Alpha and Omega Semiconductor Limited (AOSL) 10-Q 6 Nov 13 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Entity Information [Line Items]	'	'
Entity Registrant Name	'ALPHA & OMEGA SEMICONDUCTOR Ltd	'
Entity Central Index Key	'0001387467	'
Current Fiscal Year End Date	'--06-30	'
Entity Filer Category	'Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	25,706,052

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Jun. 30, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$95,995	$92,406
Restricted cash	245	204
Accounts receivable, net	40,949	38,298
Inventories	68,422	68,339
Deferred income tax assets	1,598	3,030
Other current assets	4,042	3,578
Total current assets	211,251	205,855
Property, plant and equipment, net	132,978	138,111
Intangible assets, net	392	496
Goodwill	269	269
Deferred income tax assets	10,685	10,823
Other long-term assets	844	767
Total assets	356,419	356,321
Current liabilities:	'	'
Short term debt	3,107	3,821
Accounts payable	32,789	31,738
Accrued liabilities	15,518	14,571
Income taxes payable	1,215	1,472
Deferred margin	625	622
Capital leases	934	1,267
Total current liabilities	54,188	53,491
Long-term debt	12,857	13,571
Income taxes payable - long term	3,498	3,692
Deferred income tax liabilities	1,421	2,613
Capital leases - long term	195	195
Deferred rent	1,268	1,308
Total liabilities	73,427	74,870
Commitments and contingencies (Note 9)	'	'
Preferred shares, par value $0.002 per share:	'	'
Authorized: 10,000 shares; Issued and outstanding: none at September 30, 2013 and June 30, 2013	0	0
Common shares, par value $0.002 per share:	'	'
Authorized: 50,000 shares; Issued and outstanding: 25,924 shares and 25,698 shares at September 30, 2013 and 25,882 shares and 25,656 shares at June 30, 2013	52	51
Treasury shares at cost; 226 shares at September 30, 2013 and June 30, 2013	-2,050	-2,054
Additional paid-in capital	169,531	168,352
Accumulated other comprehensive income	1,011	957
Retained earnings	114,448	114,145
Total shareholders’ equity	282,992	281,451
Total liabilities and shareholders’ equity	$356,419	$356,321

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Jun. 30, 2013
Common shares, par value (in dollars per share)	$0.00	$0.00
Common shares, authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	25,924,000	25,882,000
Common stock, shares outstanding (in shares)	25,698,000	25,656,000
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury shares (in shares)	226,000	226,000

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Revenue	$84,121	$95,761
Cost of goods sold	66,970	70,228
Gross profit	17,151	25,533
Operating expenses	'	'
Research and development	6,847	6,933
Selling, general and administrative	8,940	8,781
Total operating expenses	15,787	15,714
Operating income	1,364	9,819
Interest income	24	17
Interest expense	-79	-82
Income before income taxes	1,309	9,754
Income tax expense	1,002	1,812
Net income	$307	$7,942
Net income per share	'	'
Basic (in dollars per share)	$0.01	$0.32
Diluted (in dollars per share)	$0.01	$0.31
Weighted average number of common shares used to compute net income per share	'	'
Basic (in shares)	25,684	25,038
Diluted (in shares)	26,309	25,884

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Net income	$307	$7,942
Other comprehensive income, net of tax	'	'
Foreign currency translation adjustment	54	30
Total comprehensive income	$361	$7,972

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities	'	'
Net income	$307	$7,942
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	6,927	7,180
Amortization	103	143
Share-based compensation expense	1,209	1,441
Deferred income taxes, net	378	318
(Gain) loss on disposal of property and equipment	-74	51
Changes in working capital:	'	'
Accounts receivable	-2,651	9,472
Inventories	-83	-5,278
Other current and long-term assets	-541	2,784
Accounts payable	712	1,469
Income taxes payable	-451	455
Accrued and other liabilities	904	-2,367
Net cash provided by operating activities	6,740	23,610
Cash flows from investing activities	'	'
Purchases of property and equipment	-1,578	-10,243
Proceeds from sale of property and equipment	194	0
Restricted cash placed	-42	-3
Net cash used in investing activities	-1,426	-10,246
Cash flows from financing activities	'	'
Proceeds from exercise of stock options	23	376
Proceeds from borrowings	0	250
Repayments of borrowings	-1,429	-715
Principal payments on capital leases	-333	-250
Net cash used in financing activities	-1,739	-339
Effect of exchange rate changes on cash and cash equivalents	14	7
Net increase in cash and cash equivalents	3,589	13,032
Cash and cash equivalents at beginning of period	92,406	82,166
Cash and cash equivalents at end of period	95,995	95,198
Supplemental disclosures of non-cash investing information:	'	'
Property and equipment purchased but not yet paid	$2,157	$3,963

