XML 48 R28.htm IDEA: XBRL DOCUMENT
v3.20.4

Unsecured Convertible Senior Notes (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2020
Debt Instrument [Line Items] |
Summary of unsecured convertible senior notes outstanding | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Balance as of December 31, 2020
​ |  | 2023 Notes |  | 2026 Notes |  | Total
​ | ​ | (In thousands)
Principal amount | ​ | $ | 95,000 | ​ | $ | 225,030 | ​ | $ | 320,030
Unamortized discount | ​ |  | (17,101) | ​ |  | (60,544) | ​ |  | (77,645)
Unamortized issuance costs attributable to liability component | ​ |  | (1,481) | ​ |  | (4,616) | ​ |  | (6,097)
Total Convertible Senior Notes, net | ​ | $ | 76,418 | ​ | $ | 159,870 | ​ | $ | 236,288
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Fair value of outstanding Convertible Senior Notes (1) | ​ | $ | 101,769 | ​ | $ | 246,779 | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Amount by which the Convertible Senior Notes if-converted value exceeds their principal amount | ​ | $ | 6,769 | ​ | $ | 21,749 | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Equity component | ​ | $ | 25,854 | ​ | $ | 63,544 | ​ | ​ | ​
Issuance costs | ​ |  | (837) | ​ |  | (1,916) | ​ | ​ | ​
Net carrying amount of equity component (2) | ​ | $ | 25,017 | ​ | $ | 61,628 | ​ | ​ | ​
​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Balance as of | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | December 31, 2019 | ​ | ​ | ​ | ​ | ​ | ​
​ |  | 2023 Notes |  | ​ | ​ |  | ​ | ​
​ | ​ | (In thousands) | ​ | ​ | ​ | ​ | ​ | ​
Principal amount | ​ | $ | 210,000 | ​ | ​ | ​ | ​ | ​ | ​
Unamortized discount | ​ |  | (47,660) | ​ | ​ | ​ | ​ | ​ | ​
Unamortized issuance costs attributable to liability component | ​ |  | (4,127) | ​ | ​ | ​ | ​ | ​ | ​
Total Convertible Senior Notes, net | ​ | $ | 158,213 | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Fair value of outstanding Convertible Senior Notes (1) | ​ | $ | 208,163 | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Amount by which the Convertible Senior Notes if-converted value exceeds their principal amount | ​ | $ | — | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Equity component | ​ | $ | 57,152 | ​ | ​ | ​ | ​ | ​ | ​
Issuance costs | ​ |  | (1,851) | ​ | ​ | ​ | ​ | ​ | ​
Net carrying amount of equity component (2) | ​ | $ | 55,301 | ​ | ​ | ​ | ​ | ​ | ​
(1) | The fair value is classified as Level 3 due to the limited trading activity for the unsecured convertible senior notes.
(2) | Included in the consolidated balance sheet within additional paid-in capital.
Schedule of future minimum payments of debt | ​
​ | ​ | ​ | ​
​ |  | (In thousands)
2021 | ​ | $ | —
2022 |  | ​ | —
2023 |  | ​ | 95,000
2024 |  | ​ | —
2025 |  | ​ | —
2026 |  | ​ | 225,030
Total future minimum payments under the convertible senior notes |  | $ | 320,030
2023 Convertible Senior Notes |
Debt Instrument [Line Items] |
Summary of issuance of the notes and use of proceeds | ​
​ | ​ | ​ | ​
​ |  | (In thousands)
2023 Notes principal amount issued | ​ | $ | 210,000
Repayment of previously outstanding note payable (see "Note 7--Debt") | ​ |  | (146,046)
Purchase of 2023 Capped Call | ​ |  | (33,180)
Issuance costs | ​ |  | (6,800)
Net proceeds available for corporate use | ​ | $ | 23,974
Schedule of total interest expense recognized | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Year Ended December 31,
​ |  | 2020 |  | 2019 |  | 2018
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Contractual interest expense | ​ | $ | 10,410 | ​ | $ | 13,089 | ​ | $ | 1,677
Amortization of debt issuance costs | ​ |  | 669 | ​ |  | 8,496 | ​ |  | 996
Amortization of debt discount | ​ |  | 7,728 | ​ |  | 736 | ​ |  | 86
Total | ​ | $ | 18,807 | ​ | $ | 22,321 | ​ | $ | 2,759
2026 Convertible Senior Notes |
Debt Instrument [Line Items] |
Summary of issuance of the notes and use of proceeds | ​
​ | ​ | ​ | ​
​ |  | (In thousands)
2026 Notes principal amount issued | ​ | $ | 225,030
Repurchase of 2023 Notes | ​ |  | (125,638)
Purchase of 2026 Capped Call | ​ |  | (23,223)
Termination of the 2023 Capped Call contracts related to debt repurchased | ​ |  | 7,549
Issuance costs | ​ |  | (6,785)
Net proceeds available for corporate use | ​ | $ | 76,933
Schedule of total interest expense recognized | ​
​ | ​ | ​ | ​
​ |  | ​
​ | ​ | Year Ended
​ | ​ | December 31, 2020
​ | ​ | (In thousands)
Contractual interest expense | ​ | $ | 4,397
Amortization of debt issuance costs | ​ |  | 230
Amortization of debt discount | ​ |  | 3,022
Total | ​ | $ | 7,649

X
- Definition Tabular disclosure of interest expense recognized relating to debt instrument. + References No definition available. + Details
Name: | omer_ScheduleOfDebtInstrumentInterestExpenseRecognizedTableTextBlock
Namespace Prefix: | omer_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of issuance of the notes and use of proceeds of debt instrument. + References No definition available. + Details
Name: | omer_ScheduleOfDebtInstrumentIssuanceAndUseOfProceedsTableTextBlock
Namespace Prefix: | omer_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of borrowings which can be exchanged for a specified number of another security at the option of the issuer or the holder. Disclosures include, but are not limited to, principal amount, amortized premium or discount, and amount of liability and equity components. + References No definition available. + Details
Name: | us-gaap_ConvertibleDebtTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturity and sinking fund requirement for long-term debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
Name: | us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=omer_ConvertibleSeniorNotes2023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=omer_ConvertibleSeniorNotes2026Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |