Alpha and Omega Semiconductor Limited (AOSL) 10-Q 4 May 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Mar. 31, 2017	Apr. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	ALPHA & OMEGA SEMICONDUCTOR Ltd
Entity Central Index Key	1,387,467
Current Fiscal Year End Date	--06-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		23,790,333

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Current assets:
Cash and cash equivalents	$ 116,150	$ 87,774
Restricted cash	181	188
Accounts receivable, net	22,452	26,594
Inventories	73,349	68,848
Other current assets	4,948	4,526
Total current assets	217,080	187,930
Property, plant and equipment, net	117,335	116,084
Land use rights, net	8,737	0
Deferred income tax assets - long term	5,539	12,132
Other long term assets	21,522	2,359
Total assets	370,213	318,505
Current liabilities:
Accounts payable	44,990	42,718
Accrued liabilities	23,673	22,590
Income taxes payable	2,879	2,356
Deferred margin	713	997
Capital leases	820	819
Total current liabilities	73,075	69,480
Income taxes payable - long term	985	1,577
Deferred income tax liabilities	2,938	2,973
Capital leases - long term	1,071	1,695
Other long term liabilities	567	741
Total liabilities	78,636	76,466
Commitments and contingencies (Note 9)
Preferred shares, par value $0.002 per share:
Authorized: 10,000 shares, issued and outstanding: none at March 31, 2017 and June 30, 2016	0	0
Common shares, par value $0.002 per share:
Authorized: 50,000 shares, issued and outstanding: 29,391 shares and 23,778 shares, respectively at March 31, 2017 and 28,405 shares and 22,754 shares, respectively at June 30, 2016	59	57
Treasury shares at cost, 5,613 shares at March 31, 2017 and 5,651 shares at June 30, 2016	(49,876)	(50,199)
Additional paid-in capital	202,739	191,444
Accumulated other comprehensive income	39	769
Retained earnings	109,788	100,071
Total Alpha and Omega Semiconductor Limited shareholder's equity	262,749	242,142
Noncontrolling interest	28,828	(103)
Total equity	291,577	242,039
Total liabilities and equity	$ 370,213	$ 318,505

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2017	Jun. 30, 2016
Common shares, par value (in dollars per share)	$ 0.002	$ 0.002
Common shares, authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	29,391,000	28,405,000
Common stock, shares outstanding (in shares)	23,778,000	22,754,000
Preferred stock, par value (in dollars per share)	$ 0.002	$ 0.002
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)	5,613,000	5,651,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Revenue	$ 93,281	$ 82,987	$ 285,330	$ 244,251
Cost of goods sold	70,584	66,668	218,595	197,899
Gross profit	22,697	16,319	66,735	46,352
Operating expenses
Research and development	7,625	6,924	21,928	19,029
Selling, general and administrative	12,067	9,566	35,224	27,935
Impairment of long-lived assets	0	0	0	432
Total operating expenses	19,692	16,490	57,152	47,396
Operating income (loss)	3,005	(171)	9,583	(1,044)
Interest income and other income (loss), net	(74)	132	(193)	(335)
Interest expense	(22)	(5)	(72)	(22)
Net income (loss) before income taxes	2,909	(44)	9,318	(1,401)
Income tax expense	523	1,219	2,845	3,448
Net income (loss) including noncontrolling interest	2,386	(1,263)	6,473	(4,849)
Net loss attributable to noncontrolling interest	(1,170)	0	(3,237)	0
Net income (loss) attributable to Alpha and Omega Semiconductor Limited	$ 3,556	$ (1,263)	$ 9,710	$ (4,849)
Net income (loss) per common share attributable to Alpha and Omega Semiconductor Limited
Basic (in dollars per share)	$ 0.15	$ (0.06)	$ 0.42	$ (0.22)
Diluted (in dollars per share)	$ 0.14	$ (0.06)	$ 0.39	$ (0.22)
Weighted average number of common shares attributable to Alpha and Omega Semiconductor Limited used to compute net income (loss) per share
Basic (in shares)	23,675	22,232	23,396	22,400
Diluted (in shares)	24,951	22,232	24,781	22,400

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Net income (loss) including noncontrolling interest	$ 2,386	$ (1,263)	$ 6,473	$ (4,849)
Net income (loss) attributable to Alpha and Omega Semiconductor Limited	3,556	(1,263)	9,710	(4,849)
Foreign currency translation adjustment	693	22	(1,563)	(133)
Comprehensive income (loss)	3,079	(1,241)	4,910	(4,982)
Noncontrolling interest	(937)	0	(4,069)	0
Comprehensive income (loss) attributable to Alpha and Omega Semiconductor Limited	$ 4,016	$ (1,241)	$ 8,979	$ (4,982)

