Defined Benefit Pension Plans - Schedule of Net Periodic Pension Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Service cost	$ 3,711	$ 4,034	$ 3,968
Interest cost	2,278	2,324	2,264
Expected return on plan assets	(608)	(670)	(594)
Amortization of prior service costs	68	61	62
Amortization of actuarial net loss	1,648	1,533	2,308
Settlement	250	1	(2)
Curtailment	0	1	(586)
Net periodic benefit cost	$ 7,347	$ 7,284	$ 7,420