Information By Segment (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenues	$ 509,594	$ 635,037	$ 1,108,009	$ 1,249,613
Gross profit	138,517	191,214	310,083	378,477
Operating income (loss)	(45,387)	43,558	(19,017)	64,381
Total other income (expense)	(12,299)	(15,022)	(21,957)	(29,873)
Income (loss) before income taxes	(57,686)	28,536	(40,974)	34,508
Device Solutions [Member]
Segment Reporting Information [Line Items]
Revenues	129,165	217,723	331,444	439,478
Gross profit	11,948	41,590	44,315	81,506
Operating income (loss)	(1,120)	28,355	17,078	53,812
Networked Solutions Segment [Member]
Segment Reporting Information [Line Items]
Revenues	324,480	355,916	665,325	692,343
Gross profit	108,323	126,243	230,073	253,311
Operating income (loss)	77,382	98,035	166,062	193,357
Outcomes Segment [Member]
Segment Reporting Information [Line Items]
Revenues	55,949	61,398	111,240	117,792
Gross profit	18,246	23,381	35,695	43,660
Operating income (loss)	9,226	14,367	17,424	24,777
Corporate Unallocated [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(130,875)	(97,199)	(219,581)	(207,565)
Product [Member]
Segment Reporting Information [Line Items]
Revenues	438,985	566,047	967,122	1,110,897
Product [Member] \| Device Solutions [Member]
Segment Reporting Information [Line Items]
Revenues	126,950	214,589	327,118	433,158
Product [Member] \| Networked Solutions Segment [Member]
Segment Reporting Information [Line Items]
Revenues	300,351	333,422	615,788	647,772
Product [Member] \| Outcomes Segment [Member]
Segment Reporting Information [Line Items]
Revenues	11,684	18,036	24,216	29,967
Service [Member]
Segment Reporting Information [Line Items]
Revenues	70,609	68,990	140,887	138,716
Service [Member] \| Device Solutions [Member]
Segment Reporting Information [Line Items]
Revenues	2,215	3,134	4,326	6,320
Service [Member] \| Networked Solutions Segment [Member]
Segment Reporting Information [Line Items]
Revenues	24,129	22,494	49,537	44,571
Service [Member] \| Outcomes Segment [Member]
Segment Reporting Information [Line Items]
Revenues	$ 44,265	$ 43,362	$ 87,024	$ 87,825

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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

- Definition

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

- Definition

The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

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

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

+ Details

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

- 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

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=itri_DeviceSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=itri_NetworkedSolutionsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=itri_OutcomesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=us-gaap_ProductMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=us-gaap_ServiceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: