XML 63 R47.htm IDEA: XBRL DOCUMENT
v3.20.4

Summary of Significant Accounting Policies - Basis of Consolidation Policy Additional Information (Details) | 12 Months Ended
--- | ---
Dec. 31, 2020
Maximum [Member] |
Basis of Consolidation [Abstract] |
Ownership interest to use equity method | 50.00%
Ownership interest to use cost method | 20.00%
Minimum [Member] |
Basis of Consolidation [Abstract] |
Ownership interest to be held for consolidation | 50.00%
Ownership interest to use equity method | 20.00%

X
- Definition Basis of Consolidation [Abstract] + References No definition available. + Details
Name: | itri_BasisofConsolidationAbstract
Namespace Prefix: | itri_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ownership Interest to be Held for Consolidation + References No definition available. + Details
Name: | itri_OwnershipInterestToBeHeldForConsolidation
Namespace Prefix: | itri_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Entities in which the company has less than 20% investment and where they do not excercise significant influence are accounted for under the cost method. + References No definition available. + Details
Name: | itri_OwnershipInterestToUseCostMethod
Namespace Prefix: | itri_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |