Consolidated Condensed Schedule of Investments (Cash Equivalents) - Cash equivalents shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) shares	[2]
Schedule of Investments [Line Items]
Investment owned as a percentage of equity	2.09%	[1]
Money Market Funds, at Cost	$ 12,460
Money Market Funds, at Carrying Value	$ 12,460
Various Money Market Funds [Member]
Schedule of Investments [Line Items]
Investment Owned, Balance, Shares | shares	12,460
Money Market Funds, at Carrying Value	$ 12,460
Various Money Market Funds [Member] | Minimum
Schedule of Investments [Line Items]
Rate	2.31%
Various Money Market Funds [Member] | Maximum
Schedule of Investments [Line Items]
Rate	2.34%

[1] Classification percentages are based on Total Equity.

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