Organization and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012 Customer	Dec. 31, 2011 Customer
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash, cash equivalents, and investments in marketable securities	$ 302,200,000
Indebtedness	149,000,000
Outstanding convertible subordinated notes		214,955,000
Senior secured notes, issued	125,000,000
Principal amount of the convertible subordinated notes, retired amount	214,955,000
Restricted cash and long-term investments	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	4	4
Percentage of accounts receivable customers one	38.00%	26.00%
Percentage of accounts receivable customers two	27.00%	20.00%
Percentage of accounts receivable customers three	14.00%	19.00%
Percentage of accounts receivable customers four	11.00%	17.00%
Minimum percentage of amount realized upon ultimate settlement	50.00%
12% Senior Secured Notes due July 2017 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Senior secured notes, interest rate	12.00%
Maturity date of senior secured notes	Jul. 15, 2017
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]
Contingent payment related to royalty obligation	$ 7,000,000
Property and Equipment estimated useful lives	7