Revenue from Contracts with Customers - Schedule of Revenue from Contracts with Customers Impacts (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 01, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Assets
Accounts receivable, net		$ 152,520		$ 152,520		$ 84,774
Prepaid expenses and other current assets		26,180		26,180		19,138
Liabilities
Current portion of deferred revenue		36,495		36,495		34,457
Deferred revenue, less current portion		6,004		6,004		30,618
Stockholders’ equity:
Accumulated deficit		(1,204,783)		(1,204,783)		$ (1,192,570)
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues		169,424	$ 135,291	480,187	$ 352,645
Net income (loss)		(67,446)	50,021	(102,888)	(66,329)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Assets
Accounts receivable, net		(16,730)		(16,730)
Prepaid expenses and other current assets		(990)		(990)
Liabilities
Current portion of deferred revenue		(99)		(99)
Deferred revenue, less current portion		(16)		(16)
Stockholders’ equity:
Accumulated deficit	$ 26,556	(17,605)		(17,605)
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues		5,701		9,586
Net income (loss)		4,875		8,952
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Assets
Accounts receivable, net		135,790		135,790
Prepaid expenses and other current assets		25,190		25,190
Liabilities
Current portion of deferred revenue		36,396		36,396
Deferred revenue, less current portion		5,988		5,988
Stockholders’ equity:
Accumulated deficit		(1,222,388)		(1,222,388)
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues		175,125		489,773
Net income (loss)		(62,571)		(93,936)
License and Service [Member]
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues		19,786	39,444	76,524	82,779
License and Service [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues	10,281	7,448		9,407
License and Service [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues		27,234		85,931
Royalty [Member]
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues		22,662	16,670	58,887	46,025
Cost of sales		5,320	$ 5,196	16,845	$ 13,900
Royalty [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues	$ 22,230	(1,747)		179
Cost of sales		826		634
Royalty [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Condensed Consolidated Statements of Comprehensive Loss data:
Total revenues		20,915		59,066
Cost of sales		$ 6,146		$ 17,479