Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation The condensed consolidated financial statements contained in this report are unaudited. In the opinion of management, the condensed consolidated financial statements include all adjustments, which are of a normal recurring nature, necessary to present fairly the financial position at March 31, 2021, and the results of operations and cash flows for the three-month periods ended March 31, 2021 and 2020. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, the accompanying unaudited condensed consolidated financial statements should be read in conjunction with the notes to the audited consolidated financial statements contained in the Company’s Form 10-K for the year ended December 31, 2020, as filed with the Securities and Exchange Commission on May 4, 2021. Reverse Stock Split On May 28, 2020, the Company effectuated a one-for-ten reverse stock split of its outstanding shares of common stock (the "Reverse Stock Split"). The Reverse Stock Split reduces the Company's shares of outstanding common stock and stock options. Fractional shares of Common Stock that would have otherwise resulted from the Reverse Stock Split were rounded up to the nearest whole share. All share and per share data for all periods presented in the accompanying Condensed Consolidated Financial Statements and the related disclosures have been adjusted retroactively to reflect the Reverse Stock Split. The number of authorized shares of common stock and the par value per share remains unchanged. Principles of Consolidation The condensed consolidated financial statements include the accounts of Teligent, Inc. and its wholly owned and majority-owned subsidiaries. The Company consolidated the following entities: Igen, Inc., Teligent Pharma. Inc., Teligent Luxembourg S.à.r.l., Teligent OÜ, and Teligent Canada Inc., in addition to the following inactive entities: Microburst Energy, Inc., Blood Cells, Inc. and Flavorsome, Ltd. All inter-company accounts and transactions have been eliminated.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates include the valuation of derivative liabilities associated with certain Notes and the Senior Credit Facility, sales returns and allowances, allowances for excess and obsolete inventories, allowances for doubtful accounts, provisions for income taxes and related valuation allowances, stock based compensation, the assessment for the impairment of long-lived assets (including property, plant and equipment), indefinite-lived assets (including, goodwill, intangibles, and In-Process research and development), and legal accruals for environmental cleanup and remediation costs. The Company bases its estimates and assumptions on historical experience, known or expected trends and various other assumptions that it believes to be reasonable. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates.
Cash Equivalents	Cash Equivalents The Company considers all highly liquid instruments purchased with the original maturity of three months or less to be cash equivalents to the extent the funds are not being held for investment purposes. Cash and cash equivalents include cash on hand and bank demand deposits used in the Company’s cash management program. The Company has restricted cash, consisting of escrow accounts and letter of credits, which are included within other long-term assets on the Condensed Consolidated Balance Sheet. Pursuant to the New Credit Facilities agreement, proceeds from the 2023 Term Loan were deposited in a blocked bank account and restricted for use for the sole purpose of repurchasing the outstanding 2019 Notes.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, trade receivables, restricted cash, accounts payable and other accrued liabilities at March 31, 2021 approximate their fair value for all periods presented. The Company measures fair value in accordance with ASC 820-10, “Fair Value Measurements and Disclosures”. ASC 820-10 clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. As a basis for considering such assumptions, ASC 820-10 establishes a three-tier value hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value: Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.
Loss Per Common Share	Income/(Loss) Per Common Share Basic income/(loss) per share of common stock is computed based on the weighted average number of shares of common stock outstanding during the period. Diluted income/(loss) per share of common stock is computed using the weighted average number of shares of common stock and potentially dilutive common stock equivalents outstanding during the period. Potential dilutive common stock equivalents include shares issuable upon the conversion of the notes and the exercise of options and warrants.
Concentration of Credit Risk	Concentration of Credit Risk Major customers of the Company are defined as those constituting greater than 10% of the Company's total revenue.
Recently Adopted Accounting Pronouncements/Recently Issued Not Yet Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU No. 2020-04”). The update provides optional guidance for a limited period to ease the potential burden in accounting for (or recognizing the effects of) contract modifications on financial reporting caused by reference rate reform. ASU 2020-04 is effective for all entities as of March 12, 2020 through December 31, 2022. The Company adopted this guidance in the second quarter of 2020. The adoption of this guidance had no impact on the Company's Condensed Consolidated Financial Statements or the related disclosures. In December 2019, the FASB issued an accounting standard update to simplify the accounting for income taxes. The standard’s amendments include changes in various subtopics of accounting for income taxes including, but not limited to, accounting for “hybrid” tax regimes, tax basis step-up in goodwill obtained in a transaction that is not a business combination, intraperiod tax allocation exception to an incremental approach, ownership changes in investments, interim-period accounting for enacted changes in tax law, and year-to-date loss limitation in interim-period tax accounting. The guidance is effective for fiscal years beginning after December 15, 2020 with early adoption permitted, including the interim periods within those years. The Company has implemented the guidance on the Company’s Condensed Consolidated Financial Statements and related disclosures in the enclosed statements. Recently Issued Not Yet Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06 (“ASU 2020-06”) “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity.” ASU 2020-06 simplifies the accounting for convertible instruments by reducing the number of accounting models for convertible debt instruments and convertible preferred stock. Limiting the accounting models results in fewer embedded conversion features being separately recognized from the host contract as compared with current GAAP. Convertible instruments that continue to be subject to separation models are (1) those with embedded conversion features that are not clearly and closely related to the host contract, that meet the definition of a derivative, and that do not qualify for a scope exception from derivative accounting and (2) convertible debt instruments issued with substantial premiums for which the premiums are recorded as paid-in capital. In addition, ASU 2020-06 amends the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. The Amendments also affects the diluted EPS calculation for instruments that may be settled in cash or shares and for convertible instruments. The amendments are effective for public entities excluding smaller reporting companies for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. The Company is evaluating the impact this guidance will have on its Condensed Consolidated Financial Statements and related disclosures upon adoption effective January 1, 2024. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU No. 2016-13”), which requires that a financial asset (or a group of financial assets) measured at an amortized cost basis be presented at the net amount expected to be collected. This approach to estimating credit losses applies to most financial assets measured at amortized cost and certain other instruments, including but not limited to, trade and other receivables. The amendments in this update are initially effective for public business entities for fiscal years beginning after December 15, 2019. The Financial Accounting Standards Board subsequently postponed the effective date for small reporting companies to January 2023, which for the Company means January 1, 2023. Based on the current status of the evaluation, the Company believes the adoption of the guidance will not have a material impact on its Condensed Consolidated Financial Statements and related disclosures. The Company expects to continue and finalize its evaluation and assessment as required by the guidance upon adoption.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2021

