Biogen (BIIB) 10-K 9 Feb 10 2009 FY Annual report Financial data

Document and Company Informatio

Document and Company Information (USD $)
	12 Months Ended Dec. 31, 2009	Feb. 05, 2010	Jun. 30, 2009
Document And Company Information [Abstract]
Entity Registrant Name	BIOGEN IDEC INC.
Entity Central Index Key	0000875045
Document Type	10-K
Document Period End Date	2009-12-31
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$13,005,469,098
Entity Common Stock, Shares Outstanding		269,601,262

Consolidated Statements of Inco

Consolidated Statements of Income (USD $)
In Thousands, except Per Share data	12 Months Ended Dec. 31, 2009	12 Months Ended Dec. 31, 2008	12 Months Ended Dec. 31, 2007
Revenues:
Product	$3,152,941	$2,839,651	$2,136,821
Unconsolidated joint business	1,094,863	1,128,238	926,098
Other	129,544	129,618	108,698
Total revenues	4,377,348	4,097,507	3,171,617
Costs and expenses:
Cost of sales, excluding amortization of acquired intangible assets	382,104	401,989	335,192
Research and development	1,283,068	1,072,058	925,164
Selling, general and administrative	911,034	925,305	776,103
Collaboration profit sharing	215,904	136,041	14,079
Amortization of acquired intangible assets	289,811	332,745	257,495
Acquired in-process research and development	0	25,000	84,172
Gain on dispositions, net	0	(9,242)	(360)
Total costs and expenses	3,081,921	2,883,896	2,391,845
Income from operations	1,295,427	1,213,611	779,772
Other income (expense), net	37,252	(57,728)	72,396
Income before income tax expense	1,332,679	1,155,883	852,168
Income tax expense	355,617	365,776	272,423
Net income	977,062	790,107	579,745
Net income (loss) attributable to noncontrolling interest, net of tax	6,930	6,940	(58,427)
Net income attributable to Biogen Idec Inc.	$970,132	$783,167	$638,172
Net income per share:
Basic earnings per share attributable to Biogen Idec Inc.	3.37	2.67	2.02
Diluted earnings per share attributable to Biogen Idec Inc.	3.35	2.65	1.99
Weighted-average shares used in calculating:
Basic earnings per share attributable to Biogen Idec Inc.	287,356	292,332	315,836
Diluted earnings per share attributable to Biogen Idec Inc.	289,476	294,984	320,171

Consolidated Balance Sheets

Consolidated Balance Sheets (USD $)
In Thousands	Dec. 31, 2009	Dec. 31, 2008
Current assets:
Cash and cash equivalents	$581,889	$622,385
Marketable securities	681,835	719,586
Collateral received for loaned securities	0	29,991
Accounts receivable, net of allowances of $43,818 and $32,047 at December 31, 2009 and 2008, respectively	551,208	446,665
Due from unconsolidated joint business	193,789	206,925
Loaned securities	0	29,446
Inventory	293,950	263,602
Other current assets	177,924	139,400
Total current assets	2,480,595	2,458,000
Marketable securities	1,194,080	891,406
Property, plant and equipment, net	1,637,083	1,594,754
Intangible assets, net	1,871,078	2,161,058
Goodwill	1,138,621	1,138,621
Investments and other assets	230,397	235,152
Total assets	8,551,854	8,478,991
Current liabilities:
Collateral payable on loaned securities	0	29,991
Accounts payable	118,534	107,417
Taxes payable	75,891	223,260
Accrued expenses and other	500,755	534,887
Current portion of notes payable and line of credit	19,762	27,667
Total current liabilities	714,942	923,222
Notes payable and line of credit	1,080,207	1,085,431
Long-term deferred tax liability	240,618	356,017
Other long-term liabilities	254,205	280,369
Total liabilities	2,289,972	2,645,039
Shareholders' Equity:
Preferred stock, par value $0.001 per share (8,000 shares authorized, of which 1,750 are designated Series A and 1,000 are designated Series X Junior Participating; 8 shares of Series A issued and outstanding with a $551 liquidation value at December 31, 2009 and 2008)	0	0
Common stock, par value $0.0005 per share (1,000,000 shares authorized; 288,494 shares issued and 274,855 shares outstanding at December 31, 2009; 297,253 shares issued and 288,046 shares outstanding at December 31, 2008)	144	149
Additional paid-in capital	5,781,920	6,073,957
Accumulated other comprehensive income (loss)	50,496	(11,106)
Retained earnings	1,068,890	270,180
Treasury stock, at cost; 13,639 and 9,207 shares at December 31, 2009 and 2008, respectively	(679,920)	(527,097)
Total Biogen Idec Inc. shareholders' equity	6,221,530	5,806,083
Noncontrolling interest	40,352	27,869
Total shareholders' equity	6,261,882	5,833,952
Total liabilities and shareholders' equity	$8,551,854	$8,478,991

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (USD $)
In Thousands, except Per Share data	Dec. 31, 2009	Dec. 31, 2008
Current assets:
Allowance for doubtful accounts receivable, current	$43,818	$32,047
Shareholders' Equity:
Preferred stock, par value	0.001	0.001
Preferred stock, shares authorized	8,000	8,000
Preferred stock, liquidation value per share of Series A	$551	$551
Common stock, par value	0.0005	0.0005
Common stock, shares authorized	1,000,000	1,000,000
Common stock, shares issued	288,494	297,253
Common stock, shares outstanding	274,855	288,046
Treasury stock, at cost	13,639	9,207
Series X Junior Participating Preferred Stock
Shareholders' Equity:
Preferred stock, shares authorized	1,000	1,000
Series A Preferred Stock
Shareholders' Equity:
Preferred stock, shares authorized	1,750	1,750
Preferred stock, shares issued	8	8
Preferred stock, shares outstanding	8	8

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (USD $)
In Thousands	12 Months Ended Dec. 31, 2009	12 Months Ended Dec. 31, 2008	12 Months Ended Dec. 31, 2007
Cash flows from operating activities:
Net income	$977,062	$790,107	$579,745
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization of property, plant and equipment and intangible assets	427,961	462,059	380,293
Acquired in process research and development and license	0	25,000	136,172
Share-based compensation	160,902	146,207	123,129
Cash received upon termination of interest rate swap	0	53,873	0
Non-cash interest (income) expense and foreign exchange remeasurement, net	(7,892)	(4,934)	1,444
Deferred income taxes	(137,351)	(139,549)	(81,555)
Realized (gain) loss on sale of marketable securities and strategic investments	(23,974)	1,078	(16,732)
Write-down of inventory to net realizable value	16,924	29,850	21,599
Gain on sale of property, plant and equipment, net	0	(9,242)	(360)
Impairment of marketable securities, investments and other assets	16,184	61,644	24,445
Excess tax benefit from stock options	(3,436)	(27,990)	(69,666)
Changes in operating assets and liabilities, net:
Accounts receivable	(100,442)	(57,565)	(70,701)
Due from unconsolidated joint business	13,136	(40,239)	2,022
Inventory	(42,772)	(54,204)	(83,192)
Other assets	22,271	3,711	238
Accrued expenses and other current liabilities	(48,942)	146,420	30,579
Other liabilities and taxes payable	(194,733)	176,219	41,294
Net cash flows provided by operating activities	1,074,898	1,562,445	1,018,754
Cash flows from investing activities:
Purchases of marketable securities	(3,548,119)	(3,163,824)	(2,945,244)
Proceeds from sales and maturities of marketable securities	3,319,007	2,941,060	3,154,290
Acquisitions, net of cash acquired	0	(25,000)	(95,789)
Purchases of property, plant and equipment	(165,646)	(275,954)	(284,106)
Proceeds from sale of property, plant and equipment	0	0	16,669
Purchase of other investments	(44,086)	(20,373)	(23,672)
Proceeds from the sale of strategic investments	13,822	0	99,489
Collateral received under securities lending	29,991	178,218	(208,209)
Net cash flows used in investing activities	(395,031)	(365,873)	(286,572)
Cash flows from financing activities:
Purchase of treasury stock	(751,170)	(738,938)	(2,991,184)
Proceeds from issuance of stock for share-based compensation arrangements	47,810	178,486	489,180
Change in cash overdraft	12,275	(498)	(5,399)
Excess tax benefit from stock options	3,436	27,990	69,666
Proceeds from borrowings	0	986,980	1,512,913
Repayments of borrowings	(10,867)	(1,512,474)	(12,042)
Repayments of long-term debt	0	0	(6,563)
Net capital contribution from noncontrolling interest	4,356	2,047	1,881
Obligation under securities lending	(29,991)	(178,218)	208,209
Net cash flows used in financing activities	(724,151)	(1,234,625)	(733,339)
Net decrease in cash and cash equivalents	(44,284)	(38,053)	(1,157)
Effect of exchange rate changes on cash and cash equivalents	3,788	776	(558)
Cash and cash equivalents, beginning of the year	622,385	659,662	661,377
Cash and cash equivalents, end of the year	581,889	622,385	659,662
Cash paid during the year for:
Interest	68,094	40,026	35,439
Income taxes	745,402	371,978	251,928
Non-cash financing activity:
Conversion of subordinated notes to common and treasury stock	$0	$0	$38,986

