XML 105 R41.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Intangible Assets and Goodwill (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract] |
Intangible assets | Intangible assets, net of accumulated amortization, impairment charges and adjustments are summarized as follows:
|  |  | As of December 31, 2017 |  | As of December 31, 2016
(In millions) | Estimated Life |  | Cost |  | Accumulated Amortization |  | Net |  | Cost |  | Accumulated Amortization |  | Net
Out-licensed patents | 13-23 years |  | $ | 543.3 |  |  | $ | (535.6 | ) |  | $ | 7.7 |  |  | $ | 543.3 |  |  | $ | (523.6 | ) |  | $ | 19.7 |
Developed technology | 15-23 years |  | 3,005.3 |  |  | (2,689.0 | ) |  | 316.3 |  |  | 3,005.3 |  |  | (2,634.3 | ) |  | 371.0 |
In-process research and development | Indefinite until commercialization |  | 680.6 |  |  | — |  |  | 680.6 |  |  | 648.0 |  |  | — |  |  | 648.0 |
Trademarks and trade names | Indefinite |  | 64.0 |  |  | — |  |  | 64.0 |  |  | 64.0 |  |  | — |  |  | 64.0 |
Acquired and in-licensed rights and patents | 4-18 years |  | 3,971.4 |  |  | (1,160.4 | ) |  | 2,811.0 |  |  | 3,481.7 |  |  | (776.1 | ) |  | 2,705.6 |
Total intangible assets |  |  | $ | 8,264.6 |  |  | $ | (4,385.0 | ) |  | $ | 3,879.6 |  |  | $ | 7,742.3 |  |  | $ | (3,934.0 | ) |  | $ | 3,808.3 |
Estimated future amortization of intangible assets | Based upon this analysis, the estimated future amortization of acquired intangible assets for the next five years is expected to be as follows:
(In millions) | As of December 31, 2017
2018 | $ | 423.5 |
2019 | 401.8 |
2020 | 381.6 |
2021 | 254.3 |
2022 | 242.3 |
Summary of roll forward of the changes in goodwill | The following table provides a roll forward of the changes in our goodwill balance:
| As of December 31,
(In millions) | 2017 |  | 2016
Goodwill, beginning of year | $ | 3,669.3 |  |  | $ | 2,663.8 |
Elimination of goodwill allocated to our hemophilia business | (314.1 | ) |  | — |
Increase to goodwill | 1,267.3 |  |  | 1,026.9 |
Other | 10.0 |  |  | (21.4 | )
Goodwill, end of year | $ | 4,632.5 |  |  | $ | 3,669.3 |

X
- Definition Intangible assets excluding goodwill. + References No definition available. + Details
Name: | biib_IntangibleAssetsExcludingGoodwillTableTextBlock
Namespace Prefix: | biib_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267 + Details
Name: | us-gaap_ScheduleOfGoodwillTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
Name: | us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration