Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2012
Accounting Policies [Abstract]
Corporate Structure	Corporate Structure The Company was originally incorporated in Delaware in 1989. At the annual meeting of stockholders of the Delaware company on May 22, 2012, the stockholders, upon the recommendation of the Delaware company’s board of directors, approved a proposal to merge the Delaware company with and into its wholly-owned subsidiary, LJPC Merger Sub, Inc., for the purpose of changing the domicile of the Company from Delaware to California (the “Merger”). Following stockholder approval, the Merger was effected on June 7, 2012. As a result, the Company is now a California corporation and LJPC Merger Sub, Inc. changed its name to La Jolla Pharmaceutical Company. The authorized capital stock of the Company increased from 6,008,000,000 to 12,008,000,000 shares. All common and preferred shares of the Delaware company were exchanged for common and preferred shares of the Company.
Use of Estimates	Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited condensed financial statements and disclosures made in the accompanying notes to the unaudited condensed financial statements. These include the assumptions discussed below relating to the calculation of our derivative liabilities. Actual results could differ materially from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Effective January 1, 2012, the Company adopted the guidance issued by the FASB in May 2011, regarding common fair value measurements and disclosure requirements in U.S. GAAP and IFRS. This accounting standard clarifies the application of certain existing fair value measurement guidance and expands the disclosures for fair value measurements that are estimated using significant unobservable inputs. The adoption of this standard did not have a material impact on the financial position or results of operations of the Company. Effective January 1, 2012, the Company adopted the guidance issued by the FASB in June 2011 and amended in December 2011, regarding comprehensive income. This accounting standard (1) eliminates the option to present the components of other comprehensive income as part of the statement of changes in stockholders’ equity; and (2) requires the consecutive presentation of the statement of net income and other comprehensive income. The amendments do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income nor do the amendments affect how earnings per share is calculated or presented. As this accounting standard only requires enhanced disclosure, the adoption of this standard did not impact the Company’s financial position or results of operations.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets If indicators of impairment exist, the Company assesses the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through the undiscounted future operating cash flows. As a result of the negative results in the confirmatory preclinical study of LJP1485 in May 2011, the Company discontinued the development of LJP1485 in May 2011 and in June 2011 the Company sold the Compounds back to GliaMed for the same nominal amount that it had paid for them. Based on these events, the future cash flows from the patents related to the Compounds were no longer expected to exceed their carrying values and the assets became impaired as of May 31, 2011. Accordingly, during the quarter ended June 30, 2011, the Company recorded a non-cash charge of $243,000 to general and administrative expense for the impairment of long-lived assets to write down the value of the Company’s patents to their estimated fair values.
Reverse Stock Split	Reverse Stock Split The Board of Directors approved the reverse stock split (the “2012 Reverse Stock Split”) of the Company’s common stock, which became effective on February 17, 2012, with an exchange ratio of 1-for-100. As a result of the 2012 Reverse Stock Split, each 100 shares of the Company’s issued and outstanding common stock were automatically reclassified as and changed into one share of the Company’s common stock. No fractional shares were issued in connection with the 2012 Reverse Stock Split. Stockholders who were entitled to fractional shares instead became entitled to receive a cash payment in lieu of receiving fractional shares (after taking into account and aggregating all shares of the Company’s common stock then held by such stockholder) equal to the fractional share interest. The 2012 Reverse Stock Split affected all of the holders of the Company’s common stock uniformly. Effective on March 3, 2012, each share of 2012 New Preferred Stock was convertible into approximately 213,083 shares of common stock. The Board of Directors approved the reverse stock split (the “2011 Reverse Stock Split”) of the Company’s common stock, which became effective on April 14, 2011, with an exchange ratio of 1-for-100. As a result of the 2011 Reverse Stock Split, each 100 shares of the Company’s issued and outstanding common stock were automatically reclassified as and changed into one share of the Company’s common stock. No fractional shares were issued in connection with the 2011 Reverse Stock Split. Stockholders who were entitled to fractional shares instead became entitled to receive a cash payment in lieu of receiving fractional shares (after taking into account and aggregating all shares of the Company’s common stock then held by such stockholder) equal to the fractional share interest. The 2011 Reverse Stock Split affected all of the holders of the Company’s common stock uniformly. Effective on May 7, 2011, each share of New Preferred Stock was convertible into approximately 166,667 shares of common stock. All common stock share and per share information in the accompanying unaudited condensed financial statements have been restated to reflect retrospective application of the 2012 and 2011 Reverse Stock Split for all periods presented, except for par value per share and the number of authorized shares, which were not affected. Shares of the Company’s common stock underlying outstanding options and warrants were proportionately reduced and the exercise prices of outstanding options and warrants were proportionately increased in accordance with the terms of the agreements governing such securities. Shares of the Company’s common stock underlying outstanding convertible preferred stock and warrants were proportionately reduced and the conversion rates were proportionately decreased in accordance with the terms of the agreements governing such securities.
Net Income (Loss) Per Share	Net Income (Loss) Per Share Basic and diluted net income (loss) per share is computed using the weighted-average number of common shares outstanding during the periods. Basic earnings per share (“EPS”) is calculated by dividing the net income or loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted EPS is computed by dividing the net income or loss by the weighted-average number of common shares and common stock equivalents outstanding for the period issuable upon the conversion of preferred stock and exercise of stock options and warrants. These common stock equivalents are included in the calculation of diluted EPS only if their effect is dilutive (see Note 11). There is no difference between basic and diluted net loss per share for the six months ended June 30, 2012 and 2011 and the three months ended June 30, 2012 as potentially dilutive securities have been excluded from the calculation of diluted net loss per common share because the inclusion of such securities would be antidilutive.
Derivative Liabilities	Derivative Liabilities In May 2010, the Company entered into definitive agreements with institutional investors and affiliates for a private placement of common stock, redeemable convertible preferred stock and warrants to purchase convertible preferred stock for initial proceeds of $6,003,000 (the “May 2010 Financing”). In conjunction with the May 2010 Financing, the Company issued redeemable convertible preferred stock that contained certain embedded derivative features, as well as warrants that are accounted for as derivative liabilities (see Note 6). These derivative liabilities were determined to be ineligible for equity classification due to certain provisions of the underlying preferred stock, which is also ineligible for equity classification, whereby redemption is outside the sole control of the Company due to provisions that may result in an adjustment to their exercise or conversion price. The Company’s derivative liabilities were initially recorded at their estimated fair value on the date of issuance and are subsequently adjusted to reflect the estimated fair value at each period end, with any decrease or increase in the estimated fair value being recorded as other income or expense, accordingly. The fair value of these liabilities is estimated using option pricing models that are based on the individual characteristics of the common stock and preferred stock, the derivative liability on the valuation date, probabilities related to the Company’s operations and clinical development (based on industry data), as well as assumptions for volatility, remaining expected life, risk-free interest rate and, in some cases, credit spread. The option pricing models are particularly sensitive to changes in the aforementioned probabilities and the closing price per share of the Company’s common stock.

Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2012

Corporate Structure

The Company was originally incorporated in Delaware in 1989. At the annual meeting of stockholders of the Delaware company on May 22, 2012, the stockholders, upon the recommendation of the Delaware company’s board of directors, approved a proposal to merge the Delaware company with and into its wholly-owned subsidiary, LJPC Merger Sub, Inc., for the purpose of changing the domicile of the Company from Delaware to California (the “Merger”). Following stockholder approval, the Merger was effected on June 7, 2012. As a result, the Company is now a California corporation and LJPC Merger Sub, Inc. changed its name to La Jolla Pharmaceutical Company. The authorized capital stock of the Company increased from 6,008,000,000 to 12,008,000,000 shares. All common and preferred shares of the Delaware company were exchanged for common and preferred shares of the Company.

Use of Estimates

Use of Estimates

The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited condensed financial statements and disclosures made in the accompanying notes to the unaudited condensed financial statements. These include the assumptions discussed below relating to the calculation of our derivative liabilities. Actual results could differ materially from those estimates.

Recent Accounting Pronouncements

Recent Accounting Pronouncements

Effective January 1, 2012, the Company adopted the guidance issued by the FASB in May 2011, regarding common fair value measurements and disclosure requirements in U.S. GAAP and IFRS. This accounting standard clarifies the application of certain existing fair value measurement guidance and expands the disclosures for fair value measurements that are estimated using significant unobservable inputs. The adoption of this standard did not have a material impact on the financial position or results of operations of the Company.

Effective January 1, 2012, the Company adopted the guidance issued by the FASB in June 2011 and amended in December 2011, regarding comprehensive income. This accounting standard (1) eliminates the option to present the components of other comprehensive income as part of the statement of changes in stockholders’ equity; and (2) requires the consecutive presentation of the statement of net income and other comprehensive income. The amendments do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income nor do the amendments affect how earnings per share is calculated or presented. As this accounting standard only requires enhanced disclosure, the adoption of this standard did not impact the Company’s financial position or results of operations.

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets

If indicators of impairment exist, the Company assesses the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through the undiscounted future operating cash flows.

As a result of the negative results in the confirmatory preclinical study of LJP1485 in May 2011, the Company discontinued the development of LJP1485 in May 2011 and in June 2011 the Company sold the Compounds back to GliaMed for the same nominal amount that it had paid for them. Based on these events, the future cash flows from the patents related to the Compounds were no longer expected to exceed their carrying values and the assets became impaired as of May 31, 2011. Accordingly, during the quarter ended June 30, 2011, the Company recorded a non-cash charge of $243,000 to general and administrative expense for the impairment of long-lived assets to write down the value of the Company’s patents to their estimated fair values.

Reverse Stock Split

Reverse Stock Split

The Board of Directors approved the reverse stock split (the “2012 Reverse Stock Split”) of the Company’s common stock, which became effective on February 17, 2012, with an exchange ratio of 1-for-100. As a result of the 2012 Reverse Stock Split, each 100 shares of the Company’s issued and outstanding common stock were automatically reclassified as and changed into one share of the Company’s common stock. No fractional shares were issued in connection with the 2012 Reverse Stock Split. Stockholders who were entitled to fractional shares instead became entitled to receive a cash payment in lieu of receiving fractional shares (after taking into account and aggregating all shares of the Company’s common stock then held by such stockholder) equal to the fractional share interest. The 2012 Reverse Stock Split affected all of the holders of the Company’s common stock uniformly. Effective on March 3, 2012, each share of 2012 New Preferred Stock was convertible into approximately 213,083 shares of common stock.

The Board of Directors approved the reverse stock split (the “2011 Reverse Stock Split”) of the Company’s common stock, which became effective on April 14, 2011, with an exchange ratio of 1-for-100. As a result of the 2011 Reverse Stock Split, each 100 shares of the Company’s issued and outstanding common stock were automatically reclassified as and changed into one share of the Company’s common stock. No fractional shares were issued in connection with the 2011 Reverse Stock Split. Stockholders who were entitled to fractional shares instead became entitled to receive a cash payment in lieu of receiving fractional shares (after taking into account and aggregating all shares of the Company’s common stock then held by such stockholder) equal to the fractional share interest. The 2011 Reverse Stock Split affected all of the holders of the Company’s common stock uniformly. Effective on May 7, 2011, each share of New Preferred Stock was convertible into approximately 166,667 shares of common stock.

All common stock share and per share information in the accompanying unaudited condensed financial statements have been restated to reflect retrospective application of the 2012 and 2011 Reverse Stock Split for all periods presented, except for par value per share and the number of authorized shares, which were not affected. Shares of the Company’s common stock underlying outstanding options and warrants were proportionately reduced and the exercise prices of outstanding options and warrants were proportionately increased in accordance with the terms of the agreements governing such securities. Shares of the Company’s common stock underlying outstanding convertible preferred stock and warrants were proportionately reduced and the conversion rates were proportionately decreased in accordance with the terms of the agreements governing such securities.

Net Income (Loss) Per Share

Net Income (Loss) Per Share

Basic and diluted net income (loss) per share is computed using the weighted-average number of common shares outstanding during the periods. Basic earnings per share (“EPS”) is calculated by dividing the net income or loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted EPS is computed by dividing the net income or loss by the weighted-average number of common shares and common stock equivalents outstanding for the period issuable upon the conversion of preferred stock and exercise of stock options and warrants. These common stock equivalents are included in the calculation of diluted EPS only if their effect is dilutive (see Note 11). There is no difference between basic and diluted net loss per share for the six months ended June 30, 2012 and 2011 and the three months ended June 30, 2012 as potentially dilutive securities have been excluded from the calculation of diluted net loss per common share because the inclusion of such securities would be antidilutive.

Derivative Liabilities

Derivative Liabilities

In May 2010, the Company entered into definitive agreements with institutional investors and affiliates for a private placement of common stock, redeemable convertible preferred stock and warrants to purchase convertible preferred stock for initial proceeds of $6,003,000 (the “May 2010 Financing”). In conjunction with the May 2010 Financing, the Company issued redeemable convertible preferred stock that contained certain embedded derivative features, as well as warrants that are accounted for as derivative liabilities (see Note 6). These derivative liabilities were determined to be ineligible for equity classification due to certain provisions of the underlying preferred stock, which is also ineligible for equity classification, whereby redemption is outside the sole control of the Company due to provisions that may result in an adjustment to their exercise or conversion price.

The Company’s derivative liabilities were initially recorded at their estimated fair value on the date of issuance and are subsequently adjusted to reflect the estimated fair value at each period end, with any decrease or increase in the estimated fair value being recorded as other income or expense, accordingly. The fair value of these liabilities is estimated using option pricing models that are based on the individual characteristics of the common stock and preferred stock, the derivative liability on the valuation date, probabilities related to the Company’s operations and clinical development (based on industry data), as well as assumptions for volatility, remaining expected life, risk-free interest rate and, in some cases, credit spread. The option pricing models are particularly sensitive to changes in the aforementioned probabilities and the closing price per share of the Company’s common stock.

- Definition

Disclosure of accounting policy for its derivative instruments and hedging activities.

+ References

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+ Details

- Definition

Disclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.

+ References+ Details

- Definition

Disclosure of accounting policy for recognizing and measuring the impairment of long-lived assets. An entity also may disclose its accounting policy for long-lived assets to be sold. This policy excludes goodwill and intangible assets.

+ References+ Details

- Definition

Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.

+ References+ Details