Related Party Transactions	12 Months Ended
Dec. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions In March 2012, the Company acquired all of the membership interests of Éclat from Breaking Stick Holdings, L.L.C. (“Breaking Stick”, formerly Éclat Holdings), an affiliate of Deerfield Capital L.P (“Deerfield”), a significant shareholder of the Company. During the three months ended December 31, 2019, Deerfield sold all of their shares. At December 31, 2019, the remaining consideration obligation for this transaction consisted of commitments to make earnout payments to Breaking Stick of 20% of any gross profit generated by certain Éclat products (the “Products”). Breaking Stick is majority owned by Deerfield, with a minority interest owned by certain current and former employees. The Company entered into a Security Agreement dated March 13, 2012 with Breaking Stick, whereby Breaking Stick was granted a security interest in various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Breaking Stick under the Royalty Agreement. As part of a February 2013 debt financing transaction conducted with Deerfield Management, Éclat entered into a Royalty Agreement with Horizon Santé FLML, Sarl and Deerfield Private Design Fund II, L.P., both affiliates of the Deerfield Entities (together, “Deerfield PDF/Horizon”). The Royalty Agreement provides for the Company to pay Deerfield PDF/Horizon 1.75% of the net sales of the Products sold by the Company and any of our affiliates until December 31, 2024, with royalty payments paid in arrears for each calendar quarter during the term of the Royalty Agreement. The Company has also entered into a Security Agreement dated February 4, 2013 with Deerfield PDF/Horizon, whereby Deerfield PDF/Horizon was granted a security interest in the various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Deerfield PDF/Horizon under the Royalty Agreement. As part of a December 2013 debt financing transaction conducted with Broadfin Healthcare Master Fund (“Broadfin”), the Company also entered into a Royalty Agreement with Broadfin, a significant shareholder of the Company, dated as of December 3, 2013 (the “Broadfin Royalty Agreement”). During the three months ended December 31, 2019, Broadfin sold a majority of their shares and was not a significant shareholder at December 31, 2019. Pursuant to the Broadfin Royalty Agreement, the Company is required to pay a royalty of 0.834% on the net sales of certain products sold by the Company and any of our affiliates until December 31, 2024 with royalty payments paid in arrears for each calendar quarter during the term of the Royalty Agreement. We also entered into a Security Agreement dated December 3, 2013 with Broadfin, whereby Broadfin was granted a security interest in the various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Broadfin under the Royalty Agreement. The Company entered into an agreement dated February 5, 2016 to acquire FSC Holdings, LLC (“FSC”), a specialty pharmaceutical company dedicated to providing innovative solutions to unmet medical needs for pediatric patients, from Deerfield CSF, LLC, a Deerfield Management company (“Deerfield”), a related party. Under the terms of the acquisition, which was completed on February 8, 2016, the Company was to pay $1,050 annually for five years with a final payment in January 2021 of $15,000 for a total of $20,250 to Deerfield for all of the equity interests in FSC. The Company will also pay Deerfield a 15% royalty per annum on net sales of the current FSC products, up to $12,500 for a period not exceeding ten years. These obligations were assumed by Cerecor in connection with the divestiture of the Company’s pediatric products on February 16, 2018. In connection with the divestiture, the Company provided its guarantee in favor of Deerfield and in return, Armistice Capital Master Fund, Inc., the majority shareholder of Cerecor, guaranteed to the Company the payment by Cerecor of the Assumed Obligations mentioned in Note 17: Divestiture of the Pediatric Assets. On October 10, 2019, Cerecor entered into a purchase and sale agreement with Aytu BioScience, Inc (“Buyer”) pursuant to which the Buyer will purchase certain assets from Cerecor and assume certain of Cerecor’s liabilities, including all of Cerecor’s liabilities assumed as part of the Purchase Agreement discussed in Note 17. As part of this transaction, on November 1, 2019, Armistice has agreed to deposit $15,000 in an escrow account governed by an escrow agreement between Armistice and Deerfield having the purpose of securing the $15,000 balloon payment due January 2021 as part of the Membership Interest Purchase Agreement. As part of the Cerecor transaction with the buyer, Deerfield contractually acknowledges and agrees that it will seek payment from the escrow funds before requesting payment from the Company pursuant to the Deerfield Guarantee discussed above. Due to the change in circumstances, another valuation was performed based on an analysis of the possible timing of the updated possible cash flow which excludes the $15,000 that Armistice has deposited in an escrow account. See Note 17 for further discussion around the divestiture.