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity (USD $)
In Thousands	Biogen Idec Inc. Shareholders Equity	Common Stock	Preferred Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings/(accumulated deficit)	Accumulated other comprehensive income	Noncontrolling Interest	Total
Beginning Balance, shares at Dec. 31, 2006		345,637	8		(7,463)
Beginning Balance at Dec. 31, 2006	$7,149,778	$173		$8,308,232	($319,655)	($860,827)	$21,855	$9,839	$7,159,617
Comprehensive income:
Net income	638,172					638,172		(58,427)	579,745
Unrealized loss on securities available for sale, net of tax of ($379), ($1,123) and ($3,984) for year 2009, 2008 and 2007, respectively	9,124						9,124		9,124
Unrealized gains on foreign currency forward contracts, net of tax of ($3,582), $1,522 and $2,263 for year 2009, 2008 and 2007, respectively	(3,962)						(3,962)		(3,962)
Unrealized loss on pension benefit obligation, net of tax of ($67), $0 and ($370) for year 2009, 2008 and 2007, respectively	2,421						2,421		2,421
Translation adjustment	49,808						49,808	1,397	51,205
Total comprehensive income	695,563							(57,030)	638,533
Fair value of assets and liabilities acquired and assigned to noncontrolling interest due to the adoption of a new accounting standard for the consolidation of variable interests								65,038	65,038
Capital contribution from noncontrolling interest								1,881	1,881
Repurchase and retirement of common stock pursuant to tender offer	(2,991,184)	(29)		(2,991,155)					(2,991,184)
Repurchase and retirement of common stock pursuant to tender offer, shares		(56,424)
Issuance of treasury stock from conversion of subordinated notes payable	36,113				119,795	(83,682)			36,113
Issuance of treasury stock from conversion of subordinated notes payable, shares					2,850
Issuance of common stock from conversion of subordinated notes payable	2,371			2,371					2,371
Issuance of common stock from conversion of subordinated notes payable, shares		182
Issuance of treasury stock under stock option and stock purchase plans	101,896				135,720	(33,824)			101,896
Issuance of treasury stock under stock option and stock purchase plans, shares					2,994
Issuance of common stock under stock option and stock purchase plans	386,932	4		386,928					386,932
Issuance of common stock under stock option and stock purchase plans, shares		8,017
Issuance of treasury stock under stock award plans	(30,081)			(48,292)	18,076	135			(30,081)
Issuance of treasury stock under stock award plans, shares					465
Issuance of common stock under stock award plans	(3,420)			(2,744)		(676)			(3,420)
Issuance of common stock under stock award plans, shares		45
Forfeiture of common stock under restricted stock plan					(2,378)	2,378
Forfeiture of common stock under restricted stock plan, shares		(16)			(50)
Compensation expense related to share-based payments	128,101			128,101					128,101
Tax benefit from share-based payments	67,227			67,227					67,227
Adjustment for adoption for accounting of uncertain tax positions	(8,998)			(10,583)		1,585			(8,998)
Treasury stock reclassifications	(3)	(1)		(33,014)	48,442	(15,430)			(3)
Treasury stock reclassifications, shares		(1,743)			1,204
Ending Balance at Dec. 31, 2007	5,534,295	147		5,807,071		(352,169)	79,246	19,728	5,554,023
Ending Balance, shares at Dec. 31, 2007		295,698	8
Comprehensive income:
Net income	783,167					783,167		6,940	790,107
Unrealized loss on securities available for sale, net of tax of ($379), ($1,123) and ($3,984) for year 2009, 2008 and 2007, respectively	(67)						(67)		(67)
Unrealized gains on foreign currency forward contracts, net of tax of ($3,582), $1,522 and $2,263 for year 2009, 2008 and 2007, respectively	(36,140)						(36,140)		(36,140)
Unrealized loss on pension benefit obligation, net of tax of ($67), $0 and ($370) for year 2009, 2008 and 2007, respectively	(43)						(43)		(43)
Translation adjustment	(54,102)						(54,102)	(846)	(54,948)
Total comprehensive income	692,815							6,094	698,909
Distribution to noncontrolling interest								(2,817)	(2,817)
Capital contribution from noncontrolling interest								4,864	4,864
Repurchase of common stock for Treasury, at cost	(738,938)				(738,938)				(738,938)
Repurchase of common stock for Treasury, shares					(12,778)
Issuance of common stock from conversion of subordinated notes payable	227			227					227
Issuance of common stock from conversion of subordinated notes payable, shares		16
Issuance of common stock under stock option and stock purchase plans	178,486	1		34,297	200,411	(56,223)			178,486
Issuance of common stock under stock option and stock purchase plans, shares		852			3,380
Issuance of common stock under stock award plans	(44,395)	1		(29,800)	11,430	(26,026)			(44,395)
Issuance of common stock under stock award plans, shares		688			191
Forfeiture of common stock under restricted stock plan, shares		(1)
Compensation expense related to share-based payments	153,748			153,748					153,748
Tax benefit from share-based payments	29,845			29,845					29,845
Treasury stock reclassifications				78,569		(78,569)
Ending Balance at Dec. 31, 2008	5,806,083	149		6,073,957	(527,097)	270,180	(11,106)	27,869	5,833,952
Ending Balance, shares at Dec. 31, 2008		297,253	8		(9,207)
Comprehensive income:
Net income	970,132					970,132		6,930	977,062
Unrealized loss on securities available for sale, net of tax of ($379), ($1,123) and ($3,984) for year 2009, 2008 and 2007, respectively	795						795		795
Unrealized gains on foreign currency forward contracts, net of tax of ($3,582), $1,522 and $2,263 for year 2009, 2008 and 2007, respectively	41,668						41,668		41,668
Unrealized loss on pension benefit obligation, net of tax of ($67), $0 and ($370) for year 2009, 2008 and 2007, respectively	501						501		501
Translation adjustment	18,638						18,638	1,197	19,835
Total comprehensive income	1,031,734							8,127	1,039,861
Distribution to noncontrolling interest								(2,832)	(2,832)
Capital contribution from noncontrolling interest								7,188	7,188
Repurchase of common stock for Treasury, at cost	(751,170)				(751,170)				(751,170)
Repurchase of common stock for Treasury, shares					(15,982)
Retirement of common stock pursuant to 2009 stock repurchase plan	0	(5)		(422,415)	422,420				0
Retirement of common stock pursuant to 2009 stock repurchase plan, shares		(8,759)			8,759
Issuance of treasury stock under stock option and stock purchase plans	47,810				75,001	(27,191)			47,810
Issuance of treasury stock under stock option and stock purchase plans, shares					1,181
Issuance of treasury stock under stock award plans	(43,305)				100,926	(144,231)			(43,305)
Issuance of treasury stock under stock award plans, shares					1,610
Compensation expense related to share-based payments	167,207			167,207					167,207
Tax benefit from share-based payments	(36,829)			(36,829)					(36,829)
Ending Balance at Dec. 31, 2009	$6,221,530	$144		$5,781,920	($679,920)	$1,068,890	$50,496	$40,352	$6,261,882
Ending Balance, shares at Dec. 31, 2009		288,494	8		(13,639)

1_Consolidated Statements of Sh

Consolidated Statements of Shareholders Equity (Parenthetical) (USD $)
In Thousands	Biogen Idec Inc. Shareholders Equity	Accumulated other comprehensive income	Total
Comprehensive income:
Tax effect on unrealized gains on securities available for sale	($3,984)	($3,984)	($3,984)
Tax effect on unrealized loss on foreign currency forward contracts	2,263	2,263	2,263
Tax effect on unrealized gains on pension benefit obligation	(370)	(370)	(370)
Comprehensive income:
Tax effect on unrealized gains on securities available for sale	(1,123)	(1,123)	(1,123)
Tax effect on unrealized loss on foreign currency forward contracts	1,522	1,522	1,522
Tax effect on unrealized gains on pension benefit obligation	0	0	0
Comprehensive income:
Tax effect on unrealized gains on securities available for sale	(379)	(379)	(379)
Tax effect on unrealized loss on foreign currency forward contracts	(3,582)	(3,582)	(3,582)
Tax effect on unrealized gains on pension benefit obligation	($67)	($67)	($67)

Summary of Significant Accounti

Summary of Significant Accounting Policies
	12 Months Ended Dec. 31, 2009 USD / shares
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies Basis of Presentation Consolidation Biogen Idec Inc. (Biogen Idec, we, us or the Company) is a global biotechnology company that creates new standards of care in therapeutic areas with high unmet medical needs. Our consolidated financial statements reflect our financial statements, those of our wholly-owned subsidiaries, certain variable interest entities in which we are the primary beneficiary and those of our joint ventures in Italy and Switzerland, Biogen Domp SRL and Biogen Domp Switzerland GmbH, respectively. For such consolidated entities in which we own less than a 100% interest, we record net income (loss) attributable to noncontrolling interest in our consolidated statements of income equal to the percentage of the interest retained in the collaborative arrangement by the respective noncontrolling parties. All material intercompany balances and transactions have been eliminated in consolidation. In determining whether we are the primary beneficiary, we consider a number of factors, including determining the expected losses and residual returns of the technologies being developed pursuant to collaborations and other economic risk and reward of such collaborations; these considerations impact the way we account for our existing collaborative relationships and may result in the future consolidation of companies or entities with which we have a collaborative arrangement. Use of Estimates The preparation of consolidated financial statements in accordance with U.S.GAAP requires our management to make estimates and judgments that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an ongoing basis, we evaluate our estimates and judgments, including those related to revenue recognition and related allowances, marketable securities, derivatives and hedging activities, inventory, impairments of long-lived assets including intangible assets, impairments of goodwill, income taxes including the valuation allowance for deferred tax assets, valuation of investments, research and development expenses, contingencies and litigation, and share-based payments. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different assumptions or conditions. Reclassifications Where specified, certain prior-year amounts have been reclassified to conform to the current years presentation. Subsequent Events We evaluated all events and transactions through February9, 2009, the date we issued these financial statements. During this period we did not have any material recognizable subsequent events. However, we did have the following nonrecognizable subsequent events: In January 2010, Syntonix Pharmaceuticals, Inc. (Syntonix) achieved a significant development milestone obligating us to pay $40.0million to its former shareholders. As th

Acquisitions and Dispositions

Acquisitions and Dispositions
	12 Months Ended Dec. 31, 2009 USD / shares
Acquisitions and Dispositions [Abstract]
Acquisitions and Dispositions	2. Acquisitions and Dispositions Syntonix Pharmaceuticals, Inc. In January 2007, we acquired 100% of the stock of Syntonix. Syntonix focuses on discovering and developing long-acting therapeutic products to improve treatment regimens for chronic diseases, and is engaged in multiple programs in hemophilia. The purchase price was $44.4million, including transaction costs, and could increase to as much as $124.4million if certain development milestones with respect to Syntonixs lead product, long-acting recombinant Factor IX, a proprietary long-acting Factor IX product for the treatment of hemophilia B, are achieved. Under the acquisition agreement we also agreed to make additional future consideration payments upon the achievement of certain milestone events. Future contingent consideration payments, if any, will be recorded as IPRD. Due to the uncertainty surrounding triggering events related to the attainment of milestones, such charges and related obligations are generally recorded when the milestone has been achieved. The acquisition was funded from our existing cash on hand and was accounted for as an asset acquisition as Syntonix was a development-stage company. The purpose of the acquisition was to enhance our pipeline and to expand into additional specialized markets and as a result of the acquisition we obtained the rights to the in-process technology of the Fc-fusion technology platform. Syntonix has two programs in development using the Fc-fusion platform, long-acting recombinant Factor IX and long-acting recombinant Factor VIII. Syntonixs lead product, long-acting recombinant Factor IX, is a proprietary long-acting Factor IX product for the treatment of hemophilia B. Long-acting recombinant Factor VIII is a product being developed for the treatment of hemophilia A and is the subject of a Phase 1 study in hemophilia A. In January 2010, we initiated patient enrollment in a registrational study for long-acting recombinant Factor IX in hemophilia B. The initiation of this study resulted in the achievement of a significant milestone, obligating us to pay $40.0million to the former shareholders of Syntonix. As the milestone occurred subsequent to December31, 2009, the obligation is not reflected in our consolidated balance sheet as of that date and will be reflected as IPRD expense in the first quarter of 2010. The results of operations of Syntonix are included in our consolidated results of operations from the date of acquisition. We have completed our purchase price allocation for the acquisition as set out below: (In millions) Total Current assets $ 0.3 Fixed assets 0.2 Deferred tax asset 27.8 Assembled workforce 0.7 In-process research and development 18.4 Current liabilities (3.0 ) Total purchase price $ 44.4 The purchase price included $2.0million in loan forgiveness and $0.7million in transaction fees. In addition, $0.3million of severance charges were accrued as a result of the acquisition. The amount allocated to IPRD relates to the developm

Reserves

Reserves
	12 Months Ended Dec. 31, 2009 USD / shares
Reserves [Abstract]
Reserves	3. Reserves Reserves for Discounts and Allowances Revenues are recorded net of applicable reserves for trade term discounts, wholesaler incentives, Medicaid rebates, VA rebates, managed care rebates, product returns and other applicable allowances. Reserves established for these discounts and allowances are classified as reductions of accounts receivable (if the amount is payable to our customer) or a liability (if the amount is payable to a party other than our customer). Our product revenue reserves are based on estimates of the amounts earned or to be claimed on the related sales. These estimates take into consideration our historical experience, current contractual requirements and statutory requirements, specific known market events and trends and forecasted customer buying patterns. If actual future results vary, we may need to adjust these estimates, which could have an effect on earnings in the period of the adjustment. An analysis of the amount of, and change in, reserves is summarized as follows: Contractual (In millions) Discounts Adjustments Returns Total 2009 Beginning balance $ 9.2 $ 48.1 $ 18.1 $ 75.4 Current provisions relating to sales in current year 74.0 192.5 15.8 282.3 Adjustments relating to prior years 0.8 0.8 Payments/returns relating to sales in current year (60.8 ) (124.4 ) (0.6 ) (185.8 ) Payments/returns relating to sales in prior years (8.5 ) (45.9 ) (15.2 ) (69.6 ) Ending balance $ 13.9 $ 70.3 $ 18.9 $ 103.1 2008 Beginning balance $ 6.4 $ 33.1 $ 20.4 $ 59.9 Current provisions relating to sales in current year 67.1 150.6 14.7 232.4 Adjustments relating to prior years (1.6 ) (2.5 ) (4.1 ) Payments/returns relating to sales in current year (57.8 ) (101.2 ) (0.1 ) (159.1 ) Payments/returns relating to sales in prior years (6.5 ) (32.8 ) (14.4 ) (53.7 ) Ending balance $ 9.2 $ 48.1 $ 18.1 $ 75.4 2007 Beginning balance $ 12.7 $ 30.5 $ 17.8 $ 61.0 Current provisions relating to sales in current year 45.7 113.1 17.1 175.9 Adjustments relating to prior years (7.9 ) 5.0 (2.9 ) Payments/returns relating to sa

Inventory

Inventory
	12 Months Ended Dec. 31, 2009 USD / shares
Inventory [Abstract]
Inventory	4. Inventory The components of inventories are summarized as follows: As of December31, (In millions) 2009 2008 Raw materials $ 49.2 $ 29.8 Work in process 174.0 180.0 Finished goods 70.8 53.8 Total inventory $ 294.0 $ 263.6 The following table provides a summary of work in process and finished goods by product: As of December31, (In millions) 2009 2008 AVONEX $ 76.8 $ 79.2 TYSABRI 144.0 126.2 Other 24.0 28.4 Total finished goods and work in process $ 244.8 $ 233.8 Raw materials 49.2 29.8 Total inventory $ 294.0 $ 263.6 Write-downs from Unmarketable Inventory Amounts written-down related to unmarketable inventory are charged to cost of sales, excluding amortization of acquired intangible assets. Amounts written-down during 2009, 2008, and 2007 totaled $16.9million, $29.8million and $21.6million, respectively.

Intangible Assets and Goodwill

Intangible Assets and Goodwill
	12 Months Ended Dec. 31, 2009 USD / shares
Intangible Assets and Goodwill [Abstract]
Intangible Assets and Goodwill	5. Intangible Assets and Goodwill Intangible assets, net of accumulated amortization, impairment charges and adjustments, are summarized as follows: As of December31, 2009 As of December31, 2008 Estimated Accumulated Accumulated (In millions) Life Cost Amortization Net Cost Amortization Net Out-licensed patents 12years $ 578.0 $ (306.0 ) $ 272.0 $ 578.0 $ (250.3 ) $ 327.7 Core developed technology 15-23years 3,005.3 (1,472.4 ) 1,532.9 3,005.3 (1,241.0 ) 1,764.3 Trademarks and tradenames Indefinite 64.0 64.0 64.0 64.0 In-licensed patents 14years 3.0 (1.1 ) 1.9 3.0 (0.9 ) 2.1 Assembled workforce 4years 2.1 (1.8 ) 0.3 2.1 (1.2 ) 0.9 Distribution rights 2years 12.7 (12.7 ) 12.7 (10.6 ) 2.1 Total intangible assets $ 3,665.1 $ (1,794.0 ) $ 1,871.1 $ 3,665.1 $ (1,504.0 ) $ 2,161.1 Intangible Assets Intangible assets were unchanged as of December31, 2009 as compared to December31, 2008 exclusive of the impact of foreign exchange and amortization. In September 2009, we were issued a U.S.patent for the use of beta interferon for immunomodulation or treating a viral condition, viral disease, cancers or tumors. This patent, expiring in September 2026, covers the treatment of multiple sclerosis with AVONEX, which is our brand of recombinant beta interferon and extends the expected remaining life of the related core intangible asset. Amortization of Acquired Intangible Assets For the Years Ended December31, (In millions) 2009 2008 2007 Amortization of acquired intangible assets $ 289.8 $ 332.7 $ 257.5 Our most significant intangible asset is the core technology related to our AVONEX product. We believe the economic benefit of our core technology is consumed as revenue is generated from our AVONEX product, which we refer to as the economic consumption amortization model. An analysis of the anticipated product sales of AVONEX is performed annually during our long range planning cycle each year. This analysis serves as the basis for the calculation of economic consumption for the core technology intangible asset. We completed our most recent long range planning cycle in the third quarter of 2009, which includes an analysis of the anticipated product sales of AVONEX. Based upon our most recent analysis, amortization of intangible assets included within our co

Fair Value Measurements

Fair Value Measurements
	12 Months Ended Dec. 31, 2009 USD / shares
Fair Value Measurements [Abstract]
Fair Value Measurements	6. Fair Value Measurements Summary of Assets and Liabilities Recorded at Fair Value The tables below present information about our assets and liabilities that are measured at fair value on a recurring basis as of December31, 2009 and 2008 and indicate the fair value hierarchy of the valuation techniques we utilized to determine such fair value, which is described further within Note1, Summary of Significant Accounting Policies to our Consolidated Financial Statements. A majority of our financial assets and liabilities have been classified as Level2. These assets and liabilities have been initially valued at the transaction price and subsequently valued typically utilizing third party pricing services. The pricing services use many observable market inputs to determine value, including reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events. We validate the prices provided by our third party pricing services by understanding the models used, obtaining market values from other pricing sources, analyzing pricing data in certain instances and confirming those securities trade in active markets. After completing our validation procedures, we did not adjust or override any fair value measurements provided by our pricing services as of December31, 2009 and 2008. Our strategic investments in publicly traded equity securities are classified as Level1 assets as their fair values are readily determinable and based on quoted market prices. Our venture capital investments are the only assets for which we used Level3 inputs to determine the fair value. Venture capital investments represented approximately 0.3% of total assets as of December31, 2009 and 2008. We have funding commitments of up to approximately $24.8million as part of our investment in these funds. These funds primarily invest in small privately-owned, ventured-backed, biotechnology companies. The fair value of funds has been estimated using the net asset value of our ownership interest in partners capital. The investments cannot be redeemed within the funds. Distributions from each will be received as the underlying investments of the fund are liquidated. The funds and therefore a majority of the underlying assets of the funds will not be liquidated in the near future. The underlying assets in these funds are initially measured at transaction prices and subsequently valued using the pricing of recent financing or by reviewing the underlying economic fundamentals and liquidation value of the companies. Gains and losses (realized and unrealized) included in earnings for the period are reported in other income (expense), net. The following tables set forth our financial assets and liabilities that were recorded at fair value: Quoted Significant Prices Other Significant As of in Active Observable Unobservable December31, Markets Inputs Inputs (In millions) 2009 (Level 1)

Financial Instruments

Financial Instruments
	12 Months Ended Dec. 31, 2009 USD / shares
Financial Instruments [Abstract]
Financial Instruments	7. Financial Instruments Marketable Securities, including Strategic Investments The following tables summarize our marketable securities and strategic investments: Gross Gross Fair Unrealized Unrealized Amortized As of December31, 2009 (In millions): Value Gains Losses Cost Available-for-Sale Corporate debt securities Current $ 177.2 $ 1.5 $ $ 175.7 Non-current 326.9 5.7 (0.3 ) 321.5 Government securities Current 501.6 1.2 500.4 Non-current 631.9 4.1 (0.5 ) 628.3 Mortgage and other asset backed securities Current 3.0 0.1 2.9 Non-current 235.3 4.1 (0.5 ) 231.7 Total available-for-sale securities $ 1,875.9 $ 16.7 $ (1.3 ) $ 1,860.5 Other Investments Strategic investments, non-current $ 5.9 $ 2.7 $ (0.3 ) $ 3.5 Gross Gross Fair Unrealized Unrealized Amortized As of December31, 2008 (In millions): Value Gains Losses Cost Available-for-Sale Corporate debt securities Current $ 128.2 $ 0.4 $ $ 127.8 Non-current 200.3 2.6 197.7 Government securities Current 582.8 1.5 581.3 Non-current 422.2 8.7 413.5 Mortgage and other asset backed securities Current 13.9 13.9 Non-current 293.0 3.3 (0.3 ) 290.0 Total available-for-sale securities $ 1,640.4 $ 16.5 $ (0.3 ) $ 1,624.2 Other Investments Strategic investments, non-current $ 4.6 $ 0.5 $ (0.1 ) $ 4.2 In the tables above, as of December31, 2009 and 2008, government securities included $298.8million and $139.1million, respectively, of Federal Deposit Insurance Corporation (FDIC) guaranteed senior notes issued by financial institutions under the Temporary Liquidity

Derivative Instruments

Derivative Instruments
	12 Months Ended Dec. 31, 2009 USD / shares
Derivative Instruments [Abstract]
Derivative Instruments	8. Derivative Instruments Forward Contracts and Interest Rate Swaps On January1, 2009, we adopted a newly issued accounting standard which requires additional disclosure about our objectives for using derivative instruments, the level of derivative activity we engage in, and the effect of derivative instruments and related hedged items on our financial position and performance. The adoption of this standard did not impact our financial position or results of operations. Our primary market exposure is to foreign exchange rates and interest rates. We use certain derivative instruments to help manage these exposures. We execute these instruments with financial institutions we judge to be creditworthy and the majority of these instruments are denominated in currencies of major industrial countries. We do not hold or issue derivative instruments for trading or speculative purposes. We recognize all derivative instruments as either assets or liabilities at fair value in our consolidated balance sheets. We classify the cash flows from these instruments in the same category as the cash flows from the hedged items. Forward Contracts Due to the global nature of our operations, portions of our revenues are in currencies other than the U.S.dollar. The value of revenue measured in U.S.dollars is subject to changes in foreign exchange rates. In order to mitigate these changes we use forward contracts to lock in foreign exchange rates. We do not engage in currency speculation. All foreign currency forward contracts in effect as of December31, 2009 and 2008 had durations of 1 to 12months. These contracts have been designated as cash flow hedges and accordingly, to the extent effective, any unrealized gains or losses on these foreign currency forward contracts are reported in accumulated other comprehensive income (loss). Realized gains and losses for the effective portion of such contracts are recognized in revenue when the sale of product in the currency being hedged is recognized. To the extent ineffective, hedge transaction gains and losses are reported in other income (expense), net at each reporting date. Foreign currency forward contracts that were entered into to hedge forecasted revenue are summarized as follows: Notional Amount As of December31, Foreign Currency: (In millions) 2009 2008 Euro $ 495.9 $ 489.4 Canadian Dollar 22.3 34.1 Total $ 518.2 $ 523.5 The portion of the fair value of these contracts that was included in accumulated other comprehensive income (loss) within total equity reflected gains of $1.2million and losses of $44.1million as of December31, 2009 and 2008, respectively. We consider the impact of our and our counterparties credit risk on the fair value of the contracts as well as the ability of each party to execute its obligations under the contract. As of December31, 2009 and 2008, respectively, credit risk did not materially change the fair value of our foreign currency forward contracts. In re

