Sale of Commercial Business - Schedule of Discontinued Operations and Assets Held for Sale (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other income and expenses:
Income tax expense	$ (51,900)		$ (51,900)
Total income (loss) from discontinued operations	540,485	$ 675	539,538	$ (268)
Commercial Business [Member]
Revenues:
Product revenues, net		12,851	16,135	22,819
License and collaboration revenues		19,332	7,797	30,645
Other revenues		1,498	1,973	1,498
Total revenues		33,681	25,905	54,962
Costs and expenses:
Cost of revenues		1,872	3,890	2,583
Research and development expenses		13,302	3,700	18,181
Selling, general and administrative expenses		12,542	8,709	23,885
Restructuring expenses	4,216		9,535
Total costs and expenses	4,216	27,716	25,834	44,649
Other income and expenses:
Interest expense	(1,509)	(5,290)	(6,743)	(10,581)
Gain on sale of commercial business	598,120		598,120
Income (loss) from discontinued operations	592,395	675	591,448	(268)
Income tax expense	(51,910)		(51,910)
Total income (loss) from discontinued operations	$ 540,485	$ 675	$ 539,538	$ (268)