Consolidated Condensed Schedule Of Investments (Repurchase Agreements) (Repurchase Agreements [Member], USD $) In Thousands, unless otherwise specified					12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2012 Bank Of America Securities Collateralized By Par Value $13,000 U.S. Treasury Note, Coupon 1.75%, Maturity Date 2016-05 [Member]		Dec. 31, 2011 Bank of America Securities Collateralized By Par Value $15,000 U.S. Treasury Note, Coupon 1.75%, Maturity Date 2016-05 [Member]
Schedule of Investments [Line Items]
Current Principal/Notional Amount					$ 13,650	[1],[2]	$ 15,750	[1],[2]
Securities collateralized by par value					13,000	[1],[2]	15,000	[1],[2]
U.S. treasury note, coupon					1.75%	[1],[2]	1.75%	[1],[2]
Maturity date of securities					2016-05	[1],[2]	2016-05	[1],[2]
Description					Bank of America SecuritiesCollateralized by Par Value $13,000US Treasury Note, Coupon 1.75%, Maturity Date 2016-05	[1],[2]	Bank of America SecuritiesCollateralized by Par Value $15,000US Treasury Note, Coupon 1.75%, Maturity Date 2016-05	[1],[2]
Rate					0.20%	[1],[2]	0.01%	[1],[2]
Investments maturity date					2013-01	[1],[2]	2012-01	[1],[2]
Fair value	13,650	[1],[2]	15,750	[1],[2]	13,650	[1],[2]	15,750	[1],[2]
Investment owned as a percentage of net assets	2.70%	[1],[2]	4.24%	[1],[2]
Repurchase agreements, cost	$ 13,650	[1],[2]	$ 15,750	[1],[2]

[1] In general, securities received pursuant to repurchase agreements were delivered to counterparties in short sale transactions.

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