New Revenue Recognition Standard - Condensed Consolidated Statement of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Total revenues	$ 25,268	$ 36,395	$ 79,930	$ 99,797
Loss from operations	(29,024)	(15,054)	(88,600)	(55,572)
Loss before income taxes	(68,716)	(19,759)	(70,784)	(64,103)
Net loss	$ (68,718)	$ (18,293)	$ (70,792)	$ (62,691)
Net income per share:
Basic ($ per share)	$ (0.66)	$ (0.22)	$ (0.69)	$ (0.78)
Diluted ($ per share)	$ (0.66)	$ (0.22)	$ (0.69)	$ (0.78)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] \| Accounting Standards Update 2014-09 [Member]
Revenue:
Total revenues	$ 183		$ 1,808
Loss from operations	183		1,808
Loss before income taxes	183		1,808
Net loss	$ 183		$ 1,808
Net income per share:
Basic ($ per share)	$ 0.00		$ 0.02
Diluted ($ per share)	$ 0.00		$ 0.02
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue:
Total revenues	$ 25,451		$ 81,738
Loss from operations	(28,841)		(86,792)
Loss before income taxes	(68,533)		(68,976)
Net loss	$ (68,535)		$ (68,984)
Net income per share:
Basic ($ per share)	$ (0.66)		$ (0.67)
Diluted ($ per share)	$ (0.66)		$ (0.67)
Product [Member]
Revenue:
Total revenues	$ 24,556	$ 31,234	$ 76,419	$ 88,235
Product [Member] \| Difference between Revenue Guidance in Effect before and after Topic 606 [Member] \| Accounting Standards Update 2014-09 [Member]
Revenue:
Total revenues	424		1,985
Product [Member] \| Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue:
Total revenues	24,980		78,404
License and Service [Member]
Revenue:
Total revenues	712	$ 5,161	3,511	$ 11,562
License and Service [Member] \| Difference between Revenue Guidance in Effect before and after Topic 606 [Member] \| Accounting Standards Update 2014-09 [Member]
Revenue:
Total revenues	(241)		(177)
License and Service [Member] \| Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue:
Total revenues	$ 471		$ 3,334

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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