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities
Net income (loss) including noncontrolling interest	$ 6,473	$ (4,849)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	20,148	20,705
Share-based compensation expense	4,585	3,047
Deferred income taxes, net	6,558	791
Gain on disposal of property and equipment	(444)	0
Impairment of long-lived assets	0	432
Changes in assets and liabilities:
Accounts receivable, net	4,142	6,745
Inventories	(4,501)	(3,736)
Other current and long-term assets	(6,134)	(2,453)
Accounts payable	(1,711)	2,285
Income taxes payable	(68)	327
Accrued and other liabilities	52	3,067
Net cash provided by operating activities	29,100	26,361
Cash flows from investing activities
Purchases of property and equipment excluding JV Company	(16,163)	(13,777)
Purchases of property and equipment in JV Company	(15,857)	0
Purchases of land use rights in JV Company	(8,737)	0
Proceeds from sale of property and equipment	602	0
Decrease in restricted cash	7	22
Net cash used in investing activities	(40,148)	(13,755)
Cash flows from financing activities
Proceeds from investment by noncontrolling interest	33,000	0
Withholding tax on restricted stock units	(1,915)	(948)
Proceeds from exercise of stock options and ESPP	8,958	4,050
Payment for repurchases of common shares	0	(42,080)
Principal payments on capital leases	(622)	(706)
Net cash provided by (used in) financing activities	39,421	(39,684)
Effect of exchange rate changes on cash and cash equivalents	3	(84)
Net increase (decrease) in cash and cash equivalents	28,376	(27,162)
Cash and cash equivalents at beginning of period	87,774	106,085
Cash and cash equivalents at end of period	116,150	78,923
Supplemental disclosures of non-cash investing and financing information:
Property and equipment purchased but not yet paid	9,620	5,326
Re-issuance of treasury stock	$ 7	$ 164

The Company and Significant Acc

The Company and Significant Accounting Policies	9 Months Ended
	Mar. 31, 2017
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 personal 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, 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, 2016 . 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 periods presented have been included in the interim periods. Operating results for the nine months ended March 31, 2017 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2017 . The condensed consolidated balance sheet at June 30, 2016 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, 2016 . Reclassification The Company has reclassified certain amounts previously reported in its financial statements to conform to the current presentation. These reclassifications did not have a material impact on our consolidated financial statements. Joint Venture In March 2016, the Company executed an agreement with two strategic investment funds owned by the Municipality of Chongqing, China (the "Chongqing Funds") to form a joint venture for a new state-of-the-art power semiconductor packaging, testing and wafer fabrication facility in Liangjiang New Area of Chongqing (the "Joint Venture"). The initial capitalization of the Joint Venture under the agreement is $330.0 million , which includes cash contributions from the Chongqing Funds and contributions of cash, equipment and intangible assets from the Company. The Company owns 51% and the Chongqing Funds own 49% of the equity interest of the Joint Venture. The financial statements of the Joint Venture are consolidated in the accompanying financial statements of the Company because the Company has a controlling financial interest. 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, and useful lives for property, plant and equipment and intangible assets. Fair Value of Financial Instruments The fair values 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. Impairment of Long-Lived Assets Long-lived assets or asset groups are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Factors that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or any other significant adverse change that would indicate that the carrying amount of an asset or group of assets may not be recoverable. Where such factors indicate potential impairment, the recoverability of an asset or asset group is assessed by determining if the carrying value of the asset or asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life. The impairment loss is measured based on the difference between the carrying amount and the estimated fair value. Comprehensive Income (Loss) Comprehensive income (loss) 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 (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss). Recent Accounting Pronouncements In November 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-18, "Statement of Cash Flows: Restricted Cash ("ASU 2016-18"). ASU 2016-18 requires amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the total beginning and ending amounts for the periods shown on the statement of cash flows. This ASU will be effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted and requires retrospective adoption. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows. In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory ("ASU 2016-16"). ASU 2016-16 requires entities to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The amended guidance is effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-16 will have on its consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"). ASU 2016-15 identifies how certain cash receipts and cash payments are presented and classified in the Statement of Cash Flows under Topic 230. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted. Upon adoption, entities must apply the guidance retrospectively to all periods presented. The Company is currently evaluating the impact the adoption of ASU 2016-15 will have on its consolidated financial statements. In May 2016, the FASB issued Accounting Standards Update ("ASU") 2016-12, "Revenue from Contracts with Customers (Topic 606) - Narrow-Scope Improvements and Practical Expedients." ASU 2016-12 provides additional guidance established by the FASB-IASB Joint Transition Resource Group for Revenue Recognition regarding the implementation of certain aspects of the new revenue recognition guidance. More specifically, the amendment provides additional guidance regarding assessing the collectability criterion, the presentation of sales taxes and other similar taxes collected from customers, noncash consideration, contract modifications or completed contracts at transition of the new revenue recognition guidance and technical corrections. The effective date is consistent with the effective date of ASU 2014-09. The Company is currently evaluating the impact the adoption of ASU 2016-12 will have on its consolidated financial statements. In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10"). ASU 2016-10 clarifies two aspects of Topic 606: (a) identifying performance obligations; and (b) the licensing implementation guidance. The update is effective for annual periods beginning after December 15, 2017 including interim reporting periods therein. The Company is currently evaluating the impact the adoption of ASU 2016-10 will have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 simplifies several aspects of the accounting for employee share-based payment transactions including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. This guidance is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows. In February 2016, the FASB issued No. 2016-02, Leases ("ASU 2016-02"). This guidance requires a dual approach for lessee accounting under which a lessee will account for leases as finance leases or operating leases. Both finance and operating leases will result in the lessee recognizing a right-of-use asset and a corresponding liability on its balance sheet, with differing methodology for income statement recognition. This guidance is effective for public business entities for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. A modified retrospective approach is required for all leases existing or entered into after the beginning of the earliest comparative period in the consolidated financial statements. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. In August 2015, the FASB issued an accounting standard update for a one-year deferral of the effective date of ASU 2014-09 to annual and interim periods beginning after December 15, 2017 and permits entities to early adopt the standard of ASU 2014-09 for annual and interim reporting periods beginning after December 15, 2016. Companies are permitted to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Common Share Attributable to Alpha and Omega Semiconductor Limited The following table presents the calculation of basic and diluted net income (loss) per share attributable to common shareholders: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands, except per share data) Numerator: Net income (loss) attributable to Alpha and Omega Semiconductor Limited $ 3,556 $ (1,263 ) $ 9,710 $ (4,849 ) Denominator: Basic: Weighted average number of common shares used to compute basic net income (loss) per share 23,675 22,232 23,396 22,400 Diluted: Weighted average number of common shares used to compute basic net income (loss) per share 23,675 22,232 23,396 22,400 Effect of potentially dilutive securities: Stock options, RSUs and ESPP shares 1,276 — 1,385 — Weighted average number of common shares used to compute diluted net income (loss) per share 24,951 22,232 24,781 22,400 Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited: Basic $ 0.15 $ (0.06 ) $ 0.42 $ (0.22 ) Diluted $ 0.14 $ (0.06 ) $ 0.39 $ (0.22 ) The following potential dilutive securities were excluded from the computation of diluted net income (loss) per share as their effect would have been anti-dilutive: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Employee stock options and RSUs 3 3,003 83 3,307 ESPP 20 416 12 385 Total potential dilutive securities 23 3,419 95 3,692

