Annual report pursuant to Section 13 and 15(d)

Employee Benefit Obligation - Additional Information (Details)

v3.20.4
Employee Benefit Obligation - Additional Information (Details)
12 Months Ended
Dec. 31, 2020
USD ($)
BenefitPlan
Dec. 31, 2019
USD ($)
Compensation And Retirement Disclosure [Abstract]    
Number of defined benefit plans | BenefitPlan 2  
Total costs of defined benefit plans $ 465,000 $ 287,000
Plan assets servicing the defined benefit plan $ 0  
Defined Contribution Plan, Plan Name [Extensible List] klr:FourZeroOneKDefinedContributionPlanMember  
Defined Contribution Plan, Sponsor Location [Extensible List] us-gaap:DomesticPlanMember  
Contributions for 401 (k) plan $ 102,000 $ 54,000