Fair-Value Measurements (Schedule of Fair Value of Financial Assets and Liabilities) (Details) - USD ($) $ in Thousands		Sep. 30, 2019		Dec. 31, 2018
Derivative asset:
Common stock of foreign public company, original cost		$ 5		$ 5
Interest Rate Current Swap [Member]
Derivative asset:
Liability for fixed rate leg		155		320
Receivable for floating rate leg		225		275
Quoted Prices in Active Markets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Cash equivalents		26,317		14,234
Common stock of unaffiliated foreign public company	[1]	839		731
Liabilities:
Interest rate swaps
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Cash equivalents
Common stock of unaffiliated foreign public company	[1]
Liabilities:
Interest rate swaps		$ (7,021)	[2]	$ 4,548	[3]

[1] Original cost basis $0.5 million.

[2] Net of $15.5 million receivable floating leg and $22.5 million liability fixed leg.

[3] Net of $32.0 million receivable floating leg and $27.5 million liability fixed leg.