Segment And Geographic Information - Schedule of Geographic Revenue Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 46,614	$ 58,315	$ 75,278	$ 101,853
Percentage of revenue	100.00%	100.00%	100.00%	100.00%
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
U.S. revenues	21,925	26,427	27,535	43,947
Percentage of revenue	47.00%	46.00%	36.00%	43.00%
Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Foreign revenues	15,642	13,097	32,028	19,480
Percentage of revenue	34.00%	22.00%	43.00%	19.00%
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Foreign revenues	4,425	5,770	9,289	11,234
Percentage of revenue	9.00%	10.00%	12.00%	11.00%
Other Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Foreign revenues	3,836	11,059	5,274	23,997
Percentage of revenue	8.00%	19.00%	7.00%	24.00%
Europe and Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Foreign revenues	$ 786	$ 1,962	$ 1,152	$ 3,195
Percentage of revenue	2.00%	3.00%	2.00%	3.00%