Condensed Consolidated Statements of Stockholders' Equity (Deficit) (USD $) | Total | Series B-1 convertible preferred stock [Member] | Series C-3 convertible preferred stock [Member] | Series E-1 convertible preferred stock [Member] | Series E- 2 convertible preferred stock [Member] | Series E-3 convertible preferred stock [Member] | Series E-4 convertible preferred stock [Member] | Series E-5 convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Convertible preferred stock [Member] | Notes Receivable from Stockholders [Member] | Notes Receivable from Stockholders [Member] | Notes Receivable from Stockholders [Member] | Notes Receivable from Stockholders [Member] | Common Stock [Member] | Additional paid-in capital [Member] | Additional paid-in capital [Member] | Additional paid-in capital [Member] | Additional paid-in capital [Member] | Additional paid-in capital [Member] | Additional paid-in capital [Member] | Other Comprehensive Income (Loss) [Member] | Deficit Accumulated During the Development Stage [Member] | Deficit Accumulated During the Development Stage [Member] | Deficit Accumulated During the Development Stage [Member] | Deficit Accumulated During the Development Stage [Member] |
In Thousands, except Share data | Series A convertible preferred stock [Member] | Series B-1 convertible preferred stock [Member] | Series B-2 convertible preferred stock [Member] | Series C- 1 convertible preferred stock [Member] | Series C-2 convertible preferred stock [Member] | Series C-3 convertible preferred stock [Member] | Series D convertible preferred stock [Member] | Series E-1 convertible preferred stock [Member] | Series E- 2 convertible preferred stock [Member] | Series E-3 convertible preferred stock [Member] | Series E-4 convertible preferred stock [Member] | Series E-5 convertible preferred stock [Member] | Series A convertible preferred stock [Member] | Series C- 1 convertible preferred stock [Member] | Series D convertible preferred stock [Member] | Series B-1 convertible preferred stock [Member] | Series C-3 convertible preferred stock [Member] | Series E-1 convertible preferred stock [Member] | Series E-4 convertible preferred stock [Member] | Series E-5 convertible preferred stock [Member] | Series E-1 convertible preferred stock [Member] | Series E- 2 convertible preferred stock [Member] | Series E-3 convertible preferred stock [Member] |
Beginning Balance at Dec. 31, 2001 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | 42,876 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 179,800 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | $483 | ' | ' | ' | ' | ' | ' | ' | ' | $1,415 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ($25) | ' | ' | ' | $483 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -1,884 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -1,884 | ' | ' | ' |
Ending Balance at Dec. 31, 2002 | -1,401 | ' | ' | ' | ' | ' | ' | ' | 1,415 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -25 | ' | ' | ' | ' | 483 | ' | ' | ' | ' | ' | ' | -1,884 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2002 | ' | ' | ' | ' | ' | ' | ' | ' | 42,876 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 179,800 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 9 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 9 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | 11,851 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2,400 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | 6 | ' | ' | ' | ' | ' | ' | ' | ' | 391 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Repayment of notes receivable from stockholders | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 25 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -1,180 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -1,180 | ' | ' | ' |
Ending Balance at Dec. 31, 2003 | -2,566 | ' | ' | ' | ' | ' | ' | ' | 1,806 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 498 | ' | ' | ' | ' | ' | ' | -3,064 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2003 | ' | ' | ' | ' | ' | ' | ' | ' | 54,727 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 182,200 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 8 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 8 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 199,224 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6,837 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Issuance of Series B-1 convertible preferred stock warrants in connection with conversion of convertible note | ' | 15 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 15 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Common stock warrants issued in connection with convertible notes (January through June and September through December) | ' | 11 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 11 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -2,534 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -2,534 | ' | ' | ' |
Ending Balance at Dec. 31, 2004 | -5,066 | ' | ' | ' | ' | ' | ' | ' | 8,643 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 532 | ' | ' | ' | ' | ' | ' | -5,598 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2004 | ' | ' | ' | ' | ' | ' | ' | ' | 253,951 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 182,200 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Unrealized loss on marketable securities | -3 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -3 | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 134,843 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6,230 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -5,004 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -5,004 | ' | ' | ' |
Ending Balance at Dec. 31, 2005 | -10,073 | ' | ' | ' | ' | ' | ' | ' | 14,873 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 532 | ' | ' | ' | ' | ' | -3 | -10,602 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2005 | ' | ' | ' | ' | ' | ' | ' | ' | 388,794 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 182,200 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 75 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 75 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Reclassification of convertible preferred stock warrants to liabilities | -26 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -26 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Realized loss on marketable securities | 3 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 3 | ' | ' | ' | ' |
Net loss | -9,378 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -9,378 | ' | ' | ' |
