Commitments and Contingencies (Textuals) (Details) ft² in Thousands, RUB in Thousands		12 Months Ended
	Mar. 22, 2013 USD ($) ft²	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Oct. 31, 2016 USD ($)	Oct. 31, 2016 RUB
Loss Contingencies [Line Items]
Accrued asbestos reserves		$ 8,500,000	$ 9,800,000
Number of years of lease of corporate headquarters	6 years
Area of leased office building (in square feet) | ft²	192
Purchase price of property at end of lease term	$ 41,200,000.0
Percentage of lease balance as final payment end of lease term	86.00%
Debt covenant, debt not paid when due	$ 75,000,000
Expense for known and future asbestos-related litigation		3,500,000	$ 6,300,000	$ 900,000
Maximum [Member]
Loss Contingencies [Line Items]
Accrued asbestos reserves		46,500,000
Minimum [Member]
Loss Contingencies [Line Items]
Accrued asbestos reserves		28,500,000
Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Loss Contingency, Alleged Unauthorized Payment					$ 475	RUB 30
Current Liabilities [Member]
Loss Contingencies [Line Items]
Accrued asbestos reserves		8,500,000
Other Noncurrent Liabilities [Member]
Loss Contingencies [Line Items]
Accrued asbestos reserves		$ 20,000,000