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								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Consolidated Balance Sheet data
Accounts receivable, net	$ 43,213				$ 5,014				$ 43,213	$ 5,014
Deferred revenue, current portion	13,892				18,949				13,892	18,949
Deferred revenue, less current portion	10,744				19,021				10,744	19,021
Accumulated deficit	(1,424,051)				(2,117,941)				(1,424,051)	(2,117,941)
Condensed Consolidated Statement of Operations data
Total revenue	39,826	$ 27,762	$ 1,087,717	$ 38,018	95,466	$ 152,928	$ 34,589	$ 24,728	1,193,323	307,711	$ 165,436
Product Sales [Member]
Condensed Consolidated Statement of Operations data
Total revenue	4,360	$ 4,256	$ 5,863	$ 6,295	$ 7,791	$ 4,448	$ 15,693	$ 4,756	20,774	32,688	55,354
Royalty [Member]
Condensed Consolidated Statement of Operations data
Total revenue									41,976	33,527	19,542
License, Collaboration and Other Revenue [Member]
Condensed Consolidated Statement of Operations data
Total revenue									1,097,265	$ 210,965	$ 60,382
ASC 606 [Member] | Adjustments [Member]
Condensed Consolidated Balance Sheet data
Accounts receivable, net	(21,030)								(21,030)
Deferred revenue, current portion	1,191								1,191
Deferred revenue, less current portion	(112)								(112)
Accumulated deficit	(22,109)								(22,109)
Condensed Consolidated Statement of Operations data
Total revenue									(9,412)
ASC 606 [Member] | Adjustments [Member] | Product Sales [Member]
Condensed Consolidated Statement of Operations data
Total revenue									(192)
ASC 606 [Member] | Adjustments [Member] | Royalty [Member]
Condensed Consolidated Statement of Operations data
Total revenue									(286)
ASC 606 [Member] | Adjustments [Member] | License, Collaboration and Other Revenue [Member]
Condensed Consolidated Statement of Operations data
Total revenue									(8,934)
ASC 606 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Condensed Consolidated Balance Sheet data
Accounts receivable, net	22,183								22,183
Deferred revenue, current portion	15,083								15,083
Deferred revenue, less current portion	10,632								10,632
Accumulated deficit	$ (1,446,160)								(1,446,160)
Condensed Consolidated Statement of Operations data
Total revenue									1,183,911
ASC 606 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Product Sales [Member]
Condensed Consolidated Statement of Operations data
Total revenue									20,582
ASC 606 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Royalty [Member]
Condensed Consolidated Statement of Operations data
Total revenue									41,690
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									$ 1,088,331