Ending Balance at Dec. 31, 2006 | -19,399 | ' | ' | ' | ' | ' | ' | ' | 14,873 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 581 | ' | ' | ' | ' | ' | ' | -19,980 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2006 | ' | ' | ' | ' | ' | ' | ' | ' | 388,794 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 182,200 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 198 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 198 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares, value | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 16,710 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -15 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 279,425 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 64,242 | 144,927 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | ' | ' | 1,708 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 4,972 | 15,452 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,708 | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 228 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, value | 2 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -19,965 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -19,965 | ' | ' | ' |
Ending Balance at Dec. 31, 2007 | -37,456 | ' | ' | ' | ' | ' | ' | ' | 52,007 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -15 | ' | ' | ' | ' | 2,489 | ' | ' | ' | ' | ' | ' | -39,945 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2007 | ' | ' | ' | ' | ' | ' | ' | ' | 877,388 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 182,428 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 404 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 404 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 96,969 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 7,400 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 638 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, value | 4 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 4 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -21,966 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -21,966 | ' | ' | ' |
Ending Balance at Dec. 31, 2008 | -59,014 | ' | ' | ' | ' | ' | ' | ' | 59,407 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -15 | ' | ' | ' | ' | 2,897 | ' | ' | ' | ' | ' | ' | -61,911 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2008 | ' | ' | ' | ' | ' | ' | ' | ' | 974,357 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 183,066 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 391 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 391 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 383,851 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 25,450 | ' | ' | ' | ' | ' | ' | ' | ' | -6 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 8,634 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, value | 96 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 96 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Repayment of notes receivable from stockholders | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 15 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -24,064 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -24,064 | ' | ' | ' |
Ending Balance at Dec. 31, 2009 | -82,591 | ' | ' | ' | ' | ' | ' | ' | 84,857 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -6 | ' | ' | ' | ' | 3,384 | ' | ' | ' | ' | ' | ' | -85,975 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2009 | ' | ' | ' | ' | ' | ' | ' | ' | 1,358,208 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 191,700 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 455 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 455 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 159,023 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 10,576 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 3,466 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, value | 10 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 10 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Repayment of notes receivable from stockholders | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -29,229 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -29,229 | ' | ' | ' |
Ending Balance at Dec. 31, 2010 | -111,355 | ' | ' | ' | ' | ' | ' | ' | 95,433 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 3,849 | ' | ' | ' | ' | ' | ' | -115,204 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2010 | ' | ' | ' | ' | ' | ' | ' | ' | 1,517,231 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 195,166 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 273 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 273 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Issuance of common stock subject to repurchase | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 3,333 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 150 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Common stock warrants issued in connection with convertible notes (January through June and September through December) | 463 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 463 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -44,863 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -44,863 | ' | ' | ' |
Ending Balance at Dec. 31, 2011 | -155,482 | ' | ' | ' | ' | ' | ' | ' | 95,433 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 4,585 | ' | ' | ' | ' | ' | ' | -160,067 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2011 | ' | ' | ' | ' | ' | ' | ' | ' | 1,517,381 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 198,499 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 79 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 79 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Common stock warrants issued in connection with convertible notes (January through June and September through December) | 153 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 153 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2,530 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, value | 6 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of common stock warrants, value | 1 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of common stock warrants, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2,995 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Preferred stock modification | ' | ' | -3,225 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -3,225 | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -58,259 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -58,259 | ' | ' | ' |
