Fair-Value Measurements (Schedule of Fair Value of Financial Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Derivative Asset [Abstract]
Equity securities, cost basis	$ 500
Interest Rate Swap
Derivative Liability [Abstract]
Receivable for floating rate leg	1,000	$ 15,200
Liability for fixed rate leg	13,700	20,700
Fair Value, Inputs, Level 1 \| Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	17,508	16,375
Common stock of unaffiliated foreign public company	748	839
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
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	$ (12,714)	$ (5,518)

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

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