Concentration of Credit Risk an

Concentration of Credit Risk and Significant Customers	9 Months Ended
	Mar. 31, 2017
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 and review 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 trade accounts receivable 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 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 more than 10% of the respective total consolidated amounts: Three Months Ended March 31, Nine Months Ended March 31, Percentage of revenue 2017 2016 2017 2016 Customer A 27.3 % 24.8 % 26.2 % 24.0 % Customer B 36.6 % 36.0 % 36.3 % 37.2 % Customer C 10.5 % 12.9 % 11.7 % 12.7 % March 31, June 30, Percentage of accounts receivable Customer A 28.5 % 21.3 % Customer B 10.1 % 16.7 % Customer C 27.0 % 27.2 %

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Mar. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Accounts receivable, net: March 31, June 30, (in thousands) Accounts receivable $ 41,163 $ 43,324 Less: Allowance for price adjustments (18,681 ) (16,700 ) Less: Allowance for doubtful accounts (30 ) (30 ) Accounts receivable, net $ 22,452 $ 26,594 Inventories: March 31, June 30, (in thousands) Raw materials $ 29,022 $ 23,982 Work in-process 35,699 32,446 Finished goods 8,628 12,420 $ 73,349 $ 68,848 Property, plant and equipment, net: March 31, June 30, (in thousands) Land $ 4,877 $ 4,877 Building 4,325 4,323 Manufacturing machinery and equipment 207,745 193,164 Equipment and tooling 13,364 12,289 Computer equipment and software 24,113 23,448 Office furniture and equipment 1,979 1,822 Leasehold improvements 29,043 28,660 285,446 268,583 Less: Accumulated depreciation (187,144 ) (168,687 ) 98,302 99,896 Equipment and construction in progress 19,033 16,188 Property, plant and equipment, net $ 117,335 $ 116,084 Land use rights, net: March 31, June 30, (in thousands) Land use rights $ 8,737 $ — Less: Accumulated depreciation — — Land use rights, net $ 8,737 $ — Other long-term assets: March 31, June 30, (in thousands) Prepayments for property and equipment $ 13,453 $ 506 Prepayment for others 216 42 Prepaid income tax 4,687 — Investment in a privately held company 100 100 Office leases deposits 527 388 Custom deposits 2,256 1,039 Intangible assets 14 15 Goodwill 269 269 $ 21,522 $ 2,359 Accrued liabilities: March 31, June 30, (in thousands) Accrued compensation and benefit $ 9,940 $ 10,211 Warranty accrual 1,872 1,495 Stock rotation accrual 1,712 1,988 Accrued professional fees 1,783 1,867 Accrued inventory 716 918 Accrued facilities related expenses 1,598 1,544 Other accrued expenses 6,052 4,567 $ 23,673 $ 22,590 The activities in the warranty accrual, included in accrued liabilities, are as follows: Nine Months Ended March 31, 2017 2016 (in thousands) Beginning balance $ 1,495 $ 1,957 Additions 898 803 Utilization (521 ) (1,164 ) Ending balance $ 1,872 $ 1,596 The activities in the stock rotation accrual, included in accrued liabilities, are as follows: Nine Months Ended March 31, 2017 2016 (in thousands) Beginning balance $ 1,988 $ 1,894 Additions 3,986 4,643 Utilization (4,262 ) (4,481 ) Ending balance $ 1,712 $ 2,056 Other Long-term liabilities: March 31, June 30, (in thousands) Deferred rent $ 567 $ 741