Ending Balance at Dec. 31, 2012 | -216,727 | ' | ' | ' | ' | ' | ' | ' | 95,433 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,599 | ' | ' | ' | ' | ' | ' | -218,326 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2012 | ' | ' | ' | ' | ' | ' | ' | ' | 1,517,381 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 204,024 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | 548 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 548 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares, value | ' | ' | ' | 63 | ' | ' | 32,008 | ' | ' | ' | ' | ' | ' | ' | ' | ' | -63 | ' | ' | 66,954 | ' | ' | ' | ' | ' | ' | ' | ' | ' | 63 | 32,008 | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -1,694 | ' | ' | 4,748,484 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares | ' | ' | ' | 11,256 | 39,000 | 24,638 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -11,256 | -39,000 | -24,638 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 11,256 | 39,000 | 24,638 |
Conversion of convertible debt into shares, shares | ' | ' | ' | ' | ' | ' | ' | ' | 607,476 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,810,441 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 36,375 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 4,284 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, value | 11 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 11 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Convertible preferred stock, deemed dividend | ' | ' | ' | ' | ' | ' | ' | -177 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 177 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -177 | ' | ' | ' | ' | ' |
Exercise of common stock warrants, value | 7 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 7 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of common stock warrants, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 52,481 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Convertible preferred stock, deemed dividend, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 7,911 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Issuance of common stock warrants in connection with Series E-5 convertible preferred stock financing | ' | ' | ' | ' | ' | ' | ' | 4,272 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 4,272 | ' | ' | ' | ' | ' |
Net loss | -52,448 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -52,448 | ' | ' | ' |
Ending Balance at Dec. 31, 2013 | -157,549 | ' | ' | ' | ' | ' | ' | ' | 123,982 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 38,331 | ' | ' | ' | ' | ' | ' | -195,880 | ' | ' | ' |
Ending Balance, Shares at Dec. 31, 2013 | ' | ' | ' | ' | ' | ' | ' | ' | 8,689,999 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 260,789 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Compensation expense relating to employee stock purchase plan | 209 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 209 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Stock-based compensation expense | -810 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Non-employee stock-based compensation expense related to stock options | 325 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 325 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Employee stock-based compensation expense related to stock options | 276 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 276 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of preferred stock to common stock in connection with initial public offering | 123,981 | ' | ' | ' | ' | ' | ' | ' | -123,982 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 9 | 123,972 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of preferred stock to common stock in connection with initial public offering, shares | ' | ' | ' | ' | ' | ' | ' | ' | -8,689,999 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 8,689,999 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of preferred stock warrants to common stock warrants in connection with initial public offering | 1,441 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,441 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Issuance of common stock in connection with initial public offering, net of underwriting discounts, commissions and issuance costs | 98,644 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 7 | 98,637 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Issuance of common stock in connection with initial public offering, net of underwriting discounts, commissions and issuance costs, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6,900,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares | 26,206 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2 | 26,204 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Conversion of convertible debt into shares, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,637,846 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Issuance of common stock upon net exercise of common stock warrants and related extinguishment of warrant liability in connection with initial public offering | 6,490 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1 | 6,489 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Issuance of common stock upon net exercise of common stock warrants and related extinguishment of warrant liability in connection with initial public offering, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,158,443 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,111 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Shares issued, value | 17 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 17 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, shares | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 5,113 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Exercise of stock options, value | 15 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 15 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Termination of repurchase rights related to vesting of common stock issued pursuant to early exercises | 58 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 58 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Net loss | -21,426 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -21,426 | ' | ' | ' |
Ending Balance at Mar. 31, 2014 | $78,687 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $19 | $295,974 | ' | ' | ' | ' | ' | ' | ($217,306) | ' | ' | ' |
Ending Balance, Shares at Mar. 31, 2014 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 18,653,301 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |