Income Taxes (Schedule of Components of Deferred Income Tax Expense/(Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Net effect of temporary differences	$ 5,262	$ (18)	$ (4,657)
Foreign tax credits	7,173	12,530	9,437
Retirement benefits	401	(752)	2,360
Net impact to operating loss carryforwards	(1,532)	1,314	1,046
Enacted changes in tax laws and rates		(112)	2,067
Adjustment to beginning-of-the-year valuation allowance balance for changes in circumstances	168	(525)	(4,882)
Deferred income tax provision	$ 11,472	$ 12,437	$ 5,371