7.  Intangible Assets

 

The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of December 31, 2016 are as follows (in thousands):

 

 

 

The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of December 31, 2015 are as follows (in thousands):

 

 

The change in the gross carrying amount of the acquired technology from December 31, 2015 to December 31, 2016 is due to changes attributed to foreign currency translation.

 

Amortization expense for acquired identifiable intangible assets for the years ended December 31, 2016, 2015, and 2014 was $0.6 million, $1.0 million, and $2.4 million, respectively. Estimated amortization expense for subsequent years is as follows (in thousands):