Income Taxes - Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income Tax Provision at the Federal Statutory Tax Rate	$ 29,403	$ 24,578	$ 27,402
Differences in Tax Rates on Foreign Earnings and Remittances	(2,862)	(5,097)	(3,025)
Foreign Dividends	2,939	2,690	3,278
Excess Foreign Tax Credit Utilization	(5,493)	(4,141)	(5,011)
Research and Development Activities Credit Utilization	(238)	(245)	(226)
Uncertain Tax Positions	(833)	226	263
Domestic Production Activities Deduction	(875)	(910)	(567)
State Income Tax Provisions, Net	357	133	517
Non-deductible Entertainment and Business Meals Expense	238	249	278
Miscellaneous Items, Net	590	302	630
Income Tax Expense (Benefit), Total	$ 23,226	$ 17,785	$ 23,539