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Employee Benefit Plans - Badger Meter Employee Savings and Stock Ownership Plan (ESSOP) - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]      
Pretax income allowed to be deferred (as a percent) 20.00%    
Company match (as a percent) 25.00%    
Maximum match of employee's salary (as a percent) 7.00%    
Compensation expense $ 0.5 $ 0.6 $ 0.5
Defined Contribution Feature      
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]      
Compensation expense $ 2.0 $ 3.1 $ 3.0