Pension, Post-Retirement and Post-Employment Plans - Expected Future Benefit Payments (Details)	Dec. 31, 2020 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans
2021	$ 14,700,000
2022	15,400,000
2023	14,800,000
2024	15,100,000
2025	15,000,000.0
Subsequent five years	73,600,000
Total	148,600,000
Company's expected future contribution to the plan	0
Pension and SERP Benefits | Domestic
Defined Benefit Plans and Other Postretirement Benefit Plans
2021	12,800,000
2022	13,700,000
2023	13,000,000.0
2024	12,900,000
2025	13,300,000
Subsequent five years	64,100,000
Total	129,800,000
Pension and SERP Benefits | Foreign
Defined Benefit Plans and Other Postretirement Benefit Plans
2021	1,400,000
2022	1,200,000
2023	1,300,000
2024	1,700,000
2025	1,200,000
Subsequent five years	7,200,000
Total	14,000,000.0
Post-retirement Medical Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans
2021	500,000
2022	500,000
2023	500,000
2024	500,000
2025	500,000
Subsequent five years	2,300,000
Total	$ 4,800,000