Organization and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) Share data in Millions, unless otherwise specified	12 Months Ended			1 Months Ended
	Dec. 31, 2014 Reporting_Unit Customer	Dec. 31, 2013 Customer	Dec. 31, 2012	Jul. 31, 2012	Jul. 11, 2012
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash and investments in marketable securities	$ 262,824,000	$ 262,026,000
Indebtedness	151,800,000
Senior secured notes, issued	125,000,000	125,000,000
Restricted cash	25,000,000
Maximum maturity term of investments in marketable securities to be considered as cash equivalents	Three months
Maturity term of investments considered as short-term	Less than one year
Number of customers accounted for major accounts receivable	3	3
Percentage of accounts receivable customers one	40.00%	30.00%
Percentage of accounts receivable customers two	31.00%	28.00%
Percentage of accounts receivable customers three	15.00%	28.00%
Number of reporting unit evaluated for goodwill	1
Reduction of prior periods research and development expenses	4,700,000
Minimum percentage of amount realized upon ultimate settlement	50.00%
Stock Options [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Weighted average diluted securities excluded from diluted net loss per share	21.9	20.7	18.8
Minimum [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives	3
Maximum [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives	7
12% Senior Secured Notes Due July 2017 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Senior secured notes, issued					125,000,000
Senior secured notes, interest rate	12.00%				12.00%
Senior secured notes, maturity date	Jul. 15, 2017			Jul. 15, 2017
Restricted cash	$ 25,000,000