Retirement Plans - Components of Prepaid (Accrued) Cost (Details 3) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Retirement Plans
Prepaid pension asset	$ 54,100	$ 57,050
Post-Retirement Life Insurance Plan
Retirement Plans
Accrued expenses and other liabilities	(407)	(418)
Long-term pension obligations	(4,188)	(4,716)
Components of prepaid (accrued) cost, net	(4,595)	(5,134)
Domestic Plan [Member]
Retirement Plans
Prepaid pension asset	54,100	57,050
Accrued expenses and other liabilities	(100)	(100)
Long-term pension obligations	(992)	(1,122)
Components of prepaid (accrued) cost, net	53,008	55,828
Foreign Plan [Member]
Retirement Plans
Prepaid pension asset	0	0
Accrued expenses and other liabilities	0	0
Long-term pension obligations	(1,331)	(1,363)
Components of prepaid (accrued) cost, net	$ (1,331)	$ (1,363)