The_Company_and_Significant_Ac

The Company and Significant Accounting Policies	3 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
The Company and Significant Accounting Policies	'
	The Company and Significant Accounting Policies
	The Company
	Alpha and Omega Semiconductor Limited and its subsidiaries (the “Company”, "AOS", "we" or "us") design, develop and supply a broad range of power semiconductors. The Company's portfolio of products targets high-volume applications, including portable computers, flat panel TVs, LED lighting, smart phones, battery packs, consumer and industrial motor controls and power supplies for TVs, computers, servers and telecommunications equipment. The Company conducts its operations primarily in the United States of America (“USA”), Hong Kong, Macau, China, Taiwan, Korea and Japan.
	Basis of Preparation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2013. All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the period presented have been included in the interim period. Operating results for the three months ended September 30, 2013 are not necessarily indicative of the results that may be expected for other interim periods or the fiscal year ending June 30, 2014. The condensed consolidated balance sheet at June 30, 2013 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2013.
	Use of Estimates
	The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires the Company to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, the Company's condensed consolidated financial statements will be affected. On an ongoing basis, the Company evaluates the estimates, judgments and assumptions including those related to stock rotation returns, price adjustments, allowance for doubtful accounts, inventory reserves, warranty accrual, income taxes, share-based compensation, variable interest entities, and useful lives for property, plant and equipment and intangible assets.
	Fair Value of Financial Instruments
	The fair value of cash equivalents are based on observable market prices and have been categorized in Level 1 in the fair value hierarchy. Cash equivalents consist primarily of short term bank deposits. The carrying values of financial instruments such as cash and cash equivalents, accounts receivable and accounts payable approximate their carrying values due to their short-term maturities. The carrying value of the company's debt is considered a reasonable estimate of fair value which is estimated by considering the current rates available to the Company for debt of the same remaining maturities, structure and terms of the debts.
	Comprehensive Income
	Comprehensive income is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income consists of cumulative foreign currency translation adjustments. Total comprehensive income is presented in the condensed consolidated statements of comprehensive income.
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update ("ASU") 2013-11, Income Taxes (Topic 740) Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss ,or a Tax Credit Carryforward Exists. The new guidance requires the netting of unrecognized tax benefits ("UTBs") against a deferred tax asset for a loss or other carryforward that would apply in settlement of the uncertain tax positions. Under the new standard, UTBs will be netted against all available same-jurisdiction loss or other tax carryforwards that would be utilized, rather than only against carryforwards that are created by the UTBs. The ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. Early adoption is permitted. The ASU should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. The Company does not expect the adoption of this guidance to have any significant impact on the Company's condensed consolidated financial statements.

Net_Income_Per_Share

Net Income Per Share	3 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Net Income Per Share	'
	Net Income Per Share
	The following table presents the calculation of basic and diluted net income per share:
		Three Months Ended September 30,
		2013			2012
		(in thousands, except per share data)
	Numerator:
	Net income	$	307		$	7,942
	Denominator:
	Basic:
	Weighted average number of common shares used to compute basic net income per share	25,684			25,038
	Diluted:
	Weighted average number of common shares used to compute basic net income per share	25,684			25,038
	Effect of potentially dilutive securities:
	Stock options, RSUs and ESPP shares	625			846
	Weighted average number of common shares used to compute diluted net income per share	26,309			25,884
	Net income per share:
	Basic	$	0.01		$	0.32
	Diluted	$	0.01		$	0.31
	The following potential dilutive securities were excluded from the computation of diluted net income per share as their effect would have been anti-dilutive:
		Three Months Ended September 30,
		2013		2012
		(in thousands)
	Employee stock options and RSUs	2,783		2,694
	ESPP to purchase common shares	307		316
	Total potential dilutive securities	3,090		3,010

Concentration_of_Credit_Risk_a

Concentration of Credit Risk and Significant Customers	3 Months Ended
	Sep. 30, 2013
Risks and Uncertainties [Abstract]	'
Concentration of Credit Risk and Significant Customers	'
	Concentration of Credit Risk and Significant Customers
	The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers.
	Credit sales, which are mainly on credit terms of 30 to 60 days, are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its financial assets to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant bad debt write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available.
	Summarized below are individual customers whose revenue or accounts receivable balances were 10% or higher than the respective total consolidated amounts:
		Three Months Ended September 30,
	Percentage of revenue	2013		2012
	Customer A	20.6	%	23.6	%
	Customer B	44.3	%	41.5	%
	Customer C	11.8	%	13.7	%
		September 30,		June 30,
	Percentage of accounts receivable	2013		2013
	Customer A	20.5	%	33.8	%
	Customer B	37.8	%	22.6	%
	Customer C	17.9	%	19.9	%

Balance_Sheet_Components

Balance Sheet Components	3 Months Ended
	Sep. 30, 2013
Balance Sheet Related Disclosures [Abstract]	'
Balance Sheet Components	'
	Balance Sheet Components
	Accounts receivable:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Accounts receivable	$	54,545		$	52,202
	Less: Allowance for price adjustments	(13,566		)	(13,152		)
	Less: Allowance for doubtful accounts	(30		)	(752		)
	Accounts receivable, net	$	40,949		$	38,298
	Inventories:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Raw materials	$	20,224		$	17,248
	Work in-process	38,230			38,618
	Finished goods	9,968			12,473
		$	68,422		$	68,339
	Property, plant and equipment:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Land	$	4,950		$	4,950
	Building	4,106			4,106
	Manufacturing machinery and equipment	157,963			156,958
	Equipment and tooling	10,387			10,356
	Computer equipment and software	16,369			16,140
	Office furniture and equipment	1,566			1,559
	Leasehold improvements	24,224			24,068
		219,565			218,137
	Less accumulated depreciation	(94,121		)	(87,180		)
		125,444			130,957
	Equipment and construction in progress	7,534			7,154
	Property, plant and equipment, net	$	132,978		$	138,111
	Other long term assets:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Prepayments for property and equipment	$	265		$	77
	Investment in a privately held company	100			100
	Deferred debt issuance cost	67			91
	Office leases deposits	412			499
		$	844		$	767
	Accrued liabilities:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Accrued salaries and wages	$	2,979		$	3,079
	Accrued vacation	2,315			2,078
	Accrued bonuses	902			880
	Warranty accrual	1,361			1,428
	Stock rotation accrual	1,597			1,572
	Accrued professional fees	786			918
	ESPP payable	891			353
	Customer deposits	108			123
	Other accrued expenses	4,579			4,140
		$	15,518		$	14,571
	The activities in the warranty accrual, included in accrued liabilities, is as follows:
		Three Months Ended September 30,
		2013			2012
		(in thousands)
	Beginning balance	$	1,428		$	1,556
	Additions	285			118
	Utilization	(352		)	(113		)
Ending balance	$	1,361		$	1,561
The activities in the stock rotation accrual, included in accrued liabilities, is as follows:
	Three Months Ended September 30,
	2013			2012
	(in thousands)
Beginning balance	$	1,572		$	2,032
Additions	1,346			1,618
Utilization	(1,321		)	(1,872		)
Ending balance	$	1,597		$	1,778

