Fair-Value Measurements (Schedule of Fair Value of Financial Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Derivative Asset [Abstract]
Equity securities, cost basis	$ 500
Fair Value, Inputs, Level 1 | Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	20,665	$ 17,508
Common stock of unaffiliated foreign public company	702	748
Interest rate swaps	0	0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	0	0
Fair Value, Inputs, Level 2 | Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	0	0
Common stock of unaffiliated foreign public company	0	0
Interest rate swaps	3,328	0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	$ (5,176)	$ (12,714)