Joint Venture

Joint Venture	9 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Joint Venture	5. Joint Venture On March 29, 2016, the Company entered into a joint venture contract (the “JV Agreement”) with two investment funds owned by the Municipality of Chongqing (the “Chongqing Funds”), pursuant to which the Company and the Chongqing Funds formed a joint venture, (the “JV Company”), for the purpose of constructing and operating a power semiconductor packaging, testing and 12-inch wafer fabrication facility in the Liangjiang New Area of Chongqing, China (the “JV Transaction”). The total initial capitalization of the JV Company is $330.0 million (the “Initial Capitalization”), which includes cash contribution from the Chongqing Funds and contributions of cash, equipments and intangible assets from the Company. The Initial Capitalization is expected to be completed in stages. The Company owns 51% , and the Chongqing Funds own 49% , of the equity interest in the JV Company. If both parties agree that the termination of the JV Company is the best interest of each party or the JV Company is bankrupt or insolvent where either party may terminate early, after paying the debts of the JV Company, the remaining assets of the JV Company shall be paid to the Chongqing Funds to cover the principal of its total paid-in contributions plus interest at 10% simple annual rate prior to distributing the balance of the JV Company's assets to the Company. The Company expects the JV Company to commence its initial production in the second half of fiscal year ending June 30, 2018. There is no private land ownership in China. Individuals and companies are permitted to acquire land use rights for specific purpose. In September 2016, the JV Company paid approximately $8.7 million for land use rights to build the manufacturing facility. In March 2017, the JV Company received the necessary land use right certificate from the PRC government. The land use rights will expire on November 30, 2066. As part of the JV Transaction, the JV Company entered into an Engineering, Procurement and Construction Contract (the “EPC Contract”) with The IT Electronics Eleventh Design & Research Institute Scientific and Technological Engineering Corporation Limited (the “Contractor”), effective as of January 10, 2017 (the "Effective Date"), pursuant which the Contractor was engaged to construct the manufacturing facility contemplated under the JV Agreement. Under the EPC Contract, the Contractor’s obligations include, but are not limited to: (i) the development of conceptual design, initial design, construction drawing design and optimization, and submission of such designs to the JV Company for examination and confirmation; and (ii) the construction of the assembly and wafer fabrication facilities and related procurement services, including the selection and engagement of subcontractors, in accordance with a construction schedule agreed upon by the parties. The total price payable under the EPC Contract is Chinese Renminbi (RMB) 540,000,000 , or approximately $77,996,360 based on the currency exchange rate between RMB and U.S. Dollars on the Effective Date, which consists of $2,820,154 (RMB 19,525,052 ) of design fees (“Design Fees”) and $75,176,206 (RMB 520,474,948 ) of construction and procurement fees (including compliance with safety and aesthetic requirements) (“Construction Fees”). The Design Fees and Construction Fees will be paid by the JV Company pursuant to a payment schedule based on the progress of the construction and the achievements of specified milestones, approximately $58.3 million and $19.7 million in calendar year 2017 and 2018, respectively. The payment may be subject to volatility as a result of exposure to fluctuations in RMB foreign exchange rates. As of March 31, 2017, the JV Company paid approximately $11.9 million of down payment related to EPC Contract. The Company began consolidating the financial statements of the JV Company in the quarter ended June 30, 2016. During the quarter ended September 30, 2016, the Chongqing Funds contributed $33.0 million of initial capital in cash and the Company fulfilled its obligation to contribute certain packaging equipments as required by the JV Agreement by transferring the legal titles of such equipment to the JV Company. Within one year from June 30, 2016, the Company expects to contribute certain intangible assets and cash of $10.0 million pursuant to the terms of the JV Agreement. The changes in total stockholders' equity and noncontrolling interest were as follows (in thousands): Total AOS Stockholders' Equity Noncontrolling Interest Total Equity Balance, June 30, 2016 $ 242,142 $ (103 ) $ 242,039 Contributions from noncontrolling interest — 33,000 33,000 Exercise of common stock options and release of RSUs 7,462 — 7,462 Issuance of shares under ESPP 1,166 — 1,166 Reissuance of treasury stock upon exercise of common stock options and release of RSUs 330 — 330 Withholding tax on restricted stock units (1,915 ) — (1,915 ) Stock-based compensation expense 4,585 — 4,585 Net income (loss) 9,710 (3,237 ) 6,473 Cumulative translation adjustment (731 ) (832 ) (1,563 ) Balance, March 31, 2017 $ 262,749 $ 28,828 $ 291,577