Basis of Presentation and Principles of Consolidation

Basis of Presentation

The condensed consolidated financial statements contained in this report are unaudited. In the opinion of management, the condensed consolidated financial statements include all adjustments, which are of a normal recurring nature, necessary to present fairly the financial position at March 31, 2021, and the results of operations and cash flows for the three-month periods ended March 31, 2021 and 2020. Certain information and disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, the accompanying unaudited condensed consolidated financial statements should be read in conjunction with the notes to the audited consolidated financial statements contained in the Company’s Form 10-K for the year ended December 31, 2020, as filed with the Securities and Exchange Commission on May 4, 2021.

Reverse Stock Split

On May 28, 2020, the Company effectuated a one-for-ten reverse stock split of its outstanding shares of common stock (the "Reverse Stock Split"). The Reverse Stock Split reduces the Company's shares of outstanding common stock and stock options. Fractional shares of Common Stock that would have otherwise resulted from the Reverse Stock Split were rounded up to the nearest whole share. All share and per share data for all periods presented in the accompanying Condensed Consolidated Financial Statements and the related disclosures have been adjusted retroactively to reflect the Reverse Stock Split. The number of authorized shares of common stock and the par value per share remains unchanged.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of Teligent, Inc. and its wholly owned and majority-owned subsidiaries. The Company consolidated the following entities: Igen, Inc., Teligent Pharma. Inc., Teligent Luxembourg S.à.r.l., Teligent OÜ, and Teligent Canada Inc., in addition to the following inactive entities: Microburst Energy, Inc., Blood Cells, Inc. and Flavorsome, Ltd. All inter-company accounts and transactions have been eliminated.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates include the valuation of derivative liabilities associated with certain Notes and the Senior Credit Facility, sales returns and allowances, allowances for excess and obsolete inventories, allowances for doubtful accounts, provisions for income taxes and related valuation allowances, stock based compensation, the assessment for the impairment of long-lived assets (including property, plant and equipment), indefinite-lived assets (including, goodwill, intangibles, and In-Process research and development), and legal accruals for environmental cleanup and remediation costs. The Company bases its estimates and assumptions on historical experience, known or expected trends and various other assumptions that it believes to be reasonable. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates.

Cash Equivalents

The Company considers all highly liquid instruments purchased with the original maturity of three months or less to be cash equivalents to the extent the funds are not being held for investment purposes. Cash and cash equivalents include cash on hand and bank demand deposits used in the Company’s cash management program.

The Company has restricted cash, consisting of escrow accounts and letter of credits, which are included within other long-term assets on the Condensed Consolidated Balance Sheet. Pursuant to the New Credit Facilities agreement, proceeds from the 2023 Term Loan were deposited in a blocked bank account and restricted for use for the sole purpose of repurchasing the outstanding 2019 Notes.

Fair Value of Financial Instruments

The carrying amounts of cash and cash equivalents, trade receivables, restricted cash, accounts payable and other accrued liabilities at March 31, 2021 approximate their fair value for all periods presented. The Company measures fair value in accordance with ASC 820-10, “Fair Value Measurements and Disclosures”. ASC 820-10 clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. As a basis for considering such assumptions, ASC 820-10 establishes a three-tier value hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value:

Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date.

Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability.

Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.

Loss Per Common Share

Income/(Loss) Per Common Share

Basic income/(loss) per share of common stock is computed based on the weighted average number of shares of common stock outstanding during the period. Diluted income/(loss) per share of common stock is computed using the weighted average number of shares of common stock and potentially dilutive common stock equivalents outstanding during the period. Potential dilutive common stock equivalents include shares issuable upon the conversion of the notes and the exercise of options and warrants.

Concentration of Credit Risk

Major customers of the Company are defined as those constituting greater than 10% of the Company's total revenue.

Recently Adopted Accounting Pronouncements/Recently Issued Not Yet Adopted Accounting Pronouncements

Recently Adopted Accounting Pronouncements

In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU No. 2020-04”). The update provides optional guidance for a limited period to ease the potential burden in accounting for (or recognizing the effects of) contract modifications on financial reporting caused by reference rate reform. ASU 2020-04 is effective for all entities as of March 12, 2020 through December 31, 2022. The Company adopted this guidance in the second quarter of 2020. The adoption of this guidance had no impact on the Company's Condensed Consolidated Financial Statements or the related disclosures.

In December 2019, the FASB issued an accounting standard update to simplify the accounting for income taxes. The standard’s amendments include changes in various subtopics of accounting for income taxes including, but not limited to, accounting for “hybrid” tax regimes, tax basis step-up in goodwill obtained in a transaction that is not a business combination, intraperiod tax allocation exception to an incremental approach, ownership changes in investments, interim-period accounting for enacted changes in tax law, and year-to-date loss limitation in interim-period tax accounting. The guidance is effective for fiscal years beginning after December 15, 2020 with early adoption permitted, including the interim periods within those years. The Company has implemented the guidance on the Company’s Condensed Consolidated Financial Statements and related disclosures in the enclosed statements.

Recently Issued Not Yet Adopted Accounting Pronouncements

In August 2020, the FASB issued ASU No. 2020-06 (“ASU 2020-06”) “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity.” ASU 2020-06 simplifies the accounting for convertible instruments by reducing the number of accounting models for convertible debt instruments and convertible preferred stock. Limiting the accounting models results in fewer embedded conversion features being separately recognized from the host contract as compared with current GAAP. Convertible instruments that continue to be subject to separation models are (1) those with embedded conversion features that are not clearly and closely related to the host contract, that meet the definition of a derivative, and that do not qualify for a scope exception from derivative accounting and (2) convertible debt instruments issued with substantial premiums for which the premiums are recorded as paid-in capital. In addition, ASU 2020-06 amends the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. The Amendments also affects the diluted EPS calculation for instruments that may be settled in cash or shares and for convertible instruments. The amendments are effective for public entities excluding smaller reporting companies for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. The Company is evaluating the impact this guidance will have on its Condensed Consolidated Financial Statements and related disclosures upon adoption effective January 1, 2024.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU No. 2016-13”), which requires that a financial asset (or a group of financial assets) measured at an amortized cost basis be presented at the net amount expected to be collected. This approach to estimating credit losses applies to most financial assets measured at amortized cost and certain other instruments, including but not limited to, trade and other receivables. The amendments in this update are initially effective for public business entities for fiscal years beginning after December 15, 2019. The Financial Accounting Standards Board subsequently postponed the effective date for small reporting companies to January 2023, which for the Company means January 1, 2023. Based on the current status of the evaluation, the Company believes the adoption of the guidance will not have a material impact on its Condensed Consolidated Financial Statements and related disclosures. The Company expects to continue and finalize its evaluation and assessment as required by the guidance upon adoption.