Employee Benefit Plans - Estimated Future Benefit Payments (Details)	12 Months Ended
	Dec. 31, 2019 USD ($)
Postretirement Plans
Estimated future benefit payments, net of subsidies:
2020	$ 7,300,000
2021	6,700,000
2022	6,100,000
2023	5,600,000
2024	5,000,000.0
Subsequent five years	19,300,000
Non-qualified pension plans
Employee benefit plans
Employer contributions	6,200,000
Expected minimum required funding contributions in 2019	5,600,000
United States
Employee benefit plans
Employer contributions	0
Estimated future benefit payments, net of subsidies:
2020	25,600,000
2021	25,200,000
2022	26,300,000
2023	25,900,000
2024	25,700,000
Subsequent five years	104,300,000
Foreign Plan
Employee benefit plans
Employer contributions	1,000,000.0
Expected minimum required funding contributions in 2019	1,000,000.0
Estimated future benefit payments, net of subsidies:
2020	5,000,000.0
2021	4,900,000
2022	6,000,000.0
2023	5,900,000
2024	6,200,000
Subsequent five years	$ 36,000,000.0