Income Taxes (Schedule of Components of Deferred Income Tax Expense/(Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net effect of temporary differences	$ (18)	$ (4,657)	$ (5,774)
Foreign tax credits	12,530	9,437	8,340
Retirement benefits	(752)	2,360	(502)
Net impact to operating loss carryforwards	1,314	1,046	(900)
Enacted changes in tax laws and rates	(112)	2,067	1,878
Adjustment to beginning-of-the-year valuation allowance balance for changes in circumstances	(525)	(4,882)	(3,522)
Deferred income tax provision	$ 12,437	$ 5,371	$ (480)