Document and Entity Information	6 Months Ended
	Jun. 30, 2017 shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Trading Symbol	UDN
Entity Registrant Name	POWERSHARES DB US DOLLAR INDEX BEARISH FUND
Entity Central Index Key	0001383149
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding	2,000,000