Postretirement Benefit Plans - Change in Benefit Obligation, Plan Assets, Funded Status, and Balance Sheet Items (Details) - Postretirement Benefit Plans [Member] - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Discount rate		3.57%	3.97%
Discount rate	3.43%	4.30%	3.57%	3.97%
Expected long-term return on plan assets	4.85%	4.50%	6.00%
Change in benefit obligation:
Benefit obligation at beginning of year	$ 186,900,000	$ 219,800,000
Service cost	200,000	200,000	$ 100,000
Interest cost	5,900,000	7,600,000	9,100,000
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	92,800,000	4,400,000
International plan exchange rate change	(14,400,000)	(20,700,000)
International plan exchange rate change	200,000	(100,000)
Defined Benefit Plan, Plan Assets, Benefits Paid	22,700,000	27,200,000
Benefit obligation at end of year	63,400,000	186,900,000	$ 219,800,000
Defined Benefit Plan, Benefit Obligation, Business Combination	$ 100,000	$ 11,700,000