2. Significant Accounting Policies: Fair Value Measurement and Disclosures, Policy: Fair Value, Assets Measured on Recurring Basis (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Fair Value of Assets, Exchange Traded Futures Contracts	$ 102,690	$ 221,007
Fair Value of Assets, Fund's Investments	102,690	2,220,912
Fair Value of Assets, U.S. Treasury Bills		1,999,905
Fair Value, Inputs, Level 1
Fair Value of Assets, Exchange Traded Futures Contracts	102,690	221,007
Fair Value of Assets, Fund's Investments	102,690	221,007
Fair Value, Inputs, Level 2
Fair Value of Assets, Fund's Investments		1,999,905
Fair Value of Assets, U.S. Treasury Bills		$ 1,999,905