Stockholders' Equity (Summary Of Warrants Outstanding) (Details) (Warrant [Member], USD $)	Jul. 31, 2012
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Outstanding	427,312
10/19/12 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	57.36
Class of Warrant or Right, Outstanding	52,411
10/19/2012 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	68.80
Class of Warrant or Right, Outstanding	20,967
05/07/14 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	16.50
Class of Warrant or Right, Outstanding	11,363
05/27/14 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	18.96
Class of Warrant or Right, Outstanding	45,503
05/27/2014 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	21.12
Class of Warrant or Right, Outstanding	5,532
03/03/15 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	16.80
Class of Warrant or Right, Outstanding	52,836
01/13/16 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	3.52
Class of Warrant or Right, Outstanding	81,280
12/14/16 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	3.61
Class of Warrant or Right, Outstanding	25,000
12/24/16 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	3.28
Class of Warrant or Right, Outstanding	132,420