Employee benefit plans (Tables)

3 Months Ended

Mar. 31, 2020

Employee benefit plans

Schedule of net periodic benefit cost

The net periodic benefit cost was as follows (in thousands):

	Three Months Ended
	March 31,
	2020		2019
Service cost	$	1,457	$	1,263
Interest cost		46		84
Expected return on plan assets		(30)		(60)
Amortization of prior service cost		54		45
Amortization of actuarial losses		167		66
Net periodic benefit cost	$	1,694	$	1,398