Organization (Detail) (USD $)	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Aug. 03, 2006 PowerShares DB Agriculture Fund [Member]
Organization [Line Items]
Number of series of trusts			7
Partners' capital contribution	$ 1,000	$ 1,000	$ 1,000
General shares, shares issued	40	40	40
Number of shares issued per Basket	200,000