Acquisitions - Schedule of Unaudited Pro forma Results of Operations (Detail) (Allos Therapeutics, Inc. [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011
Allos Therapeutics, Inc. [Member]
Business Acquisition [Line Items]
Total revenues	$ 299,116	$ 269,012
Income from continuing operations	56,309	21,639
Net income	$ 64,732	$ 12,368
Basic net income per share	$ 1.10	$ 0.23
Diluted net income per share	$ 1.00	$ 0.21

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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