v3.20.1

Share capital - Capital increase (Details) - EUR (€) | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure of classes of share capital [line items] |  |  |
Balance at beginning of period, shares | 54,465,421 | 50,936,778 | 46,256,078
Balance at beginning of period | € 1,214,249,000 | € 1,011,983,000 | € 758,701,000
Share capital | 287,282,000 | 236,540,000 | 233,414,000
Net issue of equity | 960,087,000 | 296,188,000 | 363,924,000
Share premium | 2,703,583,000 | 1,277,780,000 | 993,025,000
Exercise of warrants | € 17,167,000 | € 7,657,000 | € 5,288,000
Average exercise price warrants | € 22.8 | € 13.5 | € 14.4
Balance at end of period, shares | 64,666,802 | 54,465,421 | 50,936,778
Balance at end of period | € 2,875,658,000 | € 1,214,249,000 | € 1,011,983,000
Par value of shares | € 5.41 |  |
April 6, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  |  | 247,070
Average exercise price warrants |  |  | € 16.33
Closing share price on date of capital increase |  |  | € 84.60
June 20, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  |  | 52,030
Average exercise price warrants |  |  | € 12.14
Closing share price on date of capital increase |  |  | € 70.66
September 21, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  |  | 28,100
Average exercise price warrants |  |  | € 9.55
Closing share price on date of capital increase |  |  | € 84.62
November 23, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  |  | 41,000
Average exercise price warrants |  |  | € 8.63
Closing share price on date of capital increase |  |  | € 77.53
March 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  | 298,184 |
Average exercise price warrants |  | € 13.16 |
Closing share price on date of capital increase |  | € 83.72 |
June 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  | 102,801 |
Average exercise price warrants |  | € 13.01 |
Closing share price on date of capital increase |  | € 85.00 |
October 03, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  | 135,485 |
Average exercise price warrants |  | € 14.86 |
Closing share price on date of capital increase |  | € 94.32 |
November 23, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares |  | 30,800 |
Average exercise price warrants |  | € 12.40 |
Closing share price on date of capital increase |  | € 88.90 |
March 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares | 149,370 |  |
Average exercise price warrants | € 23.30 |  |
Closing share price on date of capital increase | € 90.32 |  |
June 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares | 208,310 |  |
Average exercise price warrants | € 20.76 |  |
Closing share price on date of capital increase | € 113.55 |  |
August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Issue of shares | 6,828,985 |  |
September 19, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares | 301,745 |  |
Average exercise price warrants | € 22.12 |  |
Closing share price on date of capital increase | € 145.25 |  |
November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares | 2,617,791 |  |
Average exercise price warrants | € 140.59 |  |
Closing share price on date of capital increase | € 170.75 |  |
November 25, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares | 95,180 |  |
Average exercise price warrants | € 28.23 |  |
Closing share price on date of capital increase | € 172.95 |  |
Share capital. |  |  |
Disclosure of classes of share capital [line items] |  |  |
Balance at beginning of period | € 236,540,000 | € 233,414,000 | € 223,928,000
Net issue of equity | 36,945,000 | 16,021,000 | 23,331,000
Exercise of warrants | 4,082,000 | 3,069,000 | 1,992,000
Balance at end of period | 287,282,000 | 236,540,000 | 233,414,000
Share capital. | April 6, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 1,337,000
Share capital. | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Underwriter discounts and offering expenses (paid) |  |  | (15,790,000)
Offering expenses still to be paid |  |  | (47,000)
Share capital. | June 20, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 281,000
Share capital. | September 21, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 152,000
Share capital. | November 23, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 222,000
Share capital. | March 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 1,613,000 |
Share capital. | June 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 556,000 |
Share capital. | October 03, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 733,000 |
Share capital. | November 23, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 167,000 |
Share capital. | March 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 808,000 |  |
Share capital. | June 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 1,127,000 |  |
Share capital. | August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity | 32,498,000 |  |
Underwriter discounts and offering expenses (paid) | (4,447,000) |  |
Share capital. | September 19, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 1,632,000 |  |
Share capital. | November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 14,162,000 |  |
Share capital. | November 25, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 515,000 |  |
Share premium account |  |  |
Disclosure of classes of share capital [line items] |  |  |
Balance at beginning of period | 1,277,780,000 | 993,025,000 | 649,135,000
Net issue of equity | 923,142,000 | 280,167,000 | 340,593,000
Exercise of warrants | 13,085,000 | 4,588,000 | 3,296,000
Balance at end of period | 2,703,583,000 | 1,277,780,000 | 993,025,000
Share premium account | April 6, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 2,697,000
Share premium account | June 20, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 350,000
Share premium account | September 21, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 117,000
Share premium account | November 23, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 132,000
Share premium account | March 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 2,311,000 |
Share premium account | June 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 781,000 |
Share premium account | October 03, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 1,281,000 |
Share premium account | November 23, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 215,000 |