Indebteness

Indebteness
	12 Months Ended Dec. 31, 2009 USD / shares
Indebtedness [Abstract]
Indebtedness	9. Indebtedness Our indebtedness is summarized as follows: As of December31, (In millions) 2009 2008 Current portion: Notes payable to Fumedica $ 11.2 $ 10.9 Credit line from Domp 8.6 16.8 Current portion of notes payable and line of credit $ 19.8 $ 27.7 Non-current portion: 6.0%Senior notes due 2013 $ 449.6 $ 449.6 6.875%Senior notes due 2018 603.2 608.2 Notes payable to Fumedica 18.8 27.6 Credit line from Domp 8.6 Notes payable and line of credit $ 1,080.2 $ 1,085.4 The following is a summary description of our principal indebtedness as of December31, 2009. Senior Notes On March4, 2008, we issued $450.0million aggregate principal amount of 6.0%Senior Notes due March1, 2013 and $550.0million aggregate principal amount of 6.875%Senior Notes due March1, 2018 at 99.886% and 99.184% of par, respectively. The discount is amortized as additional interest expense over the period from issuance through maturity. These notes are senior unsecured obligations. Interest on the notes is payable March 1 and September 1 of each year. The notes may be redeemed at our option at any time at 100% of the principal amount plus accrued interest and a specified make-whole amount. The notes contain a change of control provision that may require us to purchase the notes under certain circumstances. There is also an interest rate adjustment feature that requires us to pay interest at an increased interest rate on the notes if the credit rating on the notes declines below investment grade. Offering costs of approximately $8.0million have been recorded as debt issuance costs on our consolidated balance sheet and are amortized as additional interest expense using the effective interest rate method over the period from issuance through maturity. Upon the issuance of the debt we entered into interest rate swap contracts where we received a fixed rate and paid a variable rate, as further described in Note8, Derivative Instruments to our Consolidated Financial Statements. These contracts have been subsequently terminated. Upon termination of these swaps, the carrying amount of the 6.875%Senior Notes due in 2018 was increased by $62.8million. This increase is amortized using the effective interest rate method over the remaining life of the Senior Notes and is being recognized as a reduction of interest expense. We used the proceeds of this borrowing, along with cash and the proceeds from the liquidation of marketable securities, to repay the full $1,500.0million outstanding under the term loan facility we had entered into in July 2007 in connection with the funding of our June 2007 common stock tender offer. This term loan facility expired upon repayment. Revolving Credit Facility We have a $360.0million senior unsecured revolving credit facility, which may b

Shareholders' Equity

Shareholders' Equity
	12 Months Ended Dec. 31, 2009 USD / shares
Sahreholders' Equity [Abstract]
Shareholders' Equity	10. Shareholders Equity Preferred Stock Preferred stock was comprised of the following: As of December31, 2009 As of December31, 2008 As of December31, 2007 (In thousands) Authorized Issued Outstanding Authorized Issued Outstanding Authorized Issued Outstanding SeriesA Preferred Stock 1,750 8 8 1,750 8 8 1,750 8 8 SeriesX Junior Participating Preferred Stock 1,000 1,000 1,000 Undesignated 5,250 5,250 5,250 8,000 8 8 8,000 8 8 8,000 8 8 We have 8,000,000shares of Preferred Stock authorized, of which 1,750,000shares have been designated as SeriesA Preferred Stock and 1,000,000shares have been designated as SeriesX Junior Participating Preferred Stock. The balance may be issued without a vote or action of stockholders from time to time in classes or series with the designations, powers, preferences, and the relative, participating, optional or other special rights of the shares of each such class or series and any qualifications, limitations or restrictions thereon as set forth in the stock certificate. Any such Preferred Stock may rank prior to common stock as to dividend rights, liquidation preference or both, and may have full or limited voting rights and may be convertible into shares of common stock. As of December31, 2009, 2008 and 2007, there were 8,221shares of SeriesA Preferred Stock issued and outstanding. These shares carry a liquidation preference of $67 and are convertible into 60shares of common stock per share of Preferred Stock. No other shares of Preferred Stock are issued and outstanding as of December31, 2009, 2008 and 2007. Stockholder Rights Plan In January 2009, our Board of Directors voted to terminate our stockholders rights plan effective as of January30, 2009. The plan was scheduled to expire on July26, 2011 and was originally adopted by the Board of Directors in 1997. Under the rights plan, each share of our common stock had one right attached to it that entitled the holder to purchase our SeriesX Junior Participating Preferred Stock under the circumstances specified in the rights plan. As a result of our Board of Directors action, no rights are outstanding or exercisable. Stock Repurchase Programs In October 2009, our Board of Directors authorized the repurchase of up to $1.0billion of our common stock with repurchased shares being retired. This repurchase program does not have an expiration date. As of December31, 2009, approximately 8.8million shares at a cost of $422.4million were repur

Earnings per Share

Earnings per Share
	12 Months Ended Dec. 31, 2009 USD / shares
Earnings per Share [Abstract]
Earnings per Share	11. Earnings per Share Basic and diluted earnings per share are calculated as follows: For the Years Ended December31, (In millions) 2009 2008 2007 Numerator: Net income attributable to Biogen Idec Inc. $ 970.1 $ 783.2 $ 638.2 Adjustment for net income allocable to preferred shares (1.7 ) (1.3 ) (1.0 ) Net income used in calculating basic and diluted earnings per share $ 968.4 $ 781.9 $ 637.2 Denominator: Weighted average number of common shares outstanding 287.4 292.3 315.8 Effect of dilutive securities: Stock options and employee stock purchase plan 0.6 1.3 2.6 Restricted stock awards 0.1 0.5 Time-vested restricted stock units 1.4 1.3 1.1 Performance-vested restricted stock units 0.1 Convertible promissory notes due 2019 0.2 Convertible promissory notes due 2032 Dilutive potential common shares 2.1 2.7 4.4 Shares used in calculating diluted earnings per share 289.5 295.0 320.2 The following amounts were not included in the calculation of net income per basic and diluted share because their effects were anti-dilutive: For the Years Ended December31, (In millions) 2009 2008 2007 Numerator: Net income allocable to preferred stock $ 1.7 $ 1.3 $ 1.0 Denominator: Stock options 8.5 6.9 8.2 Time-vested restricted stock units 2.1 1.5 0.1 Performance-vested restricted stock units 0.2 Convertible preferred stock 0.5 0.5 0.5 Total 11.3 8.9 8.8 Earnings per share for the year ended December31, 2009 reflects, on a weighted average basis, the repurchase of 16.0millionshares of our common stock under our 2009 and 2006share repurchase programs. As a result of our 2007 tender offer, earnings per share for the year ended December31, 2007 reflects, on a weighted average basis, the repurchase of 56.4millionshares as of June27, 2007, the date the obligation was incurred, in accordance with accounting standards for earning per share.

