Retirement and Other Postretirement Benefit Plans - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Defined Benefit Retirement Plans | U.S.
Amounts recognized on the balance sheet:
Employer contribution to defined benefit retirement plans	$ 0		$ 100,000		$ 200,000
Expected employer contribution in full current year	1,100,000		1,100,000
Net amortization gain deferral	$ (100,000)		$ (300,000)	$ (200,000)
Defined Benefit Plan, Tax Status [Extensible List]	us-gaap:NonqualifiedPlanMember	us-gaap:NonqualifiedPlanMember	us-gaap:NonqualifiedPlanMember	us-gaap:NonqualifiedPlanMember	us-gaap:NonqualifiedPlanMember
Defined Benefit Retirement Plans | European
Amounts recognized on the balance sheet:
Employer contribution to defined benefit retirement plans	$ 900,000	$ 1,200,000	$ 2,800,000	$ 4,900,000	$ 6,000,000
Expected employer contribution in full current year	4,600,000		4,600,000
Net amortization gain deferral		(200,000)	(200,000)	$ (500,000)
Postretirement Health Care and Life Insurance Benefit Plans
Amounts recognized on the balance sheet:
Employer contribution to defined benefit retirement plans	100,000	$ 100,000			$ 200,000
Expected employer contribution in full current year	500,000		500,000
Net amortization gain deferral	$ 300,000		$ 900,000