Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash Flows From Investing Activities:
Acquisition of Melphalan license	$ (3,000,000)
Cash Flows From Financing Activities:
Cash and cash equivalents-beginning of period	139,698,000
Cash and cash equivalents-end of period	121,103,000
As Restated [Member]
Cash Flows From Operating Activities:
Net (loss) income	(15,157,000)	65,187,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization of deferred revenue	(10,300,000)	(6,150,000)
Depreciation and amortization	10,772,000	4,043,000
Stock-based compensation	5,671,000	6,097,000
Deferred income tax benefit	(6,039,000)	(31,493,000)
Provision (recovery) for bad debt	44,000	(31,000)
Provision for inventory obsolescence	1,041,000	437,000
Change in fair value of Allos deferred development costs and deferred payment contingency	(2,869,000)
Impairment of intangible assets	1,023,000
Foreign currency remeasurement loss	654,000	1,354,000
Excess tax benefits from share-based compensation		(2,181,000)
Changes in operating assets and liabilities:
Accounts receivable, net	39,746,000	(33,105,000)
Inventories, net	(1,875,000)	2,639,000
Prepaid expenses and other assets	(5,691,000)	(950,000)
Accounts payable and other accrued obligations	(11,495,000)	36,489,000
Accrued compensation and related expenses	(472,000)	1,717,000
Accrued drug development costs	(2,352,000)	277,000
Deferred revenue and other credits	743,000	619,000
Net cash provided by operating activities	3,444,000	44,949,000
Cash Flows From Investing Activities:
Sales and maturities of marketable securities		57,797,000
Purchases of marketable securities		(11,944,000)
Acquisition of Melphalan license	(3,000,000)
Purchases of property and equipment	(127,000)	(302,000)
Purchases of available for sale securities		(622,000)
Acquisition of ZEVALIN Rights		(25,435,000)
Net cash (used in) provided by investing activities	(3,127,000)	19,494,000
Cash Flows From Financing Activities:
Proceeds from issuance of common stock from stock option exercises	1,137,000	2,523,000
Proceeds from contributions to ESPP	197,000	372,000
Payments to acquire treasury stock	(1,652,000)	(317,000)
Repurchase of shares to satisfy minimum tax withholding for restricted stock vesting	(410,000)	(326,000)
Proceeds from Munidpharma collaboration amendment	7,000,000
Proceeds from revolving line of credit	100,000,000
Repayment of revolving line of credit	(125,000,000)
Repayment of capital leases		(9,000)
Excess tax benefits from share-based compensation		2,181,000
Net cash (used in) provided by financing activities	(18,728,000)	4,424,000
Effect of exchange rates on cash	(184,000)	85,000
Net (decrease) increase in cash and cash equivalents	(18,595,000)	68,952,000
Cash and cash equivalents-beginning of period	139,698,000	121,202,000
Cash and cash equivalents-end of period	121,103,000	190,154,000
Supplemental Disclosure of Cash Flow Information:
Melphalan license included in intangible assets and other long term obligations	4,700,000
Inventory liability assumed in acquisition		580,000
Retirement of treasury shares	$ 1,652,000