XML 95 R40.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Intangible Assets and Goodwill (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract] |
Intangible assets |
|  |  | As of December 31, 2016 |  | As of December 31, 2015
(In millions) | Estimated Life |  | Cost |  | Accumulated Amortization |  | Net |  | Cost |  | Accumulated Amortization |  | Net
Out-licensed patents | 13-23 years |  | $ | 543.3 |  |  | $ | (523.6 | ) |  | $ | 19.7 |  |  | $ | 543.3 |  |  | $ | (506.0 | ) |  | $ | 37.3 |
Developed technology | 15-23 years |  | 3,005.3 |  |  | (2,634.3 | ) |  | 371.0 |  |  | 3,005.3 |  |  | (2,552.9 | ) |  | 452.4 |
In-process research and development | Indefinite until commercialization |  | 648.0 |  |  | — |  |  | 648.0 |  |  | 730.5 |  |  | — |  |  | 730.5 |
Trademarks and trade names | Indefinite |  | 64.0 |  |  | — |  |  | 64.0 |  |  | 64.0 |  |  | — |  |  | 64.0 |
Acquired and in-licensed rights and patents | 6-18 years |  | 3,481.7 |  |  | (776.1 | ) |  | 2,705.6 |  |  | 3,303.2 |  |  | (502.3 | ) |  | 2,800.9 |
Total intangible assets |  |  | $ | 7,742.3 |  |  | $ | (3,934.0 | ) |  | $ | 3,808.3 |  |  | $ | 7,646.3 |  |  | $ | (3,561.2 | ) |  | $ | 4,085.1 |
Estimated future amortization of intangible assets |
(In millions) | As of December 31, 2016
2017 | $ | 334.8 |
2018 | 312.7 |
2019 | 295.2 |
2020 | 259.7 |
2021 | 242.8 |
Summary of roll forward of the changes in goodwill |
| As of December 31,
(In millions) | 2016 |  | 2015
Goodwill, beginning of year | $ | 2,663.8 |  |  | $ | 1,760.2 |
Increase to goodwill | 1,026.9 |  |  | 908.1 |
Other | (21.4 | ) |  | (4.5 | )
Goodwill, end of year | $ | 3,669.3 |  |  | $ | 2,663.8 |

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