Share-based Payments

Share-based Payments
	12 Months Ended Dec. 31, 2009 USD / shares
Share-based Payments [Abstract]
Share-based Payments	12. Share-based Payments Share-based Compensation Expense The following table summarizes share-based compensation expense included within our consolidated statements of income: For the Years Ended December31, (In millions) 2009 2008 2007 Research and development $ 60.8 $ 59.9 $ 51.7 Selling, general and administrative 106.4 93.8 76.1 Subtotal $ 167.2 $ 153.7 $ 127.8 Capitalized share-based compensation costs (6.3 ) (7.5 ) (4.7 ) Share-based compensation expense included in total costs and expenses $ 160.9 $ 146.2 $ 123.1 Income tax effect (49.4 ) (45.4 ) (37.5 ) Share-based compensation expense included in net income attributable to Biogen Idec Inc. $ 111.5 $ 100.8 $ 85.6 Our share-based compensation programs include stock options, time-vested restricted stock units, performance-vested restricted stock units, restricted stock and shares issued under our ESPP. The following table summarizes share-based compensation expense associated with each of these programs: For the Years Ended December31, (In millions) 2009 2008 2007 Stock options $ 21.6 $ 20.0 $ 30.7 Time-vested restricted stock units 133.7 125.6 75.2 Performance-vested restricted stock units 4.6 1.1 5.0 Restricted stock awards 0.5 11.7 Employee stock purchase plan 7.3 6.5 5.2 Subtotal $ 167.2 $ 153.7 $ 127.8 Capitalized share-based compensation costs (6.3 ) (7.5 ) (4.7 ) Share-based compensation expense included in total costs and expenses $ 160.9 $ 146.2 $ 123.1 Windfall tax benefits from vesting of stock awards, exercises of stock options and ESPP participation were $3.4million, $28.0million, and $69.7million in 2009, 2008, and 2007, respectively. These amounts have been calculated under the alternative transition method in accordance with U.S.GAAP. As of December31, 2009, unrecognized compensation cost related to unvested share-based compensation was approximately $178.1million, net of estimated forfeitures. We expect to recognize the cost of these unvested awards over a weighted-average period of 1.4years. Share-based Compensation Plans We have three share-based compensation plans pursuant to which awards are currently being made: (1)the Biogen Idec Inc. 2006 Non-Employee Directors Equity Plan (2006Directors Plan); (2)the Biogen Idec Inc. 2008 Omnibus Equity Plan (2008 Omnibus P

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)
	12 Months Ended Dec. 31, 2009 USD / shares
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss)	13. Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income (loss) consisted of the following: As of December31, (In millions) 2009 2008 Translation adjustments $ 35.6 $ 17.0 Unrealized gains on securites available for sale 11.3 10.5 Unrealized gains (losses) on foreign currency forward contracts 1.5 (40.2 ) Unfunded status of pension and postretirement benefit plans 2.1 1.6 Accumulated other comprehensive income (loss) $ 50.5 $ (11.1 ) Unrealized holding gains on securities available for sale is shown net of tax of $(6.6)million and $(6.2)million as of December31, 2009 and 2008, respectively. Unrealized gains (losses) on foreign currency forward contracts is shown net of tax of $0.3million, and $3.9million as of December31, 2009 and 2008, respectively. The unfunded status of pension and retirement benefit plans is shown net of tax as of December31, 2009 and 2008. Tax amounts in both years were immaterial. See Note15, Employee Benefit Plans to our Consolidated Financial Statements for discussion of unfunded status of pension and retirement benefit plans. Amounts comprising noncontrolling interests, as reported in our consolidated statements of equity as of December31, 2009 and 2008 included accumulated translation adjustments of $2.4million and $1.2million, respectively. Comprehensive income (loss) and its components are presented in the consolidated statements of shareholders equity.

Other Consolidated Financial St

Other Consolidated Financial Statement Detail
	12 Months Ended Dec. 31, 2009 USD / shares
Other Consolidated Financial Statement Detail [Abstract]
Other Consolidated Financial Statement Detail	14. Other Consolidated Financial Statement Detail Other Income (Expense), Net Components of other income (expense), net, are summarized as follows: For the Years Ended December31, (In millions) 2009 2008 2007 Interest income $ 48.5 $ 72.1 $ 103.6 Interest expense (35.8 ) (52.0 ) (40.5 ) Impairment on investments (10.6 ) (60.3 ) (24.4 ) Gain (loss) on sales of investments, net 22.8 (1.1 ) 16.7 Foreign exchange gains (losses), net 11.4 (9.8 ) 3.0 Gain on the sale of property 7.1 Other, net 1.0 (6.6 ) 6.9 Other income (expense), net $ 37.3 $ (57.7 ) $ 72.4 Interest Expense In 2009, we incurred interest costs of $69.7million. This amount was reduced by $28.5million because we capitalized interest related to the construction of our large scale manufacturing facility in Hillerd, Denmark. In addition, in 2009, approximately $5.4million was recorded as a reduction due to the amortization of the deferred gain associated with the termination of an interest rate swap in December 2008. In 2008, we incurred interest costs of $66.3million. This amount was reduced by $23.2million of capitalized interest on the manufacturing facility in Hillerd, Denmark. In addition, we incurred approximately $8.9million of expenses related to hedge ineffectiveness on interest rate swaps executed in March 2008. In 2007, we incurred interest costs of $50.6million, which were reduced by $10.1million of capitalized interest on the manufacturing facility in Hillerd, Denmark. Impairment on Investments In April 2009, we implemented newly issued accounting standards which provided guidance for recognition and presentation of other-than-temporary impairments. The adoption of the guidance did not have a material impact on our financial position or results of operations; however, this standard amended the other-than-temporary impairment model for marketable debt securities. The impairment model for equity securities was not affected. Refer to Note7, Financial Instruments to our Consolidated Financial Statements for additional information on the adoption of this guidance. In 2009, we recognized impairment losses of $7.0million on our strategic investments and non-marketable securities. In addition, during 2008 and 2007, we recognized $18.6million and $18.4million, respectively, in charges for the impairment of strategic investments and non-marketable securities that were determined to be other-than-temporary. In 2009, we recognized $3.6million in charges for the other-than-temporary impairment on marketable debt securities. For 2008 and 2007, we recognized $41.7million and $7.5million, respectively, in charges for the other-than-temporary impairment of marketable debt securities primarily related to mortgage and asset-bac

Employee Benefit Plans

Employee Benefit Plans
	12 Months Ended Dec. 31, 2009 USD / shares
Employee Benefit Plans [Abstract]
Employee Benefit Plans	15. Employee Benefit Plans 401(k) Savings Plan We maintain a 401(k) Savings Plan which is available to substantially all regular employees in the U.S.over the age of 21. Participants may make voluntary contributions. We make matching contributions according to the 401(k) Savings Plans matching formula. Beginning in January 2008, all past and current matching contributions will vest immediately. Previously, the matching contributions vested over four years of service by the employee. Participant contributions vest immediately. The 401(k) Savings Plan also holds certain transition contributions on behalf of participants who previously participated in the Biogen, Inc. Retirement Plan. The expense related to our 401(k) Savings Plan primarily consists of our matching contributions. For the Years Ended December31, (In millions) 2009 2008 2007 Expense related to our 401(k) Savings Plan $ 27.9 $ 22.8 $ 20.2 Deferred Compensation Plan We maintain a non-qualified deferred compensation plan, known as the Supplemental Savings Plan (SSP), that allows a select group of management employees in the U.S.to defer a portion of their compensation. The SSP also provides certain credits to highly compensated U.S.employees, which are paid by the company. These credits are known as the Restoration Match. The deferred compensation amounts are accrued when earned. Such deferred compensation is distributable in cash in accordance with the rules of the SSP. Deferred compensation amounts under such plan as of December31, 2009 and 2008 totaled approximately $63.6million and $48.5million, respectively, and are included in other long-term liabilities in the accompanying consolidated balance sheets. The SSP also holds certain transition contributions on behalf of participants who previously participated in the Biogen, Inc. Retirement Plan. Beginning in 2008, the Restoration Match vests immediately. Previously, the Restoration Match and transition contributions vested over four and seven years of service, respectively, by the employee. Participant contributions vest immediately. Distributions to participants can be either in one lump sum payment or annual installments as elected by the participants. Pension Plan We currently maintain retiree benefit plans which include, a defined benefit plan for employees in our German affiliate and other insignificant defined benefit plans in certain other countries in which we have an operating presence. The obligations under the German plan totaled $5.7million and $4.8million as of December31, 2009 and 2008, respectively. For the Years Ended December31, (In millions) 2009 2008 2007 Net periodic pension cost related to the German plan $ 1.1 $ 1.0 $ 1.3

