Revenue from Different Products Restated (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue from External Customer [Line Items]
Revenues	$ 26,311	$ 26,099	$ 29,264	$ 26,509	$ 17,724	$ 19,253	$ 19,436	$ 17,612	$ 55,773	$ 37,048	$ 81,872	$ 56,301	$ 108,183	$ 74,025	$ 66,804
Feature Phone
Revenue from External Customer [Line Items]
Revenues													13,135	31,091	54,475
Smartphone
Revenue from External Customer [Line Items]
Revenues													$ 95,048	$ 42,934	$ 12,329