Convertible Preferred Stock And Stockholders' Equity (Summary Of Reserved Shares Of Common Stock) (Details) - shares	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved shares of common stock	88,525,291	3,083,105
Series A Convertible Preferred Stock Series [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved shares of common stock	47,844,562
Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved shares of common stock	38,963,443	2,120,365
Stock Award Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved shares of common stock	1,524,996	731,442
2009 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved shares of common stock	192,290	231,298