Organization and Summary of Significant Accounting Policies - Impact of Adoption of ASC 606 on Condensed Consolidated Balance Sheet and Condensed Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Condensed Consolidated Balance Sheet data
Accounts receivable, net	$ 31,937		$ 31,937		$ 5,014
Deferred revenue, current portion	15,676		15,676		18,949
Deferred revenue, less current portion	11,410		11,410		19,021
Accumulated deficit	(1,325,839)		(1,325,839)		$ (2,117,941)
Condensed Consolidated Statement of Operations data
Total revenue	27,762	$ 152,928	1,153,497	$ 212,245
Royalty [Member]
Condensed Consolidated Statement of Operations data
Total revenue	10,259	9,302	29,898	23,953
License, Collaboration and Other Revenue [Member]
Condensed Consolidated Statement of Operations data
Total revenue	4,875	131,112	1,082,848	142,028
Product Sales [Member]
Condensed Consolidated Statement of Operations data
Total revenue	4,256	$ 4,448	16,414	$ 24,897
ASC 606 [Member] | Adjustments [Member]
Condensed Consolidated Balance Sheet data
Accounts receivable, net	(10,549)		(10,549)
Deferred revenue, current portion	1,191		1,191
Deferred revenue, less current portion	187		187
Accumulated deficit	(11,927)		(11,927)
Condensed Consolidated Statement of Operations data
Total revenue	(375)		770
ASC 606 [Member] | Adjustments [Member] | Royalty [Member]
Condensed Consolidated Statement of Operations data
Total revenue	(674)		195
ASC 606 [Member] | Adjustments [Member] | License, Collaboration and Other Revenue [Member]
Condensed Consolidated Statement of Operations data
Total revenue	299		767
ASC 606 [Member] | Adjustments [Member] | Product Sales [Member]
Condensed Consolidated Statement of Operations data
Total revenue	0		(192)
ASC 606 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Condensed Consolidated Balance Sheet data
Accounts receivable, net	21,388		21,388
Deferred revenue, current portion	16,867		16,867
Deferred revenue, less current portion	11,597		11,597
Accumulated deficit	(1,337,766)		(1,337,766)
Condensed Consolidated Statement of Operations data
Total revenue	27,387		1,154,267
ASC 606 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Royalty [Member]
Condensed Consolidated Statement of Operations data
Total revenue	9,585		30,093
ASC 606 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | License, Collaboration and Other Revenue [Member]
Condensed Consolidated Statement of Operations data
Total revenue	5,174		1,083,615
ASC 606 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Product Sales [Member]
Condensed Consolidated Statement of Operations data
Total revenue	$ 4,256		$ 16,222