Restructuring	12 Months Ended
Dec. 31, 2016
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring Acquisition Restructuring In June 2014, the Company discontinued manufacturing MACI in Denmark and temporarily suspended sales of MACI in Europe. Furthermore, the Company eliminated approximately 80 full time employee positions, which represented approximately 30% of the Company’s current total workforce. As a result, the Company recorded a restructuring charge of $3.0 million for the year ended December 31, 2014, related to the operations in the United States and Denmark, primarily representing cash payments for severance and other personnel-related expenses. Of the total restructuring charge, $2.5 million was recorded in cost of product sales, and $0.5 million was recorded in selling, general and administrative expenses. There was no restructuring reserve as of December 31, 2015 or 2016 as a result of cash payments made for severance and other personnel-related expenses. R&D Restructuring Given the expense required to conduct further development and the Company's focus on growing its existing commercial products and becoming profitable, at this time, the Company does not have current plans to initiate or fund a Phase 3 trial related to the ixCELL-DCM study on its own. As a result of no current need to manufacture ixmyelocel-T at the Ann Arbor facility, the Company recorded an asset retirement obligation of $0.2 million related to the suspension of operations in the Ann Arbor cleanroom facility and recorded a severance accrual of $0.1 million in research and development expenses related to this suspension as of December 31, 2016.

Restructuring

12 Months Ended

Dec. 31, 2016

Restructuring and Related Activities [Abstract]

Acquisition Restructuring

In June 2014, the Company discontinued manufacturing MACI in Denmark and temporarily suspended sales of MACI in Europe. Furthermore, the Company eliminated approximately 80 full time employee positions, which represented approximately 30% of the Company’s current total workforce. As a result, the Company recorded a restructuring charge of $3.0 million for the year ended December 31, 2014, related to the operations in the United States and Denmark, primarily representing cash payments for severance and other personnel-related expenses. Of the total restructuring charge, $2.5 million was recorded in cost of product sales, and $0.5 million was recorded in selling, general and administrative expenses. There was no restructuring reserve as of December 31, 2015 or 2016 as a result of cash payments made for severance and other personnel-related expenses.

R&D Restructuring

Given the expense required to conduct further development and the Company's focus on growing its existing commercial products and becoming profitable, at this time, the Company does not have current plans to initiate or fund a Phase 3 trial related to the ixCELL-DCM study on its own. As a result of no current need to manufacture ixmyelocel-T at the Ann Arbor facility, the Company recorded an asset retirement obligation of $0.2 million related to the suspension of operations in the Ann Arbor cleanroom facility and recorded a severance accrual of $0.1 million in research and development expenses related to this suspension as of December 31, 2016.