Debt

Debt	3 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Debt	'
	Debt
	On May 11, 2012, the Company entered into a loan agreement with a financial institution that provides a term loan of $20.0 million for general purposes and a $10.0 million non-revolving credit line for the purchase of equipment. Both the term loan and equipment line will be fully repayable in May 2015. The borrowings may be made in the form of either Eurodollar loans or Base Rate loans. Eurodollar loans accrue interest based on an adjusted London Interbank Offered Rate ("LIBOR") as defined in the agreement, plus a margin of 1.00% to 1.75%. Base Rate loans accrue interest at the highest of (a) the lender's Prime Rate, (b) the Federal Funds Rate plus 0.5% and (c) the Eurodollar Rate (for a one-month interest period) plus 1%; plus a margin of -0.5% to 0.25%. The applicable margins for both Eurodollar loans and Base Rate loans will vary from time to time in the foregoing ranges based on the cash and cash equivalent balances maintained by the Company and its subsidiaries with the lender. In May 2013, the equipment credit line expired and there was no outstanding balance. As of September 30, 2013, the outstanding balance of the term loan was $15.7 million. Of the $15.7 million term loan, $2.9 million was included as short-term debt as of September 30, 2013.
	The obligations under the term loan are secured by substantially all assets of two subsidiaries of the Company, including, but not limited to, certain real property and related assets located at the Oregon fab. In addition, the Company and certain subsidiaries of the Company have agreed to guarantee full repayment and performance of the obligations under the loan agreement. The loan agreement contains customary restrictive covenants and includes certain financial covenants that require the Company to maintain on a consolidated basis specified financial ratios including total liabilities to tangible net worth, fixed charge coverage and current assets to current liabilities. As of September 30, 2013, the Company was in compliance with these covenants.
	Two of the Company's subsidiaries in China had revolving lines of credit that allow each of the subsidiaries to draw down, from time to time, up to 80% of the accounts receivable balance of such subsidiary, with an aggregated maximum amount of RMB 95 million (equivalent of $15.5 million based on the currency exchange rate as of September 30, 2013) to finance the subsidiary's working capital with a maximum of 120-day repayment term. The interest rate on each draw down varied and was indexed to the published LIBOR per annum. The Company did not renew these two lines of credit which expired in September 2013. As of September 30, 2013, there was no outstanding balance under these two revolving lines of credit.
	During July 2012, the Company entered into a loan agreement with the State of Oregon for an amount of $250,000. The loan is required to be used for training new and re-training existing employees of the Oregon Fab. The loan bears a compound annual interest rate of 5.0% and is to be repaid in April 2014. The State may forgive the loan and unpaid interest if certain conditions primarily relating to hiring targets are met and it is more likely than not that the Company will meet those hiring targets. As of September 30, 2013, the outstanding balance and accrued interest of the loan, included in short term debt, was $265,500.

Shareholders_Equity_and_Shareb

Shareholders' Equity and Share-based Compensation	3 Months Ended
	Sep. 30, 2013
Share-based Compensation [Abstract]	'
Shareholders' Equity and Share-based Compensation	'
	Shareholders' Equity and Share-based Compensation
	Share Repurchase
	On October 22, 2010, the Company's board of directors authorized a $25.0 million share repurchase program. Under this repurchase program the Company may, from time to time, repurchase shares from the open market or in privately negotiated transactions, subject to supervision and oversight by the board. The Company accounts for treasury stock under the cost method. Shares repurchased are accounted for as treasury shares and the total cost of shares repurchased is recorded as a reduction of shareholders' equity. From time to time, treasury shares may be reissued as part of the Company's stock-based compensation programs. Gains on re-issuance of treasury stock are credited to additional paid-in capital; losses are charged to additional paid-in capital to offset the net gains, if any, from previous sales or re-issuance of treasury stock. Any remaining balance of the losses are charged to retained earnings.
	During the three months ended September 30, 2013, the Company did not repurchase any shares under the program. During the three months ended September 30, 2013, the Company reissued 250 shares, with weighted average repurchase cost of $13.82 per share, upon vesting of certain restricted stock units ("RSU").
	As of September 30, 2013, the Company repurchased an aggregate of 241,770 shares for a total cost of $2.3 million, at an average repurchase price of $9.40 per share since inception of the program. Of the 241,770 repurchased shares, 16,050 shares with a weighted average repurchase price of $13.80 per share were reissued at an average price of $4.05 per share for option exercises and vested RSUs.
	Stock Options
	The following table summarizes the Company's stock option activities for the three months ended September 30, 2013:
				Weighted
				Average
		Number of		Exercise Price				Aggregate
		Shares		Per Share				Intrinsic Value
	Outstanding at June 30, 2013	3,593,854		$	10.24			$	3,144,506
	Granted	—		—
	Exercised	(27,750	)	0.83				195,606
	Canceled or forfeited	(1,025	)	4.66
	Outstanding at September 30, 2013	3,565,079		$	10.32			$	3,569,027
	Information with respect to stock options outstanding and exercisable at September 30, 2013 is as follows:
		Options Outstanding								Options Vested and Exercisable
		Number Outstanding		Weighted-Average		Weighted-Average				Number Exercisable		Weighted-Average
				Remaining Contractual Life (years)		Exercise Price						Exercise Price
	Total options outstanding	3,565,079		5.21		$	10.32			2,794,573		$	9.97
	Options vested and expected to vest	3,514,239		5.17		$	10.3
	Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options.
	Restricted Stock Units ("RSU")
	The following table summarizes the Company's RSU activities for the three months ended September 30, 2013:
		Number of Restricted Stock		Weighted Average				Weighted Average		Aggregate Intrinsic Value
		Units		Grant Date Fair				Remaining
				Value Per Share				Recognition
								Period (Years)
	Nonvested at June 30, 2013	549,553		$	9.5			1.87		$	4,198,585
	Granted	26,804		7.65
	Vested	(20,847	)	9.48
	Forfeited	(23,050	)	9.66
	Nonvested at September 30, 2013	532,460		$	9.4			1.69		$	4,477,989
	RSUs vested and expected to vest	481,109						1.62		$	4,046,123
	The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.
	Share-based Compensation Expense
	The total share-based compensation expense related to stock options, Employee Share Purchase Plan and RSUs described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows:
		Three Months Ended September 30,
		2013			2012
		(in thousands)
	Cost of goods sold	$	196		$	198
	Research and development	295			393
	Selling, general and administrative	718			850
		$	1,209		$	1,441
	Total unrecognized stock-based compensation expense as of September 30, 2013 was $4.5 million, which includes estimated forfeitures and is expected to be recognized over a weighted-average period of 1.3 years.

