Income Taxes	9 Months Ended
Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company is subject to United States federal, state, and foreign income taxes. For the three and nine months ended September 30, 2017, the Company recorded a benefit from income taxes of $125.9 million and $117.6 million, respectively, which included a benefit of $120.2 million and $111.7 million, respectively, related to the Company’s VIEs’ income tax provision. The VIEs’ benefit from income taxes during the the three and nine months ended September 30, 2017 related primarily to the impairment of Parion’s pulmonary ENaC platform and decrease in the fair value of the contingent payments payable by the Company to Parion. The Company has no liability for taxes payable by the Company’s VIEs and the income tax provision and related liability have been allocated to noncontrolling interest. For the three and nine months ended September 30, 2016, the Company recorded a provision for income taxes of $0.5 million and $24.1 million, respectively, which included a benefit of $0.5 million and a provision of $20.1 million, respectively, related to the Company’s VIEs’ income tax provision. As of September 30, 2017 and December 31, 2016, the Company did not have unrecognized tax benefits. The Company recognizes interest and penalties related to income taxes as a component of income tax expense. As of September 30, 2017, no interest and penalties have been accrued. The Company does not expect that its unrecognized tax benefits will materially increase within the next twelve months. The Company did not recognize any material interest or penalties related to uncertain tax positions as of September 30, 2017 and December 31, 2016. The Company continues to maintain a valuation allowance on the majority of its net operating losses and other deferred tax assets because it has a history of cumulative losses. Accordingly, the Company has not reported any tax benefit relating to the remaining net operating loss carryforwards (NOLs) and income tax credit carryforwards that will be utilized in future periods in these jurisdictions. The Company’s U.S. federal net operating loss carryforwards totaled approximately $4.1 billion as of December 31, 2016. On a quarterly basis, the Company reassesses the valuation allowance on its deferred income tax assets weighing positive and negative evidence to assess the recoverability of the deferred tax assets. Based on the Company’s recent financial performance and its future projections, it could record a reversal of all, or a portion of the valuation allowance associated with U.S. deferred tax assets in future periods. However, any such change is subject to actual performance and other considerations that may present positive or negative evidence at the time of the assessment. The Company’s total deferred tax asset balance subject to the valuation allowance was approximately $1.7 billion at December 31, 2016. As described in Note A, “Basis of Presentation and Accounting Policies”, the Company adopted amended guidance, during the nine month period ended September 30, 2017. The amended guidance eliminates the requirement that excess tax benefits be realized as a reduction in current taxes payable before the associated tax benefit can be recognized as an increase in additional paid-in capital and requires excess tax benefits and tax deficiencies to be recorded in the condensed consolidated statement of operations when the awards vest or are settled. Amendments related to accounting for excess tax benefits have been adopted prospectively, resulting in a tax benefit of $31.4 million and $62.2 million for the three and nine months ended September 30, 2017, respectively. In connection with the adoption of this new standard, the Company recorded a cumulative-effect adjustment of $410.8 million as of January 1, 2017 to accumulated deficit and deferred tax assets, with an equal offsetting adjustment to the Company’s valuation allowance. In addition, the Company has recorded $9.4 million related to the impact from adoption of the provisions related to forfeiture rates to accumulated deficit. This change also increased the Company’s deferred tax assets by $3.4 million that is offset by an increase to the valuation allowance in the same amount. The Company files United States federal income tax returns and income tax returns in various state, local and foreign jurisdictions. The Company is no longer subject to any tax assessment from an income tax examination in the United States or any other major taxing jurisdiction for years before 2011, except where the Company has net operating losses or tax credit carryforwards that originate before 2011. The Company currently is under examination by the Canada Revenue Agency for the years ending December 31, 2011 through December 31, 2013. No adjustments have been reported. At September 30, 2017, foreign earnings, which were not significant, have been retained indefinitely by foreign subsidiary companies for reinvestment; therefore, no provision has been made for income taxes that would be payable upon the distribution of such earnings, and it would not be practicable to determine the amount of the related unrecognized deferred income tax liability. Upon repatriation of those earnings, in the form of dividends or otherwise, the Company would be subject to United States federal income taxes (subject to an adjustment for foreign tax credits) and withholding taxes payable to the various foreign countries.