Shareholders' Equity and Share-

Shareholders' Equity and Share-based Compensation	9 Months Ended
	Mar. 31, 2017
Share-based Compensation [Abstract]
Shareholders' Equity and Share-based Compensation	Shareholders' Equity and Share-based Compensation Share Repurchase In April 2015, the Board of Directors approved an increase in the remaining available amount under the Company’s then effective share repurchase program from approximately $17.8 million to $50.0 million . The repurchases may be made from the open market pursuant to a pre-established Rule 10b5-1 trading plan (as amended, the "Repurchase Trading Plan") or through privately negotiated transactions. In July 2015, the Company completed a Dutch tender offer (the "Tender Offer") in which it purchased 3,296,703 shares of its common shares, at a purchase price of $9.10 per share, for an aggregate purchase price of $30.0 million , excluding fees and expenses relating to the Tender Offer. The Tender Offer was part of the $50.0 million share repurchase program approved by the Board on April 15, 2015. Shares repurchased are accounted for as treasury shares and the total cost of shares repurchased is recorded as a reduction of shareholders' equity. During the nine months ended March 31, 2017 , the Company did not repurchase any shares pursuant to the repurchase program. Since the inception of the program in 2010, the Company repurchased an aggregate of 5,723,093 shares from the open market including shares purchased in the Tender Offer for a total cost of $50.8 million , at an average price of $8.87 per share, excluding fees and related expenses. No repurchased shares have been retired. Of the 5,723,093 repurchased shares, 110,153 shares with a weighted average repurchase price of $10.98 per share, were reissued at an average price of $5.79 per share pursuant to option exercises and vested restricted share units. As of March 31, 2017 , $6.4 million remained available under the share repurchase program. Stock Options The Company did not grant any stock options during the nine months ended March 31, 2017 . Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options. The following table summarizes the Company's stock option activities for the nine months ended March 31, 2017 : Weighted Weighted Average Average Remaining Number of Exercise Price Contractual Aggregate Shares Per Share Term (in years) Intrinsic Value Outstanding at June 30, 2016 1,859,260 $ 11.37 4.71 $ 5,959,720 Granted — $ — Exercised (657,469 ) $ 11.85 $ 5,382,647 Canceled or forfeited (112,500 ) $ 12.72 Outstanding at March 31, 2017 1,089,291 $ 10.95 4.63 $ 6,932,190 Options vested and expected to vest 1,082,604 $ 10.97 4.62 $ 6,868,038 Exercisable at March 31, 2017 948,874 $ 11.45 4.33 $ 5,580,467 Restricted Stock Units ("RSU") The following table summarizes the Company's RSU activities for the nine months ended March 31, 2017 : Number of Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Recognition Period (Years) Aggregate Intrinsic Value Nonvested at June 30, 2016 933,063 $ 9.18 1.73 $ 12,997,568 Granted 605,043 $ 18.10 Vested (328,226 ) $ 7.84 Forfeited (21,725 ) $ 12.38 Nonvested at March 31, 2017 1,188,155 $ 14.04 1.95 $ 20,424,384 RSUs vested and expected to vest 988,787 1.84 $ 16,997,248 The fair value of RSU is estimated based on the market price of the Company's share on the date of grant. In March 2017, the Company granted certain performance-based RSUs (“PRSUs”) to its key personnel. The number shares of PRSU were determined based on the level of attainment of predetermined financial goals. The PRSU will vest in four equal annual installments from March 15, 2018 if certain predetermined financial goals were met. The Company recorded approximately $68,000 of expenses for these PRSUs in the three and nine months ended March 31, 2017 based on 170,000 PRSU grants. Employee Share Purchase Plan ("ESPP") The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows: Nine Months Ended March 31, 2017 Volatility rate 39.09% Risk-free interest rate 0.6% - 1.0% Expected term 1.3 years Dividend yield 0% Share-based Compensation Expense T he total share-based compensation expense related to stock options, RSUs and ESPP described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Cost of goods sold $ 222 $ 187 $ 622 $ 475 Research and development 395 309 1,138 766 Selling, general and administrative 1,098 677 2,825 1,806 $ 1,715 $ 1,173 $ 4,585 $ 3,047 As of March 31, 2017 , total unrecognized compensation cost under the Company's equity plans was $10.8 million , which is expected to be recognized over a weighted-average period of 1.9 years.

Income Taxes

Income Taxes	9 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recognized income tax expense of approximately $0.5 million and $1.2 million for the three months ended March 31, 2017 and 2016 , respectively. The Company recognized income tax expense of approximately $2.8 million and $3.4 million for the nine months ended March 31, 2017 and 2016 , respectively. The estimated effective tax rate for the three months ended March 31, 2017 was 18.0% compared to (2,770.5)% for the three months ended March 31, 2016 . The estimated effective tax rate for the nine months ended March 31, 2017 was 30.5% compared to (246.1)% for the nine months ended March 31, 2016 . The changes in the effective tax rate and tax expense between the periods resulted primarily from changes in the mix of earnings in various geographic jurisdictions between the current quarter and the same period of last year. During the quarter ended September 30, 2016, the Company fulfilled its obligations to contribute certain packaging equipment as required by the JV Agreement by transferring the legal titles of such equipment to the JV Company. As a result of the transfer, the Company reduced its deferred tax assets by $6.6 million and recorded a $6.6 million in prepaid tax asset, which is amortized to tax expense over the useful life of the assets. As of March 31, 2017 , the prepaid tax asset was amortized down to $5.8 million , of which $1.1 million and $4.7 million were included in prepaid and other current assets and other long-term assets on the Company’s balance sheet, respectively. The Company files its income tax returns in the United States and in various foreign jurisdictions. The tax years 2001 to 2016 remain open to examination by U.S. federal and state tax authorities. The tax years 2009 to 2016 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 March 31, 2017 , the gross amount of unrecognized tax benefits was approximately $6.4 million , of which $4.0 million , if recognized, would reduce the effective income tax rate in future periods. 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 . On July 27, 2015, in Altera Corp. v. Commissioner , the U.S. Tax Court issued an opinion related to the treatment of share-based compensation expense in an intercompany cost-sharing arrangement. A final decision has yet to be issued by the Tax Court due to other outstanding issues related to the case. At this time, the U.S. Department of the Treasury has not withdrawn the requirement to include share-based compensation from its regulations. Due to the uncertainty surrounding the status of the current regulations, questions related to the scope of potential benefits, and the risk of the Tax Court’s decision being overturned upon appeal, the Company has not recorded any benefit as of March 31, 2017 . The Company will continue to monitor ongoing developments and potential impacts to its financial statements.