Income Taxes

Income Taxes
	12 Months Ended Dec. 31, 2009 USD / shares
Income Taxes [Abstract]
Income Taxes	16. Income Taxes Income Tax Expense Income before income tax provision and the income tax expense consist of the following: For the Years Ended December31, (In millions) 2009 2008 2007 Income before income taxes (benefit): Domestic $ 1,073.8 $ 829.2 $ 664.9 Foreign 258.9 326.7 187.3 Total $ 1,332.7 $ 1,155.9 $ 852.2 Income tax expense (benefit): Current Federal $ 439.9 $ 431.2 $ 305.9 State 3.1 24.3 25.8 Foreign 50.0 49.8 22.3 Total $ 493.0 $ 505.3 $ 354.0 Deferred Federal $ (94.8 ) $ (119.2 ) $ (76.7 ) State (39.0 ) (20.0 ) (4.4 ) Foreign (3.6 ) (0.3 ) (0.5 ) Total $ (137.4 ) $ (139.5 ) $ (81.6 ) Total income tax expense $ 355.6 $ 365.8 $ 272.4 Deferred Tax Assets and Liabilities Significant components of our deferred tax assets and liabilities are summarized as follows: As of December31, (In millions) 2009 2008 Tax credits $ 35.2 $ 11.0 Inventory, deferred revenue and other reserves 166.4 90.4 Capitalized costs 8.7 36.6 Intangibles, net 83.2 89.6 Net operating loss 30.5 33.1 Share-based compensation 60.8 59.9 Other 60.6 57.9 Deferred tax assets $ 445.4 $ 378.5 Purchased intangible assets $ (475.4 ) $ (552.7 ) Unrealized gain on investments and cumulative translation adjustment (6.3 ) (2.3 ) Depreciation, amortization and other (115.6 ) (108.7 ) Deferred tax liabilities $ (597.3 ) $ (663.7 ) Tax Rate Reconciliation between the U.S.federal statutory tax rate and our effective tax rate is summarized as follows: For the Years Ended December31, (In percentages) 2009 2008 2007 Statutory rate 35.0 % 35.0 % 35.0 % State taxes (0.1 ) 1.6 3.2 Taxes on foreign earnings (5.0 ) (5.8 ) (8.1 ) Credits and net operating loss utilization (3.8

Collaborations

Collaborations
	12 Months Ended Dec. 31, 2009 USD / shares
Collaborations [Abstract]
Collaborations	17. Collaborations In connection with our business strategy, we have entered into various collaboration agreements which provide us with rights to develop, produce and market products using certain know-how, technology and patent rights maintained by our collaborative partners. Terms of the various collaboration agreements may require us to make milestone payments upon the achievement of certain product research and development objectives and pay royalties on future sales, if any, of commercial products resulting from the collaboration. Effective January1, 2009, we adopted a newly issued accounting standard for the accounting and disclosure of an entitys collaborative arrangements. This newly issued standard prescribes that certain transactions between collaborators be recorded in the income statement on either a gross or net basis, depending on the characteristics of the collaboration relationship, and provides for enhanced disclosure of collaborative relationships. In accordance with this guidance, we must also evaluate our collaborative agreements for proper income statement classification based on the nature of the underlying activity. Amounts due from our collaborative partners related to development activities are generally reflected as a reduction of research and development expense because the performance of contract development services is not central to our operations. For collaborations with commercialized products, if we are the principal (as defined in reporting revenue as a principal versus net as an agent as required by the Revenue Recognition Topic of the Codification) we record revenue and the corresponding operating costs in their respective line items within our consolidated statements of income. If we are not the principal, we record operating costs as a reduction of revenue. The guidance describes the principal as the party who is responsible for delivering the product or service to the customer, has latitude to determine price, and has the risks and rewards of providing product or service to the customer, including inventory and credit risk. The adoption of this newly issued accounting standard did not impact our financial position or results of operations; however it resulted in enhanced disclosures for our collaboration activities. Roche Group Genentech We collaborate with the Roche Group, through its wholly-owned member Genentech, Inc., on the development and commercialization of RITUXAN. We also have rights to collaborate with Genentech on the development and commercialization of (1)anti-CD20 products that Genentech acquires or develops, which we refer to as New Anti-CD20 Products, and (2)anti-CD20 products that Genentech licenses from a third party, which we refer to as Third Party Anti-CD20 Products. Currently, there is only one New Anti-CD20 Product, ocrelizumab, and only one Third Party Anti-CD20 Product, GA101. Our collaboration rights for New Anti-CD20 Products are limited to the U.S.and our collaboration rights for Third Party Anti-CD20 Products are dependent upon Genentechs underlying license rights. A joint development committee (JDC) composed of three members from each company

Commitments and Contingencies

Commitments and Contingencies
	12 Months Ended Dec. 31, 2009 USD / shares
Commitments and Contingencies [Abstract]
Commitments and Contingencies	18. Commitments and Contingencies Leases We rent laboratory and office space and certain equipment under noncancellable operating leases. These lease agreements contain various clauses for renewal at our option and, in certain cases, escalation clauses typically linked to rates of inflation. Rental expense under these leases, which terminate at various dates through 2025, amounted to $36.4million in 2009, $36.0million in 2008, and $33.1million in 2007. As of December31, 2009, minimum rental commitments under noncancellable leases for each of the next five years and total thereafter were as follows: (In millions) 2010 2011 2012 2013 2014 Thereafter Total Minimum lease payments(1) $ 33.0 $ 33.1 $ 29.9 $ 29.8 $ 28.7 $ 227.3 $ 381.8 Income from subleases (0.7 ) (0.7 ) Net minimum lease payments $ 32.3 $ 33.1 $ 29.9 $ 29.8 $ 28.7 $ 227.3 $ 381.1 (1) Includes fifteen-year lease on a 356,000square foot office building in Weston, Massachusetts, which will serve as the future location of our general and administrative offices with a planned occupancy around mid-year 2010. The initial lease term is from 2010 through 2025 under which the total minimum lease payments are $258.6million. Other Funding Commitments As of December31, 2009, we have funding commitments of up to approximately $24.8million in biotechnology oriented venture capital funds. As of December31, 2009, we have accrued expenses totaling approximately $31.7million on our consolidated balance sheet related to clinical research organizations for expenditures incurred in relation to ongoing clinical trials. Contingent Milestone Payments Based on our development plans as of December31, 2009, we have committed to make potential future milestone payments to third parties of up to approximately $1,500.0million as part of our various collaborations, including licensing and development programs. Payments under these agreements generally become due and payable only upon achievement of certain developmental, regulatory or commercial milestones. Because the achievement of these milestones had not occurred as of December31, 2009, such contingencies have not been recorded in our financial statements.

Litigation

Litigation
	12 Months Ended Dec. 31, 2009 USD / shares
Litigation [Abstract]
Litigation	19. Litigation Along with several other major pharmaceutical and biotechnology companies, Biogen, Inc. (now Biogen Idec MA, Inc., one of our wholly-owned subsidiaries) or, in some cases, Biogen Idec Inc., was named as a defendant in lawsuits filed by the City of New York and numerous Counties of the State of New York. All of the cases except for cases filed by the County of Erie, County of Oswego and County of Schenectady (Three County Actions) are the subject of a Consolidated Complaint, first filed on September15, 2005 in the U.S.District Court for the District of Massachusetts in Multi-District Litigation No.1456 (MDL proceedings). The complaints allege that the defendants (i)fraudulently reported (or caused others to report incorrectly) the Average Wholesale Price for certain drugs for which Medicaid provides reimbursement (Covered Drugs); (ii)marketed and promoted the sale of Covered Drugs to providers based on the providers ability to collect inflated payments from the government and Medicaid beneficiaries that exceeded payments possible for competing drugs; (iii)provided financing incentives to providers to over-prescribe Covered Drugs or to prescribe Covered Drugs in place of competing drugs; and (iv)overcharged Medicaid for illegally inflated Covered Drugs reimbursements. Among other things, the complaints allege violations of New York state law and advance common law claims for unfair trade practices, fraud, and unjust enrichment. In addition, the amended Consolidated Complaint alleges that the defendants failed to accurately report the best price on the Covered Drugs to the Secretary of Health and Human Services pursuant to rebate agreements, and excluded from their reporting certain discounts and other rebates that would have reduced the best price. With respect to the MDL proceedings, some of the plaintiffs claims were dismissed, and the parties, including Biogen Idec, began a mediation of the outstanding claims on July1, 2008. We have not formed an opinion that an unfavorable outcome is either probable or remote in any of these cases, and do not express an opinion at this time as to their likely outcome or as to the magnitude or range of any potential loss. We believe that we have good and valid defenses to each of these complaints and are vigorously defending against them. In 2006, the Massachusetts Department of Revenue (DOR) issued a notice of assessment against Biogen Idec MA, Inc. for $38.9million of corporate excise tax with respect to the 2002 tax year, which includes associated interest and penalties. On December6, 2006, we filed an abatement application with the DOR, seeking abatements for 2001, 2002 and 2003 tax years. The abatement application was denied on July24, 2007. On July25, 2007, we filed a petition with the Massachusetts Appellate Tax Board, seeking, among other items, abatements of corporate excise tax for 2001, 2002 and 2003 tax years and adjustments in certain credits and credit carry forwards for 2001, 2002 and 2003 tax years. Issues before the Board include the computation of Biogen Idec MAs sales factor for 2001, 2002 and 2003 tax years, computation of Biogen Idec MAs research credi