Income_Taxes

Income Taxes	3 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The Company recognized income tax expense of approximately $1.0 million and $1.8 million for the three months ended September 30, 2013 and 2012, respectively. The estimated effective tax rate was 76.5% and 18.6% for the three months ended September 30, 2013 and 2012, respectively. The effective tax rate for the three months ended September 30, 2013 was higher than that for same period of last year primarily due to the changes in the mix of earnings in various geographic jurisdictions between the two periods.
	The Company files its income tax returns in the United States and in various foreign jurisdictions. The tax years 2001 to 2013 remain open to examination by U.S. federal and state tax authorities. The tax years 2005 to 2013 remain open to examination by foreign tax authorities.
	The Company's income tax returns are subject to examinations by the Internal Revenue Service and other tax authorities in various jurisdictions. In accordance with the guidance on the accounting for uncertainty in income taxes, the Company regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of its provision for income taxes. These assessments can require considerable estimates and judgments. As of September 30, 2013, the gross amount of unrecognized tax benefits was approximately $7.6 million. If the Company's estimate of income tax liabilities proves to be less than the ultimate assessment, then a further charge to expense would be required. If events occur and the payment of these amounts ultimately proves to be unnecessary, the reversal of the liabilities would result in tax benefits being recognized in the period when the Company determines the liabilities are no longer necessary. The Company does not anticipate any material changes to its uncertain tax positions during the next twelve months.

Segment_and_Geographic_Informa

Segment and Geographic Information	3 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment and Geographic Information	'
	Segment and Geographic Information
	The Company is organized as, and operates in, one operating segment: the design, development and supply of power semiconductor products for computing, consumer electronics, communication and industrial applications. The chief operating decision-maker is the Chief Executive Officer. The financial information presented to the Company's Chief Executive Officer is on a consolidated basis, accompanied by information about revenue by customer and geographic region, for purposes of evaluating financial performance and allocating resources. The Company has one business segment, and there are no segment managers who are held accountable for operations, operating results and plans for products or components below the consolidated unit level. Accordingly, the Company reports as a single operating segment.
	The Company sells its products primarily to distributors in the Asia Pacific region, who in turn sell these products to end customers. Because the Company's distributors sell their products to end customers which may have a global presence, revenue by geographical location is not necessarily representative of the geographical distribution of sales to end user markets.
	The revenue by geographical location in the following tables is based on the country or region to which the products were shipped to:
		Three Months Ended September 30,
		2013		2012
		(in thousands)
	Hong Kong	$	71,256	$	74,627
	China	10,892		17,629
	South Korea	797		2,268
	United States	473		343
	Other countries	703		894
		$	84,121	$	95,761
	The following is a summary of revenue by product type:
		Three Months Ended September 30,
		2013		2012
		(in thousands)
	Power discrete	$	65,145	$	75,504
	Power IC	13,612		14,531
	Packaging and testing services	5,364		5,726
		$	84,121	$	95,761
	Long-lived assets, consisting of property, plant and equipment by geographical area are as follows:
		September 30,		June 30,
		2013		2013
		(in thousands)
	China	$	89,941	$	93,663
	United States	42,573		43,946
	Other countries	464		502
		$	132,978	$	138,111

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Purchase Commitments
	As of September 30, 2013 and June 30, 2013, the Company had approximately $18.9 million and $25.8 million, respectively, of outstanding purchase commitments primarily for purchases of semiconductor raw materials, wafers, spare parts and packaging and testing services; and approximately $1.9 million and $0.4 million, respectively, of capital commitments for the purchase of property and equipment.
	Contingencies and Indemnities
	The Company is currently not a party to any material legal proceedings. The Company has in the past, and may from time to time in the future, become involved in legal proceedings arising from the normal course of business activities. The semiconductor industry is characterized by frequent claims and litigation, including claims regarding patent and other intellectual property rights as well as improper hiring practices. Irrespective of the validity of such claims, the Company could incur significant costs in the defense thereof or could suffer adverse effects on its operations.
	The Company is a party to a variety of agreements that it has contracted with various third parties. Pursuant to these agreements, the Company may be obligated to indemnify another party to such an agreement with respect to certain matters. Typically, these obligations arise in the context of contracts entered into by the Company, under which the Company customarily agrees to hold the other party harmless against losses arising from a breach of representations and covenants related to such matters as title to assets sold, certain intellectual property rights, specified environmental matters and certain income taxes. In these circumstances, payment by the Company is customarily conditioned on the other party making a claim pursuant to the procedures specified in the particular contract, which procedures typically allow the Company to challenge the other party's claim. Further, the Company's obligations under these agreements may be limited in time and/or amount, and in some instances, the Company may have recourse against third parties for certain payments made by it under these agreements. The Company has not historically paid or recorded any material indemnifications and no accrual has been made at September 30, 2013 and June 30, 2013.
	The Company has agreed to indemnify its directors and certain employees as permitted by law and pursuant to its bye-laws, and has entered into indemnification agreements with its directors and executive officers. The Company has not recorded a liability associated with these indemnification arrangements, as it historically has not incurred any material costs associated with such indemnification obligations. Costs associated with such indemnification obligations may be mitigated by insurance coverage that the Company maintains, however, such insurance may not cover any, or may cover only a portion of, the amounts the Company may be required to pay. In addition, the Company may not be able to maintain such insurance coverage in the future.

The_Company_and_Significant_Ac1

The Company and Significant Accounting Policies (Policies)	3 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Concentration Risk, Credit Risk, Policy [Policy Text Block]	'
	The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers.
	Credit sales, which are mainly on credit terms of 30 to 60 days, are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its financial assets to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant bad debt write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available.
Basis of Preparation	'
	Basis of Preparation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2013. All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the period presented have been included in the interim period. Operating results for the three months ended September 30, 2013 are not necessarily indicative of the results that may be expected for other interim periods or the fiscal year ending June 30, 2014. The condensed consolidated balance sheet at June 30, 2013 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2013.
Use of Estimates	'
	Use of Estimates
	The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires the Company to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, the Company's condensed consolidated financial statements will be affected. On an ongoing basis, the Company evaluates the estimates, judgments and assumptions including those related to stock rotation returns, price adjustments, allowance for doubtful accounts, inventory reserves, warranty accrual, income taxes, share-based compensation, variable interest entities, and useful lives for property, plant and equipment and intangible assets.
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	The fair value of cash equivalents are based on observable market prices and have been categorized in Level 1 in the fair value hierarchy. Cash equivalents consist primarily of short term bank deposits. The carrying values of financial instruments such as cash and cash equivalents, accounts receivable and accounts payable approximate their carrying values due to their short-term maturities. The carrying value of the company's debt is considered a reasonable estimate of fair value which is estimated by considering the current rates available to the Company for debt of the same remaining maturities, structure and terms of the debts.
Comprehensive Income (Loss)	'
	Comprehensive Income
	Comprehensive income is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income consists of cumulative foreign currency translation adjustments. Total comprehensive income is presented in the condensed consolidated statements of comprehensive income.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update ("ASU") 2013-11, Income Taxes (Topic 740) Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss ,or a Tax Credit Carryforward Exists. The new guidance requires the netting of unrecognized tax benefits ("UTBs") against a deferred tax asset for a loss or other carryforward that would apply in settlement of the uncertain tax positions. Under the new standard, UTBs will be netted against all available same-jurisdiction loss or other tax carryforwards that would be utilized, rather than only against carryforwards that are created by the UTBs. The ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. Early adoption is permitted. The ASU should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. The Company does not expect the adoption of this guidance to have any significant impact on the Company's condensed consolidated financial statements.

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	3 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Schedule of Earnings Per Share, Basic and Diluted	'
	The following table presents the calculation of basic and diluted net income per share:
		Three Months Ended September 30,
		2013			2012
		(in thousands, except per share data)
	Numerator:
	Net income	$	307		$	7,942
	Denominator:
	Basic:
	Weighted average number of common shares used to compute basic net income per share	25,684			25,038
	Diluted:
	Weighted average number of common shares used to compute basic net income per share	25,684			25,038
	Effect of potentially dilutive securities:
	Stock options, RSUs and ESPP shares	625			846
	Weighted average number of common shares used to compute diluted net income per share	26,309			25,884
	Net income per share:
	Basic	$	0.01		$	0.32
	Diluted	$	0.01		$	0.31
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	'
	The following potential dilutive securities were excluded from the computation of diluted net income per share as their effect would have been anti-dilutive:
		Three Months Ended September 30,
		2013		2012
		(in thousands)
	Employee stock options and RSUs	2,783		2,694
	ESPP to purchase common shares	307		316
	Total potential dilutive securities	3,090		3,010

Concentration_of_Credit_Risk_a1

Concentration of Credit Risk and Significant Customers (Tables)	3 Months Ended
	Sep. 30, 2013
Risks and Uncertainties [Abstract]	'
Schedules of Concentration of Risk, by Risk Factor	'
	Summarized below are individual customers whose revenue or accounts receivable balances were 10% or higher than the respective total consolidated amounts:
		Three Months Ended September 30,
	Percentage of revenue	2013		2012
	Customer A	20.6	%	23.6	%
	Customer B	44.3	%	41.5	%
	Customer C	11.8	%	13.7	%
		September 30,		June 30,
	Percentage of accounts receivable	2013		2013
	Customer A	20.5	%	33.8	%
	Customer B	37.8	%	22.6	%
	Customer C	17.9	%	19.9	%

Balance_Sheet_Components_Table

Balance Sheet Components (Tables)	3 Months Ended
	Sep. 30, 2013
Balance Sheet Related Disclosures [Abstract]	'
Schedule of Accounts, Notes, Loans and Financing Receivable	'
	Accounts receivable:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Accounts receivable	$	54,545		$	52,202
	Less: Allowance for price adjustments	(13,566		)	(13,152		)
	Less: Allowance for doubtful accounts	(30		)	(752		)
	Accounts receivable, net	$	40,949		$	38,298
Schedule of Inventory, Current	'
	Inventories:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Raw materials	$	20,224		$	17,248
	Work in-process	38,230			38,618
	Finished goods	9,968			12,473
		$	68,422		$	68,339
Property, Plant and Equipment	'
	Property, plant and equipment:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Land	$	4,950		$	4,950
	Building	4,106			4,106
	Manufacturing machinery and equipment	157,963			156,958
	Equipment and tooling	10,387			10,356
	Computer equipment and software	16,369			16,140
	Office furniture and equipment	1,566			1,559
	Leasehold improvements	24,224			24,068
		219,565			218,137
	Less accumulated depreciation	(94,121		)	(87,180		)
		125,444			130,957
	Equipment and construction in progress	7,534			7,154
	Property, plant and equipment, net	$	132,978		$	138,111
Schedule of Other Assets, Noncurrent	'
	Other long term assets:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Prepayments for property and equipment	$	265		$	77
	Investment in a privately held company	100			100
	Deferred debt issuance cost	67			91
	Office leases deposits	412			499
		$	844		$	767
Schedule of Accrued Liabilities	'
	Accrued liabilities:
		September 30,			June 30,
		2013			2013
		(in thousands)
	Accrued salaries and wages	$	2,979		$	3,079
	Accrued vacation	2,315			2,078
	Accrued bonuses	902			880
	Warranty accrual	1,361			1,428
	Stock rotation accrual	1,597			1,572
	Accrued professional fees	786			918
	ESPP payable	891			353
	Customer deposits	108			123
	Other accrued expenses	4,579			4,140
		$	15,518		$	14,571
Schedule of Product Warranty Liability	'
	The activities in the warranty accrual, included in accrued liabilities, is as follows:
		Three Months Ended September 30,
		2013			2012
		(in thousands)
	Beginning balance	$	1,428		$	1,556
	Additions	285			118
	Utilization	(352		)	(113		)
	Ending balance	$	1,361		$	1,561
Stock Rotation Accrual	'
	The activities in the stock rotation accrual, included in accrued liabilities, is as follows:
		Three Months Ended September 30,
		2013			2012
		(in thousands)
	Beginning balance	$	1,572		$	2,032
	Additions	1,346			1,618
	Utilization	(1,321		)	(1,872		)
	Ending balance	$	1,597		$	1,778

