Long-term debt	12 Months Ended
Dec. 31, 2016
Long-term debt [Abstract]
Long-term debt	9. Long-term debt On January 29, 2014, the Company issued $250.0 million aggregate principal amount of 2.875% Convertible Senior Notes due 2021 (the "Notes"). The Notes bear interest at a rate of 2.875% per year, payable semi-annually in arrears on January 15 and July 15 of each year. The Notes mature on January 15, 2021, unless earlier purchased by the Company or converted. The original conversion rate is equal to 30.8821 shares of common stock per $1,000 principal amount of notes (which is equivalent to a conversion price of approximately $32.38 per share of common stock). The conversion rate is subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. The Company incurred approximately $8.3 million in debt issuance costs associated with the Notes, which has been capitalized on the consolidated balance sheets and is being amortized over seven years. As of August 1, 2016, certain conversion features were triggered due to the completion of the Aptevo spin-off. The conversion rate under the Notes was adjusted in accordance with the terms of the indenture. Effective August 12, 2016, the conversion rate was adjusted to 32.3860 shares of common stock per $1,000 principal amount of notes (which is equivalent to a conversion price of approximately $30.88 per share of common stock). On December 11, 2013, the Company entered into a senior secured credit agreement (the "Credit Agreement") with three lending financial institutions. The Credit Agreement provided for a revolving credit facility of up to $100.0 million through December 11, 2018 (or such earlier date required by the terms of the Credit Agreement). Under the revolving credit facility, the Company is required to pay an unused fee of approximately 0.5% annually, on a quarterly basis. In addition, during the year ended December 31, 2014, the Company expensed $1.8 million of debt issuance cost associated with the term loan facility. As of December 31, 2016 and 2015, no amounts were drawn under the revolving credit facility. The Company's payment obligations under the Credit Agreement are secured by a lien on substantially all of the Company's assets, including the stock of all of the Company's subsidiaries, and the assets of the subsidiary guarantors, including mortgages over certain of their real properties, including the Company's large-scale vaccine manufacturing facility in Lansing, Michigan and the Company's product development and manufacturing facility in Baltimore, Maryland. The Credit Agreement, as amended, contains affirmative and negative covenants customary for financings of this type. Negative covenants in the Credit Agreement limit the Company's ability to, among other things: incur indebtedness (other than the issuance of the Notes) and liens; dispose of assets; make investments including loans, advances or guarantees; and enter into certain mergers or similar transactions. The Credit Agreement also contains financial covenants, tested quarterly and in connection with any triggering events under the Credit Agreement that include the maintenance of: (1) a minimum consolidated debt service coverage ratio of 2.50 to 1.00, (2) a maximum consolidated leverage ratio for the period ending on or prior to September 30, 2014 of 4.00 to 1.00, for the measurement period ending December 31, 2014 of 3.75 to 1.00, and thereafter of 3.50 to 1.00, and (3) a minimum liquidity requirement of $50.0 million. Upon the occurrence and continuance of an event of default under the Credit Agreement, the commitments of the lenders to make loans under the Credit Agreement may be terminated and the Company's payment obligations under the Credit Agreement may be accelerated. The events of default under the Credit Agreement include, among others, subject in some cases to specified cure periods: payment defaults; inaccuracy of representations and warranties in any material respect; defaults in the observance or performance of covenants; bankruptcy and insolvency related defaults; the entry of a final judgment in excess of a threshold amount; change of control; and the invalidity of loan documents relating to the Credit Agreement. The Company was in compliance with these covenants as of December 31, 2016 and 2015. As of December 31, 2015, the Company reclassified debt issuance costs of $1.2 million and $4.9 million from prepaid expenses and other current assets and other assets, respectively, as a reduction to long-term debt as a result of the adoption of ASU No. 2015-03.

9. Long-term debt

On January 29, 2014, the Company issued $250.0 million aggregate principal amount of 2.875% Convertible Senior Notes due 2021 (the "Notes"). The Notes bear interest at a rate of 2.875% per year, payable semi-annually in arrears on January 15 and July 15 of each year. The Notes mature on January 15, 2021, unless earlier purchased by the Company or converted. The original conversion rate is equal to 30.8821 shares of common stock per $1,000 principal amount of notes (which is equivalent to a conversion price of approximately $32.38 per share of common stock). The conversion rate is subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. The Company incurred approximately $8.3 million in debt issuance costs associated with the Notes, which has been capitalized on the consolidated balance sheets and is being amortized over seven years. As of August 1, 2016, certain conversion features were triggered due to the completion of the Aptevo spin-off. The conversion rate under the Notes was adjusted in accordance with the terms of the indenture. Effective August 12, 2016, the conversion rate was adjusted to 32.3860 shares of common stock per $1,000 principal amount of notes (which is equivalent to a conversion price of approximately $30.88 per share of common stock).

On December 11, 2013, the Company entered into a senior secured credit agreement (the "Credit Agreement") with three lending financial institutions. The Credit Agreement provided for a revolving credit facility of up to $100.0 million through December 11, 2018 (or such earlier date required by the terms of the Credit Agreement). Under the revolving credit facility, the Company is required to pay an unused fee of approximately 0.5% annually, on a quarterly basis. In addition, during the year ended December 31, 2014, the Company expensed $1.8 million of debt issuance cost associated with the term loan facility. As of December 31, 2016 and 2015, no amounts were drawn under the revolving credit facility.

The Company's payment obligations under the Credit Agreement are secured by a lien on substantially all of the Company's assets, including the stock of all of the Company's subsidiaries, and the assets of the subsidiary guarantors, including mortgages over certain of their real properties, including the Company's large-scale vaccine manufacturing facility in Lansing, Michigan and the Company's product development and manufacturing facility in Baltimore, Maryland.

The Credit Agreement, as amended, contains affirmative and negative covenants customary for financings of this type. Negative covenants in the Credit Agreement limit the Company's ability to, among other things: incur indebtedness (other than the issuance of the Notes) and liens; dispose of assets; make investments including loans, advances or guarantees; and enter into certain mergers or similar transactions. The Credit Agreement also contains financial covenants, tested quarterly and in connection with any triggering events under the Credit Agreement that include the maintenance of: (1) a minimum consolidated debt service coverage ratio of 2.50 to 1.00, (2) a maximum consolidated leverage ratio for the period ending on or prior to September 30, 2014 of 4.00 to 1.00, for the measurement period ending December 31, 2014 of 3.75 to 1.00, and thereafter of 3.50 to 1.00, and (3) a minimum liquidity requirement of $50.0 million. Upon the occurrence and continuance of an event of default under the Credit Agreement, the commitments of the lenders to make loans under the Credit Agreement may be terminated and the Company's payment obligations under the Credit Agreement may be accelerated. The events of default under the Credit Agreement include, among others, subject in some cases to specified cure periods: payment defaults; inaccuracy of representations and warranties in any material respect; defaults in the observance or performance of covenants; bankruptcy and insolvency related defaults; the entry of a final judgment in excess of a threshold amount; change of control; and the invalidity of loan documents relating to the Credit Agreement. The Company was in compliance with these covenants as of December 31, 2016 and 2015.

As of December 31, 2015, the Company reclassified debt issuance costs of $1.2 million and $4.9 million from prepaid expenses and other current assets and other assets, respectively, as a reduction to long-term debt as a result of the adoption of ASU No. 2015-03.