Business and Basis of Presentation - Restatement Corrections and Other Immaterial Adjustments on Consolidated Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
As Reported [Member]
Deferred tax asset	$ 13,785
Total current assets	213,040
Intangible assets, net	203,017	202,311
Deferred tax assets	4,813
Other assets	8,755	7,569
Goodwill	28,940	28,973
Total assets	460,569	506,274
Accounts payable and other accrued obligations	85,249	95,297
Accrued drug development costs	12,896	15,109
Total current liabilities	107,759	128,397
Total liabilities	182,969	221,428
Accumulated deficit	(192,286)	(179,320)
Total stockholders' equity	277,600	284,846
As Restated [Member]
Deferred tax asset	13,027	12,473
Total current assets	212,282	264,873
Intangible assets, net	196,786	200,234
Deferred tax assets	29,676	23,276
Other assets	8,755	6,745
Goodwill	7,246	7,279
Total assets	456,749	504,955
Accounts payable and other accrued obligations	83,592	93,811
Accrued drug development costs	9,089	11,441
Total current liabilities	102,295	123,243
Total liabilities	177,505	216,274
Accumulated deficit	(190,642)	(175,485)
Total stockholders' equity	$ 279,244	$ 288,681