Shareholders_Equity_and_Shareb1

Shareholders' Equity and Share-based Compensation (Tables)	3 Months Ended
	Sep. 30, 2013
Share-based Compensation [Abstract]	'
Summary of Stock Option Activites	'
	Stock Options
	The following table summarizes the Company's stock option activities for the three months ended September 30, 2013:
				Weighted
				Average
		Number of		Exercise Price				Aggregate
		Shares		Per Share				Intrinsic Value
	Outstanding at June 30, 2013	3,593,854		$	10.24			$	3,144,506
	Granted	—		—
	Exercised	(27,750	)	0.83				195,606
	Canceled or forfeited	(1,025	)	4.66
	Outstanding at September 30, 2013	3,565,079		$	10.32			$	3,569,027
	Information with respect to stock options outstanding and exercisable at September 30, 2013 is as follows:
		Options Outstanding								Options Vested and Exercisable
		Number Outstanding		Weighted-Average		Weighted-Average				Number Exercisable		Weighted-Average
				Remaining Contractual Life (years)		Exercise Price						Exercise Price
	Total options outstanding	3,565,079		5.21		$	10.32			2,794,573		$	9.97
	Options vested and expected to vest	3,514,239		5.17		$	10.3
	Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options.
Restricted Stock Units Activity	'
	Restricted Stock Units ("RSU")
	The following table summarizes the Company's RSU activities for the three months ended September 30, 2013:
		Number of Restricted Stock		Weighted Average				Weighted Average		Aggregate Intrinsic Value
		Units		Grant Date Fair				Remaining
				Value Per Share				Recognition
								Period (Years)
	Nonvested at June 30, 2013	549,553		$	9.5			1.87		$	4,198,585
	Granted	26,804		7.65
	Vested	(20,847	)	9.48
	Forfeited	(23,050	)	9.66
	Nonvested at September 30, 2013	532,460		$	9.4			1.69		$	4,477,989
	RSUs vested and expected to vest	481,109						1.62		$	4,046,123
	The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.
Share-based Compensation, Allocation of Recognized Period Costs	'
	Share-based Compensation Expense
	The total share-based compensation expense related to stock options, Employee Share Purchase Plan and RSUs described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows:
		Three Months Ended September 30,
		2013			2012
		(in thousands)
	Cost of goods sold	$	196		$	198
	Research and development	295			393
	Selling, general and administrative	718			850
		$	1,209		$	1,441

Segment_and_Geographic_Informa1

Segment and Geographic Information (Tables)	3 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	'
	Long-lived assets, consisting of property, plant and equipment by geographical area are as follows:
		September 30,		June 30,
		2013		2013
		(in thousands)
	China	$	89,941	$	93,663
	United States	42,573		43,946
	Other countries	464		502
		$	132,978	$	138,111
	The revenue by geographical location in the following tables is based on the country or region to which the products were shipped to:
		Three Months Ended September 30,
		2013		2012
		(in thousands)
	Hong Kong	$	71,256	$	74,627
	China	10,892		17,629
	South Korea	797		2,268
	United States	473		343
	Other countries	703		894
		$	84,121	$	95,761
Revenue from External Customers by Products and Services	'
	The following is a summary of revenue by product type:
		Three Months Ended September 30,
		2013		2012
		(in thousands)
	Power discrete	$	65,145	$	75,504
	Power IC	13,612		14,531
	Packaging and testing services	5,364		5,726
		$	84,121	$	95,761

Net_Income_Per_Share_Basic_and

Net Income Per Share - Basic and Diluted Income Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Numerator:	'	'
Net income	$307	$7,942
Basic:	'	'
Weighted average number of common shares used to compute basic net income per share	25,684	25,038
Effect of potentially dilutive securities:	'	'
Stock options, RSUs and ESPP shares (in shares)	625	846
Weighted average number of common shares used to compute diluted net income per share	26,309	25,884
Net income per share:	'	'
Basic (in dollars per share)	$0.01	$0.32
Diluted (in dollars per share)	$0.01	$0.31

Net_Income_Per_Share_Potential

Net Income Per Share - Potential Dilutive Shares (Details)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Potential dilutive securities (in shares)	3,090	3,010
Employee stock options and RSUs	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Potential dilutive securities (in shares)	2,783	2,694
ESPP to purchase common shares	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Potential dilutive securities (in shares)	307	316

Concentration_of_Credit_Risk_a2

Concentration of Credit Risk and Significant Customers - (Details)

