Income Taxes (Narrative) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Line Items]
Income tax impact associated with stock option exercises		$ 0	$ 2,454,000	$ (2,233,000)
Other Comprehensive Income (Loss), Tax		394,000	(285,000)	21,000
Valuation Allowance	[1]	5,182,000	4,594,000
Valuation Allowance, Net of Federal Tax		4,100,000	3,000,000
Tax Cuts and Jobs Act of 2017, Provisional Income Tax Expense (Benefit)		48,300,000
Tax Cuts and Jobs Act of 2017, Provisional Income Tax Expense (Benefit) related to remeasurement of DTA, DTL		26,600,000
Tax Cuts and Jobs Act of 2017, Provisional Income Tax Expense (Benefit) deemed repatriation of foreign earnings		21,700,000
Possible reduction in liabilities for uncertain tax positions		900,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		10,400,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense		(400,000)	600,000	$ 100,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		3,300,000	3,600,000
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount		175,000,000	154,200,000
State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Valuation Allowance		5,200,000	$ 4,600,000
Tax Credit Carryforwards		3,100,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		600,000
US Federal [Member]
Income Tax Disclosure [Line Items]
Operating Loss Carryforwards		$ 15,800,000
Operating Loss Carryforwards Expiration Year		2021
ITALY | Earliest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2004
ITALY | Latest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2012
GERMANY | Earliest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2008
GERMANY | Latest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2013
UNITED KINGDOM | Earliest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2014
UNITED KINGDOM | Latest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2016
FRANCE | Earliest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2015
FRANCE | Latest Tax Year [Member]
Income Tax Disclosure [Line Items]
Income Tax Examination, Year under Examination		2016

[1] Valuation allowance is presented gross. The valuation allowance net of the federal tax effect is $4.1 million and $3.0 million for the years ended December 31, 2017 and 2016, respectively.