Share premium account | March 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 2,673,000 |  |
Share premium account | June 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 3,198,000 |  |
Share premium account | August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity | 979,891,000 |  |
Derecognition of Financial Liability | 56,749,000 |  |
Share premium account | September 19, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 5,043,000 |  |
Share premium account | November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 432,826,000 |  |
Derecognition of Financial Liability | 78,953,000 |  |
Share premium account | November 25, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 2,172,000 |  |
Share capital and share premium |  |  |
Disclosure of classes of share capital [line items] |  |  |
Balance at beginning of period | 1,514,320,000 | 1,226,439,000 | 873,063,000
Balance at end of period | 2,911,912,000 | 1,514,320,000 | 1,226,439,000
Share capital and share premium | April 6, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 4,034,000
Share capital and share premium | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Underwriter discounts and offering expenses (paid) |  |  | (15,790,000)
Offering expenses still to be paid |  |  | (47,000)
Share capital and share premium | June 20, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 632,000
Share capital and share premium | September 21, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | 269,000
Share capital and share premium | November 23, 2017 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  |  | € 354,000
Share capital and share premium | March 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 3,924,000 |
Share capital and share premium | June 20, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 1,337,000 |
Share capital and share premium | October 03, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | 2,014,000 |
Share capital and share premium | November 23, 2018 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants |  | € 382,000 |
Share capital and share premium | March 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 3,481,000 |  |
Share capital and share premium | June 20, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 4,325,000 |  |
Share capital and share premium | August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity | 1,012,389,000 |  |
Underwriter discounts and offering expenses (paid) | (4,447,000) |  |
Derecognition of Financial Liability | 56,749,000 |  |
Share capital and share premium | September 19, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 6,675,000 |  |
Share capital and share premium | November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 368,035,000 |  |
Share capital and share premium | November 25, 2019 : exercise of warrants |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | € 2,687,000 |  |
Ordinary Shares |  |  |
Disclosure of classes of share capital [line items] |  |  |
Par value of shares | € 5.41 |  |
Ordinary Shares | August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Issue of shares | 6,828,985 |  |
Closing share price on date of capital increase | € 148.90 |  |
Ordinary Shares | Share capital. | August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity | € 36,945,000 |  |
Ordinary Shares | Share premium account | August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity | 923,142,000 |  |
Ordinary Shares | Share capital and share premium | August 23, 2019 : share subscription by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity | € 960,087,000 |  |
American Depositary Receipts |  |  |
Disclosure of classes of share capital [line items] |  |  |
Issue of shares |  | 2,961,373 |
American Depositary Receipts | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Issue of shares |  |  | 4,312,500
Closing share price on date of capital increase |  |  | € 81.34
American Depositary Receipts | Share capital. |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  | € 16,021,000 |
American Depositary Receipts | Share capital. | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  |  | € 23,331,000
American Depositary Receipts | Share premium account |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  | 280,167,000 |
American Depositary Receipts | Share premium account | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  |  | 340,593,000
American Depositary Receipts | Share capital and share premium |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  | € 296,188,000 |
American Depositary Receipts | Share capital and share premium | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  |  | € 363,924,000
U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Issue of shares |  | 2,961,373 |
Closing share price on date of capital increase |  | € 99.68 |
U.S. public offering | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Issue of shares |  |  | 4,312,500
U.S. public offering | Share capital. |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  | € 57,000 |
Underwriter discounts and offering expenses (paid) |  | (15,964,000) |
U.S. public offering | Share capital. | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  |  | € 7,494,000
U.S. public offering | Share premium account |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  | 280,167,000 |
U.S. public offering | Share premium account | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  |  | 340,593,000
U.S. public offering | Share capital and share premium |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  | 280,224,000 |
Underwriter discounts and offering expenses (paid) |  | € (15,964,000) |
U.S. public offering | Share capital and share premium | April 21, 2017 : U.S. public offering |  |  |
Disclosure of classes of share capital [line items] |  |  |
Net issue of equity |  |  | € 348,087,000
Warrants | November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants, shares | 2,617,791 |  |
Warrants | Share capital. | November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | € 14,162,000 |  |
Warrants | Share premium account | November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | 353,873,000 |  |
Warrants | Share capital and share premium | November 6, 2019 : exercise of warrant A by Gilead |  |  |
Disclosure of classes of share capital [line items] |  |  |
Exercise of warrants | € 368,035,000 |  |

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