Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash Flows From Operating Activities:
Net (loss) income	$ (12,966)	$ 64,612
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization of deferred revenue	(10,300)	(6,150)
Depreciation and amortization	6,618	4,043
Stock-based compensation	5,671	6,097
Deferred income tax benefit	(6,039)	(31,493)
Provision (recovery) for bad debt	44	(31)
Provision for inventory obsolescence	1,041	437
Change in fair value of Allos deferred development costs and deferred payment contingency	(2,869)
Impairment of intangible assets	1,023
Foreign currency remeasurement loss	654	1,354
Excess tax benefits from share-based compensation		(2,181)
Changes in operating assets and liabilities:
Accounts receivable, net	39,746	(33,105)
Inventories, net	(1,875)	2,639
Prepaid expenses and other assets	(5,691)	(950)
Accounts payable and other accrued obligations	(9,671)	36,409
Accrued compensation and related expenses	(472)	1,717
Accrued drug development costs	(2,213)	932
Deferred revenue and other credits	743	619
Net cash provided by operating activities	3,444	44,949
Cash Flows From Investing Activities:
Sales and maturities of marketable securities		57,797
Purchases of marketable securities		(11,944)
Acquisition of Melphalan license	(3,000)
Purchases of property and equipment	(127)	(302)
Purchases of available for sale securities		(622)
Acquisition of ZEVALIN Rights		(25,435)
Net cash (used in) provided by investing activities	(3,127)	19,494
Cash Flows From Financing Activities:
Proceeds from issuance of common stock from stock option exercises	1,137	2,523
Proceeds from contributions to ESPP	197	372
Payments to acquire treasury stock	(1,652)	(317)
Repurchase of shares to satisfy minimum tax withholding for restricted stock vesting	(410)	(326)
Proceeds from Munidpharma collaboration amendment	7,000
Proceeds from revolving line of credit	100,000
Repayment of revolving line of credit	(125,000)
Repayment of capital leases		(9)
Excess tax benefits from share-based compensation		2,181
Net cash (used in) provided by financing activities	(18,728)	4,424
Effect of exchange rates on cash	(184)	85
Net (decrease) increase in cash and cash equivalents	(18,595)	68,952
Cash and cash equivalents-beginning of period	139,698	121,202
Cash and cash equivalents-end of period	121,103	190,154
Supplemental Disclosure of Cash Flow Information:
Melphalan license included in intangible assets and other long term obligations	4,700
Inventory liability assumed in acquisition		580
Retirement of treasury shares	$ 1,652