Retirement Plans - Schedule of Allocation of Plan Assets (Details)	Dec. 31, 2018	Dec. 31, 2017
United States [Member]
Actual plan asset allocations	100.00%	100.00%
United States [Member] | Short-term Investments [Member]
Actual plan asset allocations	12.00%	1.00%
United States [Member] | Fixed Income Securities [Member]
Actual plan asset allocations	27.00%	27.00%
United States [Member] | Equity Securities [Member]
Actual plan asset allocations	61.00%	72.00%
United States [Member] | Insurance Contracts [Member]
Actual plan asset allocations	0.00%	0.00%
International [Member]
Actual plan asset allocations	100.00%	100.00%
International [Member] | Short-term Investments [Member]
Actual plan asset allocations	0.00%	0.00%
International [Member] | Fixed Income Securities [Member]
Actual plan asset allocations	0.00%	0.00%
International [Member] | Equity Securities [Member]
Actual plan asset allocations	0.00%	0.00%
International [Member] | Insurance Contracts [Member]
Actual plan asset allocations	100.00%	100.00%