Segment and Geographic Informat

Segment and Geographic Information	9 Months Ended
	Mar. 31, 2017
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 March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Hong Kong $ 75,785 $ 71,684 $ 236,873 $ 212,041 China 15,334 9,520 42,159 26,458 South Korea 294 504 1,053 1,604 United States 1,075 726 2,767 2,227 Other Countries 793 553 2,478 1,921 $ 93,281 $ 82,987 $ 285,330 $ 244,251 The following is a summary of revenue by product type: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Power discrete $ 70,794 $ 63,464 $ 212,044 $ 182,769 Power IC 19,309 16,251 64,166 50,164 Packaging and testing services 3,178 3,272 9,120 11,318 $ 93,281 $ 82,987 $ 285,330 $ 244,251 Long-lived assets, net consisting of property, plant and equipment and land use rights, by geographical area are as follows: March 31, June 30, (in thousands) China $ 68,528 $ 64,272 United States 56,875 51,214 Other Countries 669 598 $ 126,072 $ 116,084

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Commitments As of March 31, 2017 and June 30, 2016 , the Company had approximately $31.2 million and $39.6 million , respectively, of outstanding purchase commitments primarily for purchases of semiconductor raw materials, wafers, spare parts and packaging and testing services, and approximately $11.1 million and $6.6 million , respectively, of capital commitments for the purchase of property and equipment. Contingencies and Indemnities The Company is currently not a party to any pending 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 of such claims and 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 March 31, 2017 and June 30, 2016 . 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. Joint Venture In March 2016, the Company executed an agreement with two strategic investment funds owned by the Municipality of Chongqing, China to form a joint venture for a new state-of-the-art power semiconductor packaging, testing and wafer fabrication facility in Liangjiang New Area of Chongqing (the "Joint Venture"). The initial capitalization of the Joint Venture under the agreement is $330.0 million , which includes cash contribution from the Chongqing Funds and contributions of cash, equipment and intangible assets from the Company. The Company owns 51% and the Chongqing Funds own 49% of the equity interest of the Joint Venture. The Joint Venture is accounted under the provisions of the consolidation guidance since the Company has controlling financial interest. The Joint Venture is expected to commence its initial packaging production in the second half of fiscal year ending June 30, 2018. Within one year from June 30, 2016, the Company is expected to contribute cash of $10.0 million and certain intangible assets. The Joint Venture plans to construct and operate a 12-inch wafer fabrication facility for the production of power semiconductors. In January 2017, the JV Company entered into an Engineering, Procurement and Construction Contract (the "EPC Contract") with The IT Electronics Eleventh Design & Research Institute Scientific and Technological Engineering Corporation Limited, effective as of January 10, 2017 (the "Effective Date"). The total price payable by the JV Company under the EPC Contract is RMB 540,000,000 , or $77,996,360 based on the currency exchange rate between RMB and U.S. Dollars on the Effective Date, which consists of $2,820,154 (RMB 19,525,052 ) of design fees and $ 75,176,206 (RMB 520,474,948 ) of construction and procurement fees, including compliance with safety and aesthetic requirements.

The Company and Significant A16

The Company and Significant Accounting Policies (Policies)	9 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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, 2016 . 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 periods presented have been included in the interim periods. Operating results for the nine months ended March 31, 2017 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2017 . The condensed consolidated balance sheet at June 30, 2016 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, 2016 .
Reclassification	Reclassification The Company has reclassified certain amounts previously reported in its financial statements to conform to the current presentation. These reclassifications did not have a material impact on our consolidated financial statements.
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, and useful lives for property, plant and equipment and intangible assets.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The fair values 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.
Impairment of Long-Lived Assets [Policy Text Block]	Impairment of Long-Lived Assets Long-lived assets or asset groups are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Factors that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or any other significant adverse change that would indicate that the carrying amount of an asset or group of assets may not be recoverable. Where such factors indicate potential impairment, the recoverability of an asset or asset group is assessed by determining if the carrying value of the asset or asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life. The impairment loss is measured based on the difference between the carrying amount and the estimated fair value.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) 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 (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss).
Recent Accounting Pronouncements	Recent Accounting Pronouncements In November 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-18, "Statement of Cash Flows: Restricted Cash ("ASU 2016-18"). ASU 2016-18 requires amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the total beginning and ending amounts for the periods shown on the statement of cash flows. This ASU will be effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted and requires retrospective adoption. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows. In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory ("ASU 2016-16"). ASU 2016-16 requires entities to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The amended guidance is effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-16 will have on its consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"). ASU 2016-15 identifies how certain cash receipts and cash payments are presented and classified in the Statement of Cash Flows under Topic 230. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted. Upon adoption, entities must apply the guidance retrospectively to all periods presented. The Company is currently evaluating the impact the adoption of ASU 2016-15 will have on its consolidated financial statements. In May 2016, the FASB issued Accounting Standards Update ("ASU") 2016-12, "Revenue from Contracts with Customers (Topic 606) - Narrow-Scope Improvements and Practical Expedients." ASU 2016-12 provides additional guidance established by the FASB-IASB Joint Transition Resource Group for Revenue Recognition regarding the implementation of certain aspects of the new revenue recognition guidance. More specifically, the amendment provides additional guidance regarding assessing the collectability criterion, the presentation of sales taxes and other similar taxes collected from customers, noncash consideration, contract modifications or completed contracts at transition of the new revenue recognition guidance and technical corrections. The effective date is consistent with the effective date of ASU 2014-09. The Company is currently evaluating the impact the adoption of ASU 2016-12 will have on its consolidated financial statements. In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10"). ASU 2016-10 clarifies two aspects of Topic 606: (a) identifying performance obligations; and (b) the licensing implementation guidance. The update is effective for annual periods beginning after December 15, 2017 including interim reporting periods therein. The Company is currently evaluating the impact the adoption of ASU 2016-10 will have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 simplifies several aspects of the accounting for employee share-based payment transactions including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. This guidance is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows. In February 2016, the FASB issued No. 2016-02, Leases ("ASU 2016-02"). This guidance requires a dual approach for lessee accounting under which a lessee will account for leases as finance leases or operating leases. Both finance and operating leases will result in the lessee recognizing a right-of-use asset and a corresponding liability on its balance sheet, with differing methodology for income statement recognition. This guidance is effective for public business entities for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. A modified retrospective approach is required for all leases existing or entered into after the beginning of the earliest comparative period in the consolidated financial statements. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. In August 2015, the FASB issued an accounting standard update for a one-year deferral of the effective date of ASU 2014-09 to annual and interim periods beginning after December 15, 2017 and permits entities to early adopt the standard of ASU 2014-09 for annual and interim reporting periods beginning after December 15, 2016. Companies are permitted to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements.
Concentration of Credit Risk	The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application and review 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 trade accounts receivable 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 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.

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the calculation of basic and diluted net income (loss) per share attributable to common shareholders: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands, except per share data) Numerator: Net income (loss) attributable to Alpha and Omega Semiconductor Limited $ 3,556 $ (1,263 ) $ 9,710 $ (4,849 ) Denominator: Basic: Weighted average number of common shares used to compute basic net income (loss) per share 23,675 22,232 23,396 22,400 Diluted: Weighted average number of common shares used to compute basic net income (loss) per share 23,675 22,232 23,396 22,400 Effect of potentially dilutive securities: Stock options, RSUs and ESPP shares 1,276 — 1,385 — Weighted average number of common shares used to compute diluted net income (loss) per share 24,951 22,232 24,781 22,400 Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited: Basic $ 0.15 $ (0.06 ) $ 0.42 $ (0.22 ) Diluted $ 0.14 $ (0.06 ) $ 0.39 $ (0.22 )
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 (loss) per share as their effect would have been anti-dilutive: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Employee stock options and RSUs 3 3,003 83 3,307 ESPP 20 416 12 385 Total potential dilutive securities 23 3,419 95 3,692

Concentration of Credit Risk 18

Concentration of Credit Risk and Significant Customers (Tables)	9 Months Ended
	Mar. 31, 2017
Risks and Uncertainties [Abstract]
Schedules of Concentration of Risk, by Risk Factor	Summarized below are individual customers whose revenue or accounts receivable balances were more than 10% of the respective total consolidated amounts: Three Months Ended March 31, Nine Months Ended March 31, Percentage of revenue 2017 2016 2017 2016 Customer A 27.3 % 24.8 % 26.2 % 24.0 % Customer B 36.6 % 36.0 % 36.3 % 37.2 % Customer C 10.5 % 12.9 % 11.7 % 12.7 % March 31, June 30, Percentage of accounts receivable Customer A 28.5 % 21.3 % Customer B 10.1 % 16.7 % Customer C 27.0 % 27.2 %

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Mar. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	Accounts receivable, net: March 31, June 30, (in thousands) Accounts receivable $ 41,163 $ 43,324 Less: Allowance for price adjustments (18,681 ) (16,700 ) Less: Allowance for doubtful accounts (30 ) (30 ) Accounts receivable, net $ 22,452 $ 26,594
Schedule of Inventory, Current	Inventories: March 31, June 30, (in thousands) Raw materials $ 29,022 $ 23,982 Work in-process 35,699 32,446 Finished goods 8,628 12,420 $ 73,349 $ 68,848
Property, Plant and Equipment	Property, plant and equipment, net: March 31, June 30, (in thousands) Land $ 4,877 $ 4,877 Building 4,325 4,323 Manufacturing machinery and equipment 207,745 193,164 Equipment and tooling 13,364 12,289 Computer equipment and software 24,113 23,448 Office furniture and equipment 1,979 1,822 Leasehold improvements 29,043 28,660 285,446 268,583 Less: Accumulated depreciation (187,144 ) (168,687 ) 98,302 99,896 Equipment and construction in progress 19,033 16,188 Property, plant and equipment, net $ 117,335 $ 116,084
Summary of Land Use Rights, Net	Land use rights, net: March 31, June 30, (in thousands) Land use rights $ 8,737 $ — Less: Accumulated depreciation — — Land use rights, net $ 8,737 $ —
Schedule of Other Assets, Noncurrent	Other long-term assets: March 31, June 30, (in thousands) Prepayments for property and equipment $ 13,453 $ 506 Prepayment for others 216 42 Prepaid income tax 4,687 — Investment in a privately held company 100 100 Office leases deposits 527 388 Custom deposits 2,256 1,039 Intangible assets 14 15 Goodwill 269 269 $ 21,522 $ 2,359
Schedule of Accrued Liabilities	Accrued liabilities: March 31, June 30, (in thousands) Accrued compensation and benefit $ 9,940 $ 10,211 Warranty accrual 1,872 1,495 Stock rotation accrual 1,712 1,988 Accrued professional fees 1,783 1,867 Accrued inventory 716 918 Accrued facilities related expenses 1,598 1,544 Other accrued expenses 6,052 4,567 $ 23,673 $ 22,590
Schedule of Product Warranty Liability	The activities in the warranty accrual, included in accrued liabilities, are as follows: Nine Months Ended March 31, 2017 2016 (in thousands) Beginning balance $ 1,495 $ 1,957 Additions 898 803 Utilization (521 ) (1,164 ) Ending balance $ 1,872 $ 1,596
Stock Rotation Accrual	The activities in the stock rotation accrual, included in accrued liabilities, are as follows: Nine Months Ended March 31, 2017 2016 (in thousands) Beginning balance $ 1,988 $ 1,894 Additions 3,986 4,643 Utilization (4,262 ) (4,481 ) Ending balance $ 1,712 $ 2,056
Schedule of Other Noncurrent Liabilities	Other Long-term liabilities: March 31, June 30, (in thousands) Deferred rent $ 567 $ 741