Segment Information

Segment Information
	12 Months Ended Dec. 31, 2009 USD / shares
Segment Information [Abstract]
Segment Information	20. Segment Information We operate in one business segment, which is the business of development, manufacturing and commercialization of novel therapeutics for human healthcare and, therefore, our chief operating decision-maker manages the operations of our Company as a single operating segment. Enterprise-wide disclosures about product revenues, other revenues and long-lived assets by geographic area and information relating to major customers are presented below. Revenues are primarily attributed to individual countries based on location of the customer or licensee. Revenue by product is summarized as follows: For the Years Ended December31, 2009 2008 2007 United Rest of United Rest of United Rest of (In millions) States World Total States World Total States World Total AVONEX $ 1,406.2 $ 916.7 $ 2,322.9 $ 1,276.5 $ 926.1 $ 2,202.6 $ 1,085.0 $ 782.8 $ 1,867.8 TYSABRI 231.8 544.2 776.0 196.4 392.2 588.6 104.4 125.5 229.9 Other 54.0 54.0 48.5 48.5 14.2 24.9 39.1 Total product revenues $ 1,638.0 $ 1,514.9 $ 3,152.9 $ 1,472.9 $ 1,366.8 $ 2,839.7 $ 1,203.6 $ 933.2 $ 2,136.8 Our geographic information is summarized as follows (in millions): December31, 2009 U.S. Europe Germany Asia Other Total Product revenues from external customers $ 1,638.0 $ 913.7 $ 374.8 $ 47.9 $ 178.5 $ 3,152.9 Revenues from unconsolidated joint business $ 839.2 $ 190.2 $ $ 24.1 $ 41.4 $ 1,094.9 Other revenues from external customers $ 102.8 $ 26.2 $ 0.5 $ $ $ 129.5 Long-lived assets $ 1,092.7 $ 705.6 $ 1.4 $ 3.6 $ 2.1 $ 1,805.4 December31, 2008 U.S. Europe Germany Asia Other Total Product revenues from external customers $ 1,472.9 $ 822.6 $ 354.5 $ 36.5 $ 153.2 $ 2,839.7 Revenues from unconsolidated joint business $ 793.2 $ 272.3 $ $ 21.7 $ 41.0 $ 1,128.2 Other revenues from exte

Guarantees

Guarantees
	12 Months Ended Dec. 31, 2009 USD / shares
Guarantees [Abstract]
Guarantees	21. Guarantees As of December31, 2009 and 2008, we did not have significant liabilities recorded for guarantees. We enter into indemnification provisions under our agreements with other companies in the ordinary course of business, typically with business partners, contractors, clinical sites and customers. Under these provisions, we generally indemnify and hold harmless the indemnified party for losses suffered or incurred by the indemnified party as a result of our activities. These indemnification provisions generally survive termination of the underlying agreement. The maximum potential amount of future payments we could be required to make under these indemnification provisions is unlimited. However, to date we have not incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. As a result, the estimated fair value of these agreements is minimal. Accordingly, we have no liabilities recorded for these agreements as of December31, 2009 and 2008, respectively.

Quarterly Financial Data

Quarterly Financial Data (Unaudited)
	12 Months Ended Dec. 31, 2009 USD / shares
Quarterly Financial Data (Unaudited) [Abstract]
Quarterly Financial Data (Unaudited)	22. Quarterly Financial Data (Unaudited) First Second Third Fourth Total (In millions, except per share amounts) Quarter(b) Quarter(c) Quarter Quarter(d)(e) Year 2009 Product revenues $ 733.4 $ 791.0 $ 801.7 $ 826.8 $ 3,152.9 Unconsolidated joint business revenues $ 278.8 $ 275.6 $ 283.9 $ 256.6 $ 1,094.9 Other revenues $ 24.3 $ 26.7 $ 34.9 $ 43.6 $ 129.5 Total revenues $ 1,036.5 $ 1,093.3 $ 1,120.5 $ 1,127.0 $ 4,377.3 Total costs and expenses and income tax expense $ 796.8 $ 963.1 $ 850.3 $ 827.3 $ 3,437.5 Other income (expense), net $ 6.8 $ 14.7 $ 9.4 $ 6.4 $ 37.3 Net income attributable to Biogen Idec Inc. $ 244.0 $ 142.8 $ 277.7 $ 305.6 $ 970.1 Basic earnings per share attributable to Biogen Idec Inc. $ 0.85 $ 0.49 $ 0.96 $ 1.07 $ 3.37 Diluted earnings per share attributable to Biogen Idec Inc. $ 0.84 $ 0.49 $ 0.95 $ 1.06 $ 3.35 First Second Third Fourth Total (In millions, except per share amounts) Quarter(a) Quarter Quarter Quarter Year 2008 Product revenues $ 665.1 $ 684.5 $ 758.3 $ 731.8 $ 2,839.7 Unconsolidated joint business revenues $ 247.2 $ 278.8 $ 299.0 $ 303.2 $ 1,128.2 Other revenues $ 29.9 $ 30.1 $ 35.7 $ 33.9 $ 129.6 Total revenues $ 942.2 $ 993.4 $ 1,093.0 $ 1,068.9 $ 4,097.5 Total costs and expenses and income tax expense $ 779.5 $ 781.4 $ 861.5 $ 827.3 $ 3,249.7 Other income (expense), net $ 3.1 $ (4.0 ) $ (23.7 ) $ (33.1 ) $ (57.7 ) Net income attributable to Biogen Idec Inc. $ 163.1 $ 206.6 $ 206.8 $ 206.7 $ 783.2 Basic earnings per share attributable to Biogen Idec Inc. $ 0.55 $ 0.71 $ 0.71 $ 0.71 $ 2.67 Diluted earnings per share attributable to Biogen Idec Inc. $ 0.54 $ 0.70 $ 0.70 $ 0.70 $ 2.65 (a) Total costs and expenses and income tax expense for the first quarter of 2008 includes $25.0million of in-pro

New Accounting Pronouncements

New Accounting Pronouncements
	12 Months Ended Dec. 31, 2009 USD / shares
New Accounting Pronouncements [Abstract]
New Accounting Pronouncements	23. New Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption. Recently Issued Accounting Standards In October 2009, the FASB issued Accounting Standards Update (ASU) No.2009-13, Multiple-Deliverable Revenue Arrangements (ASU No.2009-13). ASU No.2009-13, which amends existing revenue recognition accounting pronouncements and provides accounting principles and application guidance on whether multiple deliverables exist, how the arrangement should be separated, and the consideration allocated. This guidance eliminates the requirement to establish the fair value of undelivered products and services and instead provides for separate revenue recognition based upon managements estimate of the selling price for an undelivered item when there is no other means to determine the fair value of that undelivered item. Previous accounting principles required that the fair value of the undelivered item be the price of the item either sold in a separate transaction between unrelated third parties or the price charged for each item when the item is sold separately by the vendor. This was difficult to determine when the product was not individually sold because of its unique features. If the fair value of all of the elements in the arrangement was not determinable, then revenue was deferred until all of the items were delivered or fair value was determined. This new approach is effective prospectively for revenue arrangements entered into or materially modified in fiscal years beginning on or after June15, 2010, which for Biogen Idec means no later than January1, 2011. Early adoption is permitted; however, adoption of this guidance as of a date other than January1, 2011, will require us to apply this guidance retrospectively effective as of January1, 2010 and will require disclosure of the effect of this guidance as applied to all previously reported interim periods in the fiscal year of adoption. While we do not expect the adoption of this standard to have a material impact on our financial position and results of operations, this standard may impact us in the event we complete future transactions or modify existing collaborative relationships. In June 2009, the FASB issued the following two new accounting standards, which were integrated into the Codification in December 2009: ASU No.2009-16, Accounting for Transfers of Financial Assets (ASU No.2009-16);and ASU No.2009-17, Improvements to Financial Reporting by Enterprises Involved with Variable Interest Entities (ASU No.2009-17). ASU No.2009-16 prescribes the information that a reporting entity must provide in its financial reports about a transfer of financial assets; the effects of a transfer on its financial position, financial performance, and cash flows; and a transferors continuing involvem