3 Months Ended

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Jun. 30, 2013

Minimum

Maximum

Customer A

Customer A

Customer A

Customer A

Customer B

Customer B

Customer B

Customer B

Customer C

Customer C

Customer C

Customer C

Sales Revenue, Goods, Net

Sales Revenue, Goods, Net

Accounts Receivable

Accounts Receivable

Sales Revenue, Goods, Net

Sales Revenue, Goods, Net

Accounts Receivable

Accounts Receivable

Sales Revenue, Goods, Net

Sales Revenue, Goods, Net

Accounts Receivable

Accounts Receivable

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Concentration Risk

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Terms of credit sales, (in days)

'30 days

'60 days

'

'

'

'

'

'

'

'

'

'

'

'

Customers greater than 10% of total

'

'

20.60%

23.60%

20.50%

33.80%

44.30%

41.50%

37.80%

22.60%

11.80%

13.70%

17.90%

19.90%

Balance_Sheet_Components_Accou

Balance Sheet Components - Accounts receivable (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013
In Thousands, unless otherwise specified
Balance Sheet Related Disclosures [Abstract]	'	'
Accounts receivable	$54,545	$52,202
Less: allowance for price adjustments	-13,566	-13,152
Less: allowance for doubtful accounts	-30	-752
Accounts receivable, net	$40,949	$38,298

Balance_Sheet_Components_Inven

Balance Sheet Components - Inventories (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013
In Thousands, unless otherwise specified
Balance Sheet Related Disclosures [Abstract]	'	'
Raw materials	$20,224	$17,248
Work in-process	38,230	38,618
Finished goods	9,968	12,473
Inventory, net	$68,422	$68,339

Balance_Sheet_Components_Prope

Balance Sheet Components - Property, plant, and equipment (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	$219,565	$218,137
Less accumulated depreciation	-94,121	-87,180
Property, plant and equipment excluding equipment and construction in progress, net	125,444	130,957
Equipment and construction in progress	7,534	7,154
Property, plant and equipment, net	132,978	138,111
Land	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	4,950	4,950
Building	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	4,106	4,106
Manufacturing machinery and equipment	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	157,963	156,958
Equipment and tooling	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	10,387	10,356
Computer equipment and software	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	16,369	16,140
Office furniture and equipment	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	1,566	1,559
Leasehold improvements	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant, and equipment excluding equipment and construction In progress, gross	$24,224	$24,068

Balance_Sheet_Components_Other

Balance Sheet Components - Other long term assets (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013
In Thousands, unless otherwise specified
Balance Sheet Related Disclosures [Abstract]	'	'
Prepayments for property and equipment	$265	$77
Investment in a priveately held company	100	100
Deferred debt issuance cost	67	91
Office leases deposits	412	499
Other long-term assets	$844	$767

Balance_Sheet_Components_Accru

Balance Sheet Components - Accrued liabilites (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2012
In Thousands, unless otherwise specified
Balance Sheet Related Disclosures [Abstract]	'	'	'	'
Accrued salaries and wages	$2,979	$3,079	'	'
Accrued vacation	2,315	2,078	'	'
Accrued bonuses	902	880	'	'
Warranty accrual	1,361	1,428	1,561	1,556
Stock rotation accrual	1,597	1,572	1,778	2,032
Accrued professional fees	786	918	'	'
ESPP payable	891	353	'	'
Customer deposits	108	123	'	'
Other accrued expenses	4,579	4,140	'	'
Accrued liabilities	$15,518	$14,571	'	'

Balance_Sheet_Components_Produ

Balance Sheet Components - Product Warranty Accrual (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]	'	'
Beginning balance	$1,428	$1,556
Additions	285	118
Utilization	-352	-113
Ending balance	$1,361	$1,561

Balance_Sheet_Components_Stock

Balance Sheet Components - Stock Rotation Accrual (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Stock Rotation Accrual Increae (Decrease) [Roll Forward]	'	'
Beginning balance	$1,572	$2,032
Additions	1,346	1,618
Utilzation	-1,321	-1,872
Ending balance	$1,597	$1,778

Debt_Details

Debt - (Details)

3 Months Ended

3 Months Ended

3 Months Ended

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

11-May-12

Sep. 30, 2013

Jul. 17, 2012

Sep. 30, 2013

Sep. 30, 2013

USD ($)

CNY

Federal funds rate

Eurodollar rate

Minimum

Minimum

Maximum

Maximum

CHINA

Variable Interest Rate Term Loan Maturing May 2015

Variable Interest Rate Term Loan Maturing May 2015

State of Oregon Loan

State of Oregon Loan

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries

Subsidiaries

LIBOR rate

Margin Rate

LIBOR rate

Margin Rate

Subsidiaries

Notes Payable to Banks

Notes Payable to Banks

Loans Payable

Loans Payable

USD ($)

Maximum

USD ($)

USD ($)

USD ($)

USD ($)

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Amount Outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

$0

'

Loan, principal amount

'

'

'

'

'

'

'

'

'

'

20,000,000

'

250,000

'

'

Line of Credit Facility, Maximum Borrowing Capacity

15,500,000

95,000,000

'

'

'

'

'

'

'

'

10,000,000

'

'

'

'

Debt instrument, basis spread on variable rate

'

'

0.50%

1.00%

1.00%

-0.50%

1.75%

0.25%

'

'

'

'

'

'

'

Outstanding balance of loan

'

'

'

'

'

'

'

'

'

15,700,000

'

265,500

'

'

'

Outstanding balance of loan due in the next 12 months

'

'

'

'

'

'

'

'

'

$2,900,000

'

'

'

'

'

Number of subsidiaries securing obligations under loan agreement

2

2

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of subsidiaries with revolving lines of credit

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

Line of credit facility, subsidiaries, borrowing capacity, maximum percent of accounts receivable

'

'

'

'

'

'

'

'

'

'

'

'

'

'

80.00%

Repayment term of line of credit (in days)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'120 days

Interest rate on loan

'

'

'

'

'

'

'

'

'

'

'

'

5.00%

'

'

