XML 85 R71.htm IDEA: XBRL DOCUMENT v3.20.2
Employee benefit plans - Periodic Benefit Cost (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Employee benefit plans          
Employer Service cost $ 1,523 $ 1,263 $ 4,457 $ 3,813  
Interest cost 49 84 142 253  
Expected return on plan assets (32) (60) (93) (180)  
Amortization of prior service cost 54 54 161 161  
Amortization of actuarial losses 166 74 500 186  
Net periodic benefit cost $ 1,760 $ 1,415 $ 5,167 $ 4,233  
Location of costs excluding the service component us-gaap:OtherNonoperatingIncomeExpense us-gaap:OtherNonoperatingIncomeExpense us-gaap:OtherNonoperatingIncomeExpense us-gaap:OtherNonoperatingIncomeExpense  
Expected contributions $ 4,000   $ 4,000    
Accrued pension obligation $ 26,200   $ 26,200   $ 24,100