Employee Benefit Plans - FVM (Details) - Pensions - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	$ 16,487	$ 15,130	$ 3,993
Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	8,619	8,447
Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	7,868	6,683
Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	0	0
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	13,038	11,458
Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	5,170	4,775
Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	7,868	6,683
Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	0	0
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	3,449	3,672
Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	3,449	3,672
Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	0	0
Cash and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	$ 0	$ 0