Commitments and Contingencies (Narrative) (Details) RUB in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Oct. 31, 2016 USD ($)	Oct. 31, 2016 RUB
Product Liability Contingency [Line Items]
Estimated repair costs	$ 5,200,000
Expense for asbestos-related litigation		$ 2,400,000	$ 1,900,000
Russia [Member]
Product Liability Contingency [Line Items]
Annual sales				$ 4,000,000
Unfavorable Regulatory Action [Member]
Product Liability Contingency [Line Items]
Alleged unauthorized payment					$ 475	RUB 30
Value of shipment					$ 68,500	RUB 62
Minimum [Member]
Product Liability Contingency [Line Items]
Probable outstanding liability for quality issue, higher range		900,000
Maximum [Member]
Product Liability Contingency [Line Items]
Probable outstanding liability for quality issue, higher range		$ 9,100,000