Income Taxes

The Company is subject to United States federal, state, and foreign income taxes. For the three and nine months ended September 30, 2017, the Company recorded a benefit from income taxes of $125.9 million and $117.6 million, respectively, which included a benefit of $120.2 million and $111.7 million, respectively, related to the Company’s VIEs’ income tax provision. The VIEs’ benefit from income taxes during the the three and nine months ended September 30, 2017 related primarily to the impairment of Parion’s pulmonary ENaC platform and decrease in the fair value of the contingent payments payable by the Company to Parion. The Company has no liability for taxes payable by the Company’s VIEs and the income tax provision and related liability have been allocated to noncontrolling interest. For the three and nine months ended September 30, 2016, the Company recorded a provision for income taxes of $0.5 million and $24.1 million, respectively, which included a benefit of $0.5 million and a provision of $20.1 million, respectively, related to the Company’s VIEs’ income tax provision.

As of September 30, 2017 and December 31, 2016, the Company did not have unrecognized tax benefits. The Company recognizes interest and penalties related to income taxes as a component of income tax expense. As of September 30, 2017, no interest and penalties have been accrued. The Company does not expect that its unrecognized tax benefits will materially increase within the next twelve months. The Company did not recognize any material interest or penalties related to uncertain tax positions as of September 30, 2017 and December 31, 2016.

The Company continues to maintain a valuation allowance on the majority of its net operating losses and other deferred tax assets because it has a history of cumulative losses. Accordingly, the Company has not reported any tax benefit relating to the remaining net operating loss carryforwards (NOLs) and income tax credit carryforwards that will be utilized in future periods in these jurisdictions. The Company’s U.S. federal net operating loss carryforwards totaled approximately $4.1 billion as of December 31, 2016. On a quarterly basis, the Company reassesses the valuation allowance on its deferred income tax assets weighing positive and negative evidence to assess the recoverability of the deferred tax assets. Based on the Company’s recent financial performance and its future projections, it could record a reversal of all, or a portion of the valuation allowance associated with U.S. deferred tax assets in future periods. However, any such change is subject to actual performance and other considerations that may present positive or negative evidence at the time of the assessment. The Company’s total deferred tax asset balance subject to the valuation allowance was approximately $1.7 billion at December 31, 2016.

As described in Note A, “Basis of Presentation and Accounting Policies”, the Company adopted amended guidance, during the nine month period ended September 30, 2017. The amended guidance eliminates the requirement that excess tax benefits be realized as a reduction in current taxes payable before the associated tax benefit can be recognized as an increase in additional paid-in capital and requires excess tax benefits and tax deficiencies to be recorded in the condensed consolidated statement of operations when the awards vest or are settled. Amendments related to accounting for excess tax benefits have been adopted prospectively, resulting in a tax benefit of $31.4 million and $62.2 million for the three and nine months ended September 30, 2017, respectively. In connection with the adoption of this new standard, the Company recorded a cumulative-effect adjustment of $410.8 million as of January 1, 2017 to accumulated deficit and deferred tax assets, with an equal offsetting adjustment to the Company’s valuation allowance. In addition, the Company has recorded $9.4 million related to the impact from adoption of the provisions related to forfeiture rates to accumulated deficit. This change also increased the Company’s deferred tax assets by $3.4 million that is offset by an increase to the valuation allowance in the same amount.

The Company files United States federal income tax returns and income tax returns in various state, local and foreign jurisdictions. The Company is no longer subject to any tax assessment from an income tax examination in the United States or any other major taxing jurisdiction for years before 2011, except where the Company has net operating losses or tax credit carryforwards that originate before 2011. The Company currently is under examination by the Canada Revenue Agency for the years ending December 31, 2011 through December 31, 2013. No adjustments have been reported.

At September 30, 2017, foreign earnings, which were not significant, have been retained indefinitely by foreign subsidiary companies for reinvestment; therefore, no provision has been made for income taxes that would be payable upon the distribution of such earnings, and it would not be practicable to determine the amount of the related unrecognized deferred income tax liability. Upon repatriation of those earnings, in the form of dividends or otherwise, the Company would be subject to United States federal income taxes (subject to an adjustment for foreign tax credits) and withholding taxes payable to the various foreign countries.