Related Party Transactions

In March 2012, the Company acquired all of the membership interests of Éclat from Breaking Stick Holdings, L.L.C. (“Breaking Stick”, formerly Éclat Holdings), an affiliate of Deerfield Capital L.P (“Deerfield”), a significant shareholder of the Company. During the three months ended December 31, 2019, Deerfield sold all of their shares. At December 31, 2019, the remaining consideration obligation for this transaction consisted of commitments to make earnout payments to Breaking Stick of 20% of any gross profit generated by certain Éclat products (the “Products”). Breaking Stick is majority owned by Deerfield, with a minority interest owned by certain current and former employees. The Company entered into a Security Agreement dated March 13, 2012 with Breaking Stick, whereby Breaking Stick was granted a security interest in various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Breaking Stick under the Royalty Agreement.

As part of a February 2013 debt financing transaction conducted with Deerfield Management, Éclat entered into a Royalty Agreement with Horizon Santé FLML, Sarl and Deerfield Private Design Fund II, L.P., both affiliates of the Deerfield Entities (together, “Deerfield PDF/Horizon”). The Royalty Agreement provides for the Company to pay Deerfield PDF/Horizon 1.75% of the net sales of the Products sold by the Company and any of our affiliates until December 31, 2024, with royalty payments paid in arrears for each calendar quarter during the term of the Royalty Agreement. The Company has also entered into a Security Agreement dated February 4, 2013 with Deerfield PDF/Horizon, whereby Deerfield PDF/Horizon was granted a security interest in the various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Deerfield PDF/Horizon under the Royalty Agreement.

As part of a December 2013 debt financing transaction conducted with Broadfin Healthcare Master Fund (“Broadfin”), the Company also entered into a Royalty Agreement with Broadfin, a significant shareholder of the Company, dated as of December 3, 2013 (the “Broadfin Royalty Agreement”). During the three months ended December 31, 2019, Broadfin sold a majority of their shares and was not a significant shareholder at December 31, 2019. Pursuant to the Broadfin Royalty Agreement, the Company is required to pay a royalty of 0.834% on the net sales of certain products sold by the Company and any of our affiliates until December 31, 2024 with royalty payments paid in arrears for each calendar quarter during the term of the Royalty Agreement. We also entered into a Security Agreement dated December 3, 2013 with Broadfin, whereby Broadfin was granted a security interest in the various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Broadfin under the Royalty Agreement.

The Company entered into an agreement dated February 5, 2016 to acquire FSC Holdings, LLC (“FSC”), a specialty pharmaceutical company dedicated to providing innovative solutions to unmet medical needs for pediatric patients, from Deerfield CSF, LLC, a Deerfield Management company (“Deerfield”), a related party. Under the terms of the acquisition, which was completed on February 8, 2016, the Company was to pay $1,050 annually for five years with a final payment in January 2021 of $15,000 for a total of $20,250 to Deerfield for all of the equity interests in FSC. The Company will also pay Deerfield a 15% royalty per annum on net sales of the current FSC products, up to $12,500 for a period not exceeding ten years. These obligations were assumed by Cerecor in connection with the divestiture of the Company’s pediatric products on February 16, 2018. In connection with the divestiture, the Company provided its guarantee in favor of Deerfield and in return, Armistice Capital Master Fund, Inc., the majority shareholder of Cerecor, guaranteed to the Company the payment by Cerecor of the Assumed Obligations mentioned in Note 17: Divestiture of the Pediatric Assets. On October 10, 2019, Cerecor entered into a purchase and sale agreement with Aytu BioScience, Inc (“Buyer”) pursuant to which the Buyer will purchase certain assets from Cerecor and assume certain of Cerecor’s liabilities, including all of Cerecor’s liabilities assumed as part of the Purchase Agreement discussed in Note 17. As part of this transaction, on November 1, 2019, Armistice has agreed to deposit $15,000 in an escrow account governed by an escrow agreement between Armistice and Deerfield having the purpose of securing the $15,000 balloon payment due January 2021 as part of the Membership Interest Purchase Agreement. As part of the Cerecor transaction with the buyer, Deerfield contractually acknowledges and agrees that it will seek payment from the escrow funds before requesting payment from the Company pursuant to the Deerfield Guarantee discussed above. Due to the change in circumstances, another valuation was performed based on an analysis of the possible timing of the updated possible cash flow which excludes the $15,000 that Armistice has deposited in an escrow account. See Note 17 for further discussion around the divestiture.