Deferred Royalty Obligation	6 Months Ended
Jun. 30, 2018
Debt Disclosure [Abstract]
Deferred Royalty Obligation	Deferred Royalty Obligation On May 10, 2018, the Company closed a $125.0 million royalty financing agreement (the Royalty Agreement) with HealthCare Royalty Partners (HCR). Under the terms of the Royalty Agreement, the Company received $125.0 million in exchange for tiered royalty payments on worldwide net product sales of GIAPREZA. HCR is entitled to receive royalties on worldwide net product sales of GIAPREZA beginning April 1, 2018. Payments to HCR under the Royalty Agreement start annually at a maximum royalty rate, with step-downs based on the achievement of annual net product sales thresholds. Through December 31, 2021, the royalty rate will be a maximum of 10%. Starting January 1, 2022, the maximum royalty rate may increase by 4% if an agreed-upon, cumulative sales threshold has not been met, and, starting January 1, 2024, the maximum royalty rate may increase by an additional 4% if a different agreed-upon, cumulative sales threshold has not been met. The Royalty Agreement is subject to maximum aggregate royalty payments to HCR of 180% of the $125.0 million to be received by the Company, at which time the payment obligations under the Royalty Agreement would expire. The Royalty Agreement was entered into by the Company’s wholly owned subsidiary, La Jolla Pharma, LLC, and HCR has no recourse under the Royalty Agreement against La Jolla Pharmaceutical Company or any assets other than GIAPREZA. On receipt of the $125.0 million payment from HCR, the Company recorded a deferred royalty obligation of $125.0 million, net of debt issuance costs of $0.7 million. For both the three and six months ended June 30, 2018, the Company recognized interest expense, including amortization of the debt discount, of $1.7 million. The carrying value of the deferred royalty obligation as of June 30, 2018 was $124.3 million, net of unamortized debt discount of $0.7 million, and was classified as non-current. Accrued interest expense of $1.6 million is included in accrued expenses in the condensed consolidated balance sheet as of June 30, 2018. In the event of certain material breaches of the Royalty Agreement, HCR would have the right to terminate the Royalty Agreement and demand payment of an amount equal to either $125.0 million, minus aggregate royalties paid to HCR, or $225.0 million, minus aggregate royalties paid to HCR. The Company concluded that certain of these material breaches are embedded derivatives that require bifurcation from the deferred royalty obligation and fair value recognition. The Company determined the fair value of each derivative by assessing the probability of each event occurring, as well as the potential repayment amounts and timing of such repayments that would result under various scenarios. As a result of this assessment, the Company determined that the fair value of the embedded derivatives is immaterial as of June 30, 2018. Each reporting period, the Company estimates the fair value of the embedded derivatives until the features lapse and/or the termination of the Royalty Agreement. Any change in the fair value of the embedded derivatives will be recorded as either a gain or loss on the consolidated statements of operations.

Deferred Royalty Obligation

On May 10, 2018, the Company closed a $125.0 million royalty financing agreement (the Royalty Agreement) with HealthCare Royalty Partners (HCR). Under the terms of the Royalty Agreement, the Company received $125.0 million in exchange for tiered royalty payments on worldwide net product sales of GIAPREZA. HCR is entitled to receive royalties on worldwide net product sales of GIAPREZA beginning April 1, 2018. Payments to HCR under the Royalty Agreement start annually at a maximum royalty rate, with step-downs based on the achievement of annual net product sales thresholds. Through December 31, 2021, the royalty rate will be a maximum of 10%. Starting January 1, 2022, the maximum royalty rate may increase by 4% if an agreed-upon, cumulative sales threshold has not been met, and, starting January 1, 2024, the maximum royalty rate may increase by an additional 4% if a different agreed-upon, cumulative sales threshold has not been met. The Royalty Agreement is subject to maximum aggregate royalty payments to HCR of 180% of the $125.0 million to be received by the Company, at which time the payment obligations under the Royalty Agreement would expire. The Royalty Agreement was entered into by the Company’s wholly owned subsidiary, La Jolla Pharma, LLC, and HCR has no recourse under the Royalty Agreement against La Jolla Pharmaceutical Company or any assets other than GIAPREZA.

On receipt of the $125.0 million payment from HCR, the Company recorded a deferred royalty obligation of $125.0 million, net of debt issuance costs of $0.7 million. For both the three and six months ended June 30, 2018, the Company recognized interest expense, including amortization of the debt discount, of $1.7 million. The carrying value of the deferred royalty obligation as of June 30, 2018 was $124.3 million, net of unamortized debt discount of $0.7 million, and was classified as non-current. Accrued interest expense of $1.6 million is included in accrued expenses in the condensed consolidated balance sheet as of June 30, 2018.

In the event of certain material breaches of the Royalty Agreement, HCR would have the right to terminate the Royalty Agreement and demand payment of an amount equal to either $125.0 million, minus aggregate royalties paid to HCR, or $225.0 million, minus aggregate royalties paid to HCR. The Company concluded that certain of these material breaches are embedded derivatives that require bifurcation from the deferred royalty obligation and fair value recognition. The Company determined the fair value of each derivative by assessing the probability of each event occurring, as well as the potential repayment amounts and timing of such repayments that would result under various scenarios. As a result of this assessment, the Company determined that the fair value of the embedded derivatives is immaterial as of June 30, 2018. Each reporting period, the Company estimates the fair value of the embedded derivatives until the features lapse and/or the termination of the Royalty Agreement. Any change in the fair value of the embedded derivatives will be recorded as either a gain or loss on the consolidated statements of operations.