Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets, Net	$ 26,919	$ 35,150
Undistributed Earnings of Foreign Subsidiaries	300,000
Income Tax Reconciliation Change In Enacted Tax Rate	$ 18,388	$ 0	$ 0
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate	35.00%
Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate	21.00%
U.S. Tax Reform Act	On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (“U.S. Tax Reform”). U.S. Tax Reform includes multiple changes to the U.S. tax code with varying effects on the Company’s 2017 results, including, but not limited to, (i) a revaluation of the Company’s domestic deferred tax assets and liabilities based upon the reduction of the U.S. federal statutory corporate income tax rate from 35% to 21% and (ii) implementing a new system of taxation for non-U.S. earnings which eliminates U.S. federal income taxes on dividends from certain foreign subsidiaries and imposes a one-time transition tax on the deemed repatriation of undistributed earnings of certain foreign subsidiaries that is payable over eight years. U.S. Tax Reform also makes changes to the U.S. tax code that will affect 2018 and future years, including, but not limited to, (i) reduction of the U.S. federal statutory corporate tax rate; (ii) elimination of the corporate alternative minimum tax; (iii) the creation of the base erosion anti-abuse tax, a new minimum tax; (iv) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries; (v) a new provision designed to tax global intangible low-taxed income (“GILTI”), which allows for the possibility of using foreign tax credits (“FTCs”) and a deduction of up to 50 percent to offset the income tax liability (subject to some limitations); (vi) a new limitation on deductible interest expense; (vii) the repeal of the domestic production activity deduction; (viii) limitations on the deductibility of certain executive compensation; (ix) limitations on the use of FTCs to reduce the U.S. income tax liability; (x) a reduction in the dividends received deduction from 70% to 50% (in the case of less-than-20%-owned subsidiaries), and from 80% to 65% (in the case of less-than-80%-owned subsidiaries); and (xi) limitations on net operating losses (“NOLs”) generated after December 31, 2017, to 80 percent of taxable income. The SEC staff issued guidance on accounting for the tax effects of U.S. Tax Reform and provided a one-year measurement period for companies to complete the accounting. Companies are required to reflect the income tax effects of those aspects of U.S. Tax Reform for which the accounting is complete. To the extent that a company’s accounting for certain income tax effects of U.S. Tax Reform are incomplete but the company is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to use the applicable accounting guidance on the basis of the provisions of the tax laws that were in effect immediately before the enactment of U.S. Tax Reform. In connection with the Company’s initial analysis of the impact of U.S. Tax Reform, the Company has recorded incremental tax expense of $22.2 million for the year ended December 31, 2017, which includes deferred tax expense of approximately $4.5 million and current tax expense of approximately $17.8 million, net of the impact of eliminating U.S. federal income taxes on dividends from certain foreign subsidiaries in the current year, the details of which are described below. The Company has made reasonable interpretations and assumptions with regard to various uncertainties and ambiguities in the application of certain provisions of U.S. Tax Reform. It is possible that the Internal Revenue Service (“IRS”) could issue subsequent guidance or take positions on audit that differ from the Company’s interpretations and assumptions. The Company currently believes subsequent guidance issued or interpretations made by the IRS will not be materially different from the Company’s application of the provisions of U.S. Tax Reform. U.S. Tax Reform reduced the U.S. federal statutory corporate tax rate from 35% to 21%, effective January 1, 2018. Consequently, the Company has recorded a decrease in domestic net deferred tax assets of approximately $4.5 million with a corresponding net adjustment to deferred income tax expense for the year ended December 31, 2017. The deemed repatriation transition tax (“Transition Tax”) is a tax on previously untaxed accumulated and current earnings and profits (“E&P”) of certain of the Company’s foreign subsidiaries. To determine the amount of the Transition Tax, the Company must determine, in addition to other factors, the amount of E&P of its relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings after 1986. The Company made a reasonable estimate of its Transition Tax and recorded a gross provisional Transition Tax obligation of $18.4 million in its December 31, 2017 financial statements. The Company will elect to pay its Transition Tax in installments over eight years as provided for in U.S. Tax Reform.
Domestic Country [Member]
Deferred Tax Assets, Net	$ 300
Foreign Tax Authority [Member]
Operating Loss Carryforwards	8,900
Operating Loss Carryforwards, Valuation Allowance	800
Foreign Tax Authority [Member] | Expiration In Next Year [Member]
Operating Loss Carryforwards	200
Foreign Tax Authority [Member] | Expiration In Year Two [Member]
Operating Loss Carryforwards	300
Foreign Tax Authority [Member] | Expiration In Year Three [Member]
Operating Loss Carryforwards	100
Foreign Tax Authority [Member] | Expiration In Year Four [Member]
Operating Loss Carryforwards	200
Foreign Tax Authority [Member] | Expiration In Year Five [Member]
Operating Loss Carryforwards	100
Foreign Tax Authority [Member] | Expiration In Year Six [Member]
Operating Loss Carryforwards	$ 800