Reconstructive | MedSurg | Neurotechnology and Spine | Total | |||||||||||||
Balance as of January 1, 2012 | $ | 685 | $ | 510 | $ | 877 | $ | 2,072 | ||||||||
Goodwill acquired | 8 | — | 67 | 75 | ||||||||||||
Foreign currency translation effects and other | (2 | ) | 3 | (6 | ) | (5 | ) | |||||||||
Balance as of December 31, 2012 | 691 | 513 | 938 | 2,142 | ||||||||||||
Goodwill acquired | 1,559 | 2 | 108 | 1,669 | ||||||||||||
Transfers | (17 | ) | (9 | ) | 26 | — | ||||||||||
Foreign currency translation effects and other | (6 | ) | — | 39 | 33 | |||||||||||
Balance as of December 31, 2013 | $ | 2,227 | $ | 506 | $ | 1,111 | $ | 3,844 |
Gross Carrying Amount | Less Accumulated Amortization | Net Carrying Amount | |||||||||||||||||||
2013 | 2012 | 2013 | 2012 | 2013 | 2012 | ||||||||||||||||
Intangible assets: | |||||||||||||||||||||
Developed technologies | $ | 1,450 | 1,069 | $ | 380 | 282 | $ | 1,070 | 787 | ||||||||||||
Customer relationships | 677 | 563 | 189 | 147 | 488 | 416 | |||||||||||||||
Patents | 238 | 230 | 190 | 182 | 48 | 48 | |||||||||||||||
Trademarks | 127 | 69 | 34 | 31 | 93 | 38 | |||||||||||||||
In-process research and development | 223 | 86 | — | — | 223 | 86 | |||||||||||||||
Other | 118 | 105 | 51 | 56 | 67 | 49 | |||||||||||||||
$ | 2,833 | $ | 2,122 | $ | 844 | $ | 698 | $ | 1,989 | $ | 1,424 |
2014 | 2015 | 2016 | 2017 | 2018 | |||||||||||
Estimated amortization expense | $ | 167 | $ | 163 | $ | 162 | $ | 158 | $ | 156 |