Defined Contribution, Bonus, and Profit Sharing Plans - Schedule of Bonus and Profit Sharing Plans Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution, Bonus, and Profit Sharing [Abstract]
Bonus and profit sharing plans expense	$ 11,455	$ 48,435	$ 15,466

Expense recognized in the period related to bonus and profit sharing plans and other awards for employee achievement.

No definition available.

Name:	itri_BonusAndProfitSharingPlansAndAwardsExpense
Namespace Prefix:	itri_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration