Subsequent Events	9 Months Ended
Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events TriVascular Merger On October 26, 2015, the Company entered into an agreement and plan of merger (the “Merger Agreement”), with TriVascular Technologies, Inc. (“TriVascular”) under which the Company agreed to acquire all of TriVascular’s outstanding capital stock through a merger of a direct wholly-owned subsidiary of the Company (“Merger Sub”) with and into TriVascular (the “TriVascular Merger”). TriVascular will survive the TriVascular Merger and become a wholly-owned subsidiary of the Company. Under the terms and conditions of the Merger Agreement, at the effective time of the TriVascular Merger, all outstanding shares of capital stock of TriVascular will be cancelled and converted into the right to receive merger consideration with a value, based on the closing price of the Company’s common stock on October 23, 2015, equal to up to approximately $211 million at closing, subject to certain adjustments specified in the Merger Agreement (the “Merger Consideration”). Approximately $187 million of the Merger Consideration payable to TriVascular stockholders will be payable in shares of the Company’s common stock issued at closing. This represents the value of 19.999% of the Company’s common stock as of October 23, 2015. Subject to certain adjustments specified in the Merger Agreement, up to the remaining approximately $24 million of the Merger Consideration will be payable in cash at closing. The Merger Agreement includes customary representations, warranties and covenants of the Company, TriVascular and Merger Sub. The Merger Agreement contains customary closing conditions, including the requisite consent to the adoption of the Merger Agreement by TriVascular’s stockholders and the expiration or termination of the waiting period (and any extension thereof) under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. The consummation of the TriVascular Merger is not subject to a financing condition. The Merger Agreement also includes customary termination provisions for both TriVascular and the Company, subject, in certain circumstances, to the payment by TriVascular or the Company of a termination fee of 3.0% or 4.5%, respectively, of the aggregate purchase price. TriVascular must pay the Company the 3.0% termination fee following a change of recommendation by the board of directors of TriVascular or if TriVascular terminates the Merger Agreement to enter into an agreement with respect to a proposal from a third party that the board of directors of TriVascular has determined in good faith in the exercise of its fiduciary duties is superior to the Company’s, in each case, as is described in further detail in the Merger Agreement. The Company must pay TriVascular the 4.5% termination fee if the Company is unable to obtain antitrust approval of the merger. 3.25% Convertible Senior Notes On October 27, 2015, the Company entered into an underwriting agreement with respect to the offer and sale of $110 million aggregate principal amount of 3.25% Convertible Senior Notes due 2020 (the “3.25% Convertible Senior Notes”). The 3.25% Convertible Senior Notes bear interest at a rate of 3.25% per year, payable semi-annually on May 1 and November 1 of each year, commencing May 1, 2016. The 3.25% Convertible Senior Notes will mature on November 1, 2020, unless earlier purchased, redeemed or converted in accordance with the terms of the 3.25% Convertible Senior Notes. The indenture governing 3.25% Convertible Senior Notes will contain customary terms and covenants and events of default. The initial conversion rate of the 3.25% Convertible Senior Notes is 89.4314 shares of the Company’s common stock per $1,000 principal amount of 3.25% Convertible Senior Notes (which is equivalent to an initial conversion price of approximately $11.18 per share). The conversion rate is subject to adjustment upon the occurrence of certain specified events. Prior to August 1, 2020, the 3.25% Convertible Senior Notes will be convertible only upon the occurrence of certain events and during certain periods, and thereafter, at any time until the second scheduled trading day immediately preceding the maturity date. On or after November 1, 2018, the Company may redeem for cash all or any portion of the 3.25% Convertible Senior Notes, at the Company’s option, but only if the closing sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on, and including, the second trading day immediately preceding the date on which the Company provide notice of redemption, exceeds 130% of the conversion price on each applicable trading day. The redemption price will equal 100% of the principal amount of the 3.25% Convertible Senior Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date.

Subsequent Events

TriVascular Merger

On October 26, 2015, the Company entered into an agreement and plan of merger (the “Merger Agreement”), with TriVascular Technologies, Inc. (“TriVascular”) under which the Company agreed to acquire all of TriVascular’s outstanding capital stock through a merger of a direct wholly-owned subsidiary of the Company (“Merger Sub”) with and into TriVascular (the “TriVascular Merger”). TriVascular will survive the TriVascular Merger and become a wholly-owned subsidiary of the Company.

Under the terms and conditions of the Merger Agreement, at the effective time of the TriVascular Merger, all outstanding shares of capital stock of TriVascular will be cancelled and converted into the right to receive merger consideration with a value, based on the closing price of the Company’s common stock on October 23, 2015, equal to up to approximately $211 million at closing, subject to certain adjustments specified in the Merger Agreement (the “Merger Consideration”). Approximately $187 million of the Merger Consideration payable to TriVascular stockholders will be payable in shares of the Company’s common stock issued at closing. This represents the value of 19.999% of the Company’s common stock as of October 23, 2015. Subject to certain adjustments specified in the Merger Agreement, up to the remaining approximately $24 million of the Merger Consideration will be payable in cash at closing.

The Merger Agreement includes customary representations, warranties and covenants of the Company, TriVascular and Merger Sub. The Merger Agreement contains customary closing conditions, including the requisite consent to the adoption of the Merger Agreement by TriVascular’s stockholders and the expiration or termination of the waiting period (and any extension thereof) under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. The consummation of the TriVascular Merger is not subject to a financing condition.

The Merger Agreement also includes customary termination provisions for both TriVascular and the Company, subject, in certain circumstances, to the payment by TriVascular or the Company of a termination fee of 3.0% or 4.5%, respectively, of the aggregate purchase price. TriVascular must pay the Company the 3.0% termination fee following a change of recommendation by the board of directors of TriVascular or if TriVascular terminates the Merger Agreement to enter into an agreement with respect to a proposal from a third party that the board of directors of TriVascular has determined in good faith in the exercise of its fiduciary duties is superior to the Company’s, in each case, as is described in further detail in the Merger Agreement. The Company must pay TriVascular the 4.5% termination fee if the Company is unable to obtain antitrust approval of the merger.

3.25% Convertible Senior Notes

On October 27, 2015, the Company entered into an underwriting agreement with respect to the offer and sale of $110 million aggregate principal amount of 3.25% Convertible Senior Notes due 2020 (the “3.25% Convertible Senior Notes”). The 3.25% Convertible Senior Notes bear interest at a rate of 3.25% per year, payable semi-annually on May 1 and November 1 of each year, commencing May 1, 2016. The 3.25% Convertible Senior Notes will mature on November 1, 2020, unless earlier purchased, redeemed or converted in accordance with the terms of the 3.25% Convertible Senior Notes. The indenture governing 3.25% Convertible Senior Notes will contain customary terms and covenants and events of default. The initial conversion rate of the 3.25% Convertible Senior Notes is 89.4314 shares of the Company’s common stock per $1,000 principal amount of 3.25% Convertible Senior Notes (which is equivalent to an initial conversion price of approximately $11.18 per share). The conversion rate is subject to adjustment upon the occurrence of certain specified events. Prior to August 1, 2020, the 3.25% Convertible Senior Notes will be convertible only upon the occurrence of certain events and during certain periods, and thereafter, at any time until the second scheduled trading day immediately preceding the maturity date. On or after November 1, 2018, the Company may redeem for cash all or any portion of the 3.25% Convertible Senior Notes, at the Company’s option, but only if the closing sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on, and including, the second trading day immediately preceding the date on which the Company provide notice of redemption, exceeds 130% of the conversion price on each applicable trading day. The redemption price will equal 100% of the principal amount of the 3.25% Convertible Senior Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date.