Consolidated Condensed Schedule Of Investments Consolidated Condensed Schedule of Investments (Cash Equivalents) - Cash Equivalents [Member] - USD ($) shares in Thousands, $ in Thousands		6 Months Ended		12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017
Schedule of Investments [Line Items]
Money Market Funds, at Carrying Value		$ 6,833	[1]	$ 26,500	[2]
Money Market Funds, at Cost		$ 6,833	[1]	$ 26,500	[2]
Investment owned as a percentage of equity		1.11%	[1],[3]	4.27%	[2],[4]
Various Money Market Funds [Member]
Schedule of Investments [Line Items]
Money Market Funds, at Carrying Value		$ 6,833	[1]	$ 26,500	[2]
Investment Owned, Balance, Shares		6,833	[1]	26,500	[2]
Rate	[2]			1.17%
Various Money Market Funds [Member] | Minimum [Member]
Schedule of Investments [Line Items]
Rate	[1]	1.80%
Various Money Market Funds [Member] | Maximum [Member]
Schedule of Investments [Line Items]
Rate	[1]	1.81%

[1] See Note 2 and Note 3 in Notes to Consolidated Financial Statements.

[2] See Note 2 and Note 3 in Notes to Consolidated Financial Statements.

[3] Classification percentages are based on Total Equity.

[4] Classification percentages are based on Total Equity.