Shareholders_Equity_and_Shareb2

Shareholders' Equity and Share-based Compensation - Shares Repurchase (Details) (USD $)	0 Months Ended	29 Months Ended	35 Months Ended	3 Months Ended	35 Months Ended
In Millions, except Share data, unless otherwise specified	Oct. 22, 2010	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
				Treasury Stock Reissued	Treasury Stock Reissued
Class of Stock [Line Items]	'	'	'	'	'
Share repurchase program, authorized amount	$25	'	'	'	'
Treasury stock acquired, shares repurchased (in shares)	'	'	241,770	'	'
Treasury stock acquired, average price per share (in dollars per share)	'	$13.82	$9.40	'	$13.80
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	'	'	'	250	16,050
Treasury stock acquired	'	'	$2.30	'	'
Treasury stock reissued, average price per share (in dollars per share)	'	'	$4.05	'	'

Shareholders_Equity_and_Shareb3

Shareholders' Equity and Share-based Compensation - Share-based Compensation (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'
Outstanding at June 30, 2013 (in shares)	3,593,854	'
Granted (in shares)	0	'
Exercised (in shares)	-27,750	'
Canceled or forfeited (in shares)	-1,025	'
Outstanding at September 30, 2013 (in shares)	3,565,079	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]	'	'
Outstanding at June 30, 2013 (in dollars per share)	$10.24	'
Granted (in dollars per share)	$0	'
Exercised (in dollars per share)	$0.83	'
Canceled or forfeited (in dollars per share)	$4.66	'
Outstanding at September 30, 2013 (in dollars per share)	$10.32	'
Options Outstanding Aggregate Intrinsic Value	$3,569,027	$3,144,506
Options Exercised Aggegate Intrinsic Value	$195,606	'

Shareholders_Equity_and_Shareb4

Shareholders' Equity and Share-based Compensation - Stock Options Outstanding and Exercisable (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Jun. 30, 2013
Share-based Compensation [Abstract]	'	'
Options, Number Outstanding (in shares)	3,565,079	3,593,854
Options, Weighted-Average Remaining Contractual Life (in years)	'5 years 2 months 16 days	'
Options, Weighted-Average Exercise Price (in dollars per share)	$10.32	$10.24
Options, Number Exercisable (in shares)	2,794,573	'
Options, Weighted-Average Exercise Price (in dollars per share)	$9.97	'
Options vested and expected to vest, Number Outstanding (in shares)	3,514,239	'
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	'5 years 2 months 1 day	'
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share)	$10.30	'

Shareholders_Equity_and_Shareb5

Shareholders' Equity and Share-based Compensation - Restricted Stock Activity (Details) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'
Weighted Average Remaining Recognition Period (Years)	'1 year 3 months 18 days	'
Restricted Stock	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'	'
Nonvested	549,553	'
Granted	26,804	'
Vested	-20,847	'
Forfeited	-23,050	'
Nonvested	532,460	549,553
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'
Nonvested	$9.50	'
Granted	$7.65	'
Vested	$9.48	'
Forfeited	$9.66	'
Nonvested	$9.40	$9.50
Weighted Average Remaining Recognition Period (Years)	'1 year 8 months 9 days	'1 year 10 months 13 days
RSUs Nonvested Aggregate Intrinsic Value	$4,477,989	$4,198,585
RSUs vested and expected to vest, Outstanding (in shares)	481,109	'
RSUs vested and expected to vest, Weighted Average Remaining Recognition Period (in years)	'1 year 7 months 13 days	'
RSUs vested and expected to vest, Aggregate Intrinsic Value	$4,046,123	'

Shareholders_Equity_and_Shareb6

Shareholders' Equity and Share-based Compensation - Share-based Compensation Expenses (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Allocated share-based compensation expense	$1,209,000	$1,441,000
Unrecognized compensation expense	4,500,000	'
Recognition period of share-based compensation expense (in years)	'1 year 3 months 18 days	'
Cost of goods sold	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Allocated share-based compensation expense	196,000	198,000
Research and development	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Allocated share-based compensation expense	295,000	393,000
Selling, general and administrative	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Allocated share-based compensation expense	$718,000	$850,000

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'
Income tax expense	$1,002,000	$1,812,000
Estimated effective income tax rate	76.50%	18.60%
Unrecognized tax benefits	$7,600,000	'

Segment_and_Geographic_Informa2

Segment and Geographic Information - Revenue by Location and Product Type (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	$84,121	$95,761
Revenues from external customers	84,121	95,761
Power discrete	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues from external customers	65,145	75,504
Power IC	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues from external customers	13,612	14,531
Packaging and testing services	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues from external customers	5,364	5,726
Hong Kong	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	71,256	74,627
China	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	10,892	17,629
South Korea	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	797	2,268
United States	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	473	343
Other countries	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Revenues	$703	$894

Segment_and_Geographic_Informa3

Segment and Geographic Information - Long-lived Assets (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013
In Thousands, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Long-lived assets	$132,978	$138,111
China	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Long-lived assets	89,941	93,663
United States	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Long-lived assets	42,573	43,946
Other countries	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Long-lived assets	$464	$502

Segment_and_Geographic_Informa4

Segment and Geographic Information - Narratives (Details)	3 Months Ended
	Sep. 30, 2013
	Segment
Segment Reporting [Abstract]	'
Number of operating segments	1
Number of reportable segments	1

Commitments_and_Contingencies_

Commitments and Contingencies - Purchase Commitments (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013
In Millions, unless otherwise specified
Raw materials, wafers, and packaging and testing services puchase commitments	'	'
Purchase Commitment, Excluding Long-term Committment [Line Items]	'	'
Purchase commitment, amount	$18.90	$25.80
Property and equipment purchase commitments	'	'
Purchase Commitment, Excluding Long-term Committment [Line Items]	'	'
Purchase commitment, amount	$1.90	$0.40

Commitments_and_Contingencies_1

Commitments and Contingencies - Guarantees (Details) (Indemnification Agreement, USD $)	Sep. 30, 2013	Jun. 30, 2013
Indemnification Agreement	'	'
Loss Contingencies [Line Items]	'	'
Indemnifications accrual	$0	$0