Business Combination - Additional Information (Details) (BCD Semiconductor Manufacturing Limited, USD $)	0 Months Ended	12 Months Ended
	Mar. 05, 2013	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Mar. 05, 2013
Business Acquisition, Cost of Acquired Entity, Description of Purchase Price Components		we completed the acquisition of all the outstanding ordinary shares, par value $0.001 per share, of BCD (the “Shares”), including Shares represented by American Depository Shares (“ADSs”), which were cancelled in exchange for the right to receive $1.33-1/3 in cash per Share, without interest. Each ADS represented six Shares and was converted into the right to receive $8.00 in cash, without interest. The aggregate consideration was approximately $155 million, excluding acquisition costs, fees and expenses. In addition, a $5 million retention plan for BCD employees, payable at the 12, 18 and 24 month anniversaries of the acquisition, was established.
Retention Payable	$ 5,000,000
Business Acquisition, Share Price	$ 0.001
Exchange Rights Value Of Shares	$ 8.00
Aggregate consideration, excluding acquisition costs, fees and expenses	154,735,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual			155,000,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual			6,000,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Description		The step acquisition guidelines also require us to remeasure the preexisting investment in BCD at fair value, and recognize any gains or losses from such remeasurement. The fair value of our interest immediately before the closing date was $7 million, which resulted in us recognizing a non-cash gain of approximately $4 million within other income (expense) for the year ended December 31, 2013.
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value			7,000,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain			4,000,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Valuation Techniques		The shares of BCD common stock were valued under the fair value hierarchy as a Level 1 Input.
Business Acquisition, Purchase Price Allocation, Methodology		The fair value of the significant identified intangible assets was estimated by using the market approach, income approach and cost approach valuation methodologies. Inputs used in the methodologies primarily included projected future cash flows, discounted at a rate commensurate with the risk involved.
Acquired Finite-lived Intangible Asset, Amount		17,000,000
Acquired Finite-lived Intangible Asset, Residual Value		0
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		6 years
Business Acquisition, Purchase Price Allocation, Goodwill, Expected Tax Deductible Amount, Description		goodwill is not deductible for income tax purposes.
Business Combination, Acquired Receivables, Fair Value		21,000,000
Business Combination, Acquired Receivables, Gross Contractual Amount		21,000,000
Acquired Inventory Adjustments		5,000,000
Acquired Inventory Expenses To Cost Of Goods Sold				$ 3,000,000	$ 2,000,000
Business Combination, Acquired Receivables, Description		We estimated the fair value of acquired receivables to be $21 million with a gross contractual amount of $21million. We expected to collect substantially all of the acquired receivables.
Acquired Inventory Reasonable Profit Allowance		We evaluated and adjusted the acquired inventory for a reasonable profit allowance, which is intended to permit us to report only the profits normally associated with the activities following the acquisition as it relates to the work-in-progress and finished goods inventory. As such, we increased the inventory acquired from BCD by approximately $5 million, and recorded that increase into cost of goods sold, of which approximately $2 million was recorded in the first quarter of 2013 and $3 million was recorded in the second quarter of 2013 as the acquired work-in-progress and finished goods inventory was sold.
Business Acquisition, Pro Forma Information, Description		The following unaudited pro forma consolidated results of operations for the year ended December 31, 2013 have been prepared as if the acquisition of BCD had occurred at January 1,2012. The unaudited pro forma consolidated results of operations do not purport to be indicative of the results that would have been obtained if the above acquisition had actually occurred as of the dates indicated or of those results that may be obtained in the future. These unaudited pro forma consolidated results of operations were derived, in part, from the historical consolidated financial statements of BCD and other available information and assumptions believed to be reasonable under the circumstances.
Maximum
Business Acquisition [Line Items]
Right to receive, cash per Share	$ 1.33
Minimum
Business Acquisition [Line Items]
Right to receive, cash per Share	$ 0.33