposal [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	7,952us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringCostAndReserveAxis = itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring Charges	7,952us-gaap_RestructuringCharges / us-gaap_RestructuringCostAndReserveAxis = itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring and Related Cost, Expected Cost Remaining	0us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringCostAndReserveAxis = itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
2014 Project [Member] | Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	11,254us-gaap_RestructuringAndRelatedCostExpectedCost1 / us-gaap_RestructuringCostAndReserveAxis = us-gaap_OtherRestructuringMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring Charges	401us-gaap_RestructuringCharges / us-gaap_RestructuringCostAndReserveAxis = us-gaap_OtherRestructuringMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember
Restructuring and Related Cost, Expected Cost Remaining	$ 10,853us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1 / us-gaap_RestructuringCostAndReserveAxis = us-gaap_OtherRestructuringMember / us-gaap_RestructuringPlanAxis = itri_A2014ProjectMember

X

- Definition

Amount expected to be recognized in earnings for the specified restructuring cost.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869



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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB Topic 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringAndRelatedCostExpectedCost1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of expected cost remaining for the specified restructuring cost.

+ References

No definition available.

+ Details

Name:	us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 5.P.3)

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747



Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

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

X

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_OtherRestructuringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RestructuringPlanAxis=itri_A2014ProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: