Licensed Technology	12 Months Ended
Dec. 31, 2018
Research and Development [Abstract]
Licensed Technology	Licensed Technology The George Washington University In December 2014, the Company entered into a patent license agreement with the George Washington University (GW), which the parties amended and restated on March 1, 2016. Pursuant to this license agreement, GW exclusively licensed to the Company certain intellectual property rights relating to GIAPREZA, including the exclusive rights to certain issued patents and patent applications covering GIAPREZA. Under this license agreement, the Company is obligated to use commercially reasonable efforts to develop, commercialize, market and sell GIAPREZA. The Company has paid a one-time license initiation fee, annual maintenance fees, an amendment fee and additional payments following the achievement of certain development and regulatory milestones including FDA approval. The Company may be obligated to make additional milestone payments of up to $0.5 million in the aggregate. Following the commencement of commercial sales of GIAPREZA, the Company is obligated to pay tiered royalties in the low- to mid- single digits on products covered by the licensed rights. The patents and patent applications covered by the GW license agreement expire between 2029 and 2038, and the obligation to pay royalties under this agreement extend through the last-to-expire patent covering GIAPREZA. Inserm Transfert SA In February 2014, the Company entered into a license agreement with Inserm Transfert SA (Inserm). Pursuant to this license agreement, Inserm exclusively licensed to the Company certain intellectual property rights relating to LJPC-401. Under this license agreement, the Company has paid a one-time license initiation fee, annual maintenance fees and additional payments following the achievement of certain development milestones. The Company may be obligated to make additional payments of up to $3.7 million upon the achievement of certain development milestones and regulatory approval on products covered by the licensed patent rights. Following the commencement of commercial sales of a product covered by the licensed intellectual property, the Company will be obligated to pay tiered royalties in the low- to mid- single digits on products covered by the licensed rights. The patents and patent applications covered by the Inserm license agreement expire between 2022 and 2038, and the obligation to pay royalties under this agreement extend through the last-to-expire patent covering a licensed product. Other In-Licensed Technology The Company continues to seek additional technology for potential new development programs and, as a result, has entered into various licensing agreements for intellectual property rights. The Company has incurred licensing and milestone fees of $0.7 million, $1.6 million and $0.5 million recorded in research and development expense in connection with its licensing agreements for the years ended December 31, 2018, 2017 and 2016, respectively. See Note 11 for future minimum licensing payment commitments.

Licensed Technology

The George Washington University

In December 2014, the Company entered into a patent license agreement with the George Washington University (GW), which the parties amended and restated on March 1, 2016. Pursuant to this license agreement, GW exclusively licensed to the Company certain intellectual property rights relating to GIAPREZA, including the exclusive rights to certain issued patents and patent applications covering GIAPREZA. Under this license agreement, the Company is obligated to use commercially reasonable efforts to develop, commercialize, market and sell GIAPREZA. The Company has paid a one-time license initiation fee, annual maintenance fees, an amendment fee and additional payments following the achievement of certain development and regulatory milestones including FDA approval. The Company may be obligated to make additional milestone payments of up to $0.5 million in the aggregate. Following the commencement of commercial sales of GIAPREZA, the Company is obligated to pay tiered royalties in the low- to mid- single digits on products covered by the licensed rights. The patents and patent applications covered by the GW license agreement expire between 2029 and 2038, and the obligation to pay royalties under this agreement extend through the last-to-expire patent covering GIAPREZA.

Inserm Transfert SA

In February 2014, the Company entered into a license agreement with Inserm Transfert SA (Inserm). Pursuant to this license agreement, Inserm exclusively licensed to the Company certain intellectual property rights relating to LJPC-401. Under this license agreement, the Company has paid a one-time license initiation fee, annual maintenance fees and additional payments following the achievement of certain development milestones. The Company may be obligated to make additional payments of up to $3.7 million upon the achievement of certain development milestones and regulatory approval on products covered by the licensed patent rights. Following the commencement of commercial sales of a product covered by the licensed intellectual property, the Company will be obligated to pay tiered royalties in the low- to mid- single digits on products covered by the licensed rights. The patents and patent applications covered by the Inserm license agreement expire between 2022 and 2038, and the obligation to pay royalties under this agreement extend through the last-to-expire patent covering a licensed product.

Other In-Licensed Technology

The Company continues to seek additional technology for potential new development programs and, as a result, has entered into various licensing agreements for intellectual property rights. The Company has incurred licensing and milestone fees of $0.7 million, $1.6 million and $0.5 million recorded in research and development expense in connection with its licensing agreements for the years ended December 31, 2018, 2017 and 2016, respectively. See Note 11 for future minimum licensing payment commitments.