Joint Venture (Tables)

Joint Venture (Tables)	9 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Stockholders Equity	The changes in total stockholders' equity and noncontrolling interest were as follows (in thousands): Total AOS Stockholders' Equity Noncontrolling Interest Total Equity Balance, June 30, 2016 $ 242,142 $ (103 ) $ 242,039 Contributions from noncontrolling interest — 33,000 33,000 Exercise of common stock options and release of RSUs 7,462 — 7,462 Issuance of shares under ESPP 1,166 — 1,166 Reissuance of treasury stock upon exercise of common stock options and release of RSUs 330 — 330 Withholding tax on restricted stock units (1,915 ) — (1,915 ) Stock-based compensation expense 4,585 — 4,585 Net income (loss) 9,710 (3,237 ) 6,473 Cumulative translation adjustment (731 ) (832 ) (1,563 ) Balance, March 31, 2017 $ 262,749 $ 28,828 $ 291,577

Shareholders' Equity and Shar21

Shareholders' Equity and Share-based Compensation (Tables)	9 Months Ended
	Mar. 31, 2017
Share-based Compensation [Abstract]
Summary of Stock Option Activities	Stock Options The Company did not grant any stock options during the nine months ended March 31, 2017 . Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options. The following table summarizes the Company's stock option activities for the nine months ended March 31, 2017 : Weighted Weighted Average Average Remaining Number of Exercise Price Contractual Aggregate Shares Per Share Term (in years) Intrinsic Value Outstanding at June 30, 2016 1,859,260 $ 11.37 4.71 $ 5,959,720 Granted — $ — Exercised (657,469 ) $ 11.85 $ 5,382,647 Canceled or forfeited (112,500 ) $ 12.72 Outstanding at March 31, 2017 1,089,291 $ 10.95 4.63 $ 6,932,190 Options vested and expected to vest 1,082,604 $ 10.97 4.62 $ 6,868,038 Exercisable at March 31, 2017 948,874 $ 11.45 4.33 $ 5,580,467
Restricted Stock Units Activity	Restricted Stock Units ("RSU") The following table summarizes the Company's RSU activities for the nine months ended March 31, 2017 : Number of Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Recognition Period (Years) Aggregate Intrinsic Value Nonvested at June 30, 2016 933,063 $ 9.18 1.73 $ 12,997,568 Granted 605,043 $ 18.10 Vested (328,226 ) $ 7.84 Forfeited (21,725 ) $ 12.38 Nonvested at March 31, 2017 1,188,155 $ 14.04 1.95 $ 20,424,384 RSUs vested and expected to vest 988,787 1.84 $ 16,997,248 The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	Employee Share Purchase Plan ("ESPP") The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows: Nine Months Ended March 31, 2017 Volatility rate 39.09% Risk-free interest rate 0.6% - 1.0% Expected term 1.3 years Dividend yield 0%
Share-based Compensation, Allocation of Recognized Period Costs	Share-based Compensation Expense T he total share-based compensation expense related to stock options, RSUs and ESPP described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Cost of goods sold $ 222 $ 187 $ 622 $ 475 Research and development 395 309 1,138 766 Selling, general and administrative 1,098 677 2,825 1,806 $ 1,715 $ 1,173 $ 4,585 $ 3,047

Segment and Geographic Inform22

Segment and Geographic Information (Tables)	9 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	Long-lived assets, net consisting of property, plant and equipment and land use rights, by geographical area are as follows: March 31, June 30, (in thousands) China $ 68,528 $ 64,272 United States 56,875 51,214 Other Countries 669 598 $ 126,072 $ 116,084 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 March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Hong Kong $ 75,785 $ 71,684 $ 236,873 $ 212,041 China 15,334 9,520 42,159 26,458 South Korea 294 504 1,053 1,604 United States 1,075 726 2,767 2,227 Other Countries 793 553 2,478 1,921 $ 93,281 $ 82,987 $ 285,330 $ 244,251
Revenue from External Customers by Products and Services	The following is a summary of revenue by product type: Three Months Ended March 31, Nine Months Ended March 31, 2017 2016 2017 2016 (in thousands) (in thousands) Power discrete $ 70,794 $ 63,464 $ 212,044 $ 182,769 Power IC 19,309 16,251 64,166 50,164 Packaging and testing services 3,178 3,272 9,120 11,318 $ 93,281 $ 82,987 $ 285,330 $ 244,251

The Company and Significant A23

The Company and Significant Accounting Policies Joint Venture (Details) - Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member] - USD ($) $ in Millions	1 Months Ended
	Mar. 31, 2016	Mar. 29, 2016
Corporate Joint Venture [Member]
Initial capitalization of joint venture		$ 330
Chongqing Funds [Member]
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	49.00%
Parent Company [Member]
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	51.00%

Net Income (Loss) Per Share - B

Net Income (Loss) Per Share - Basic and Diluted Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net income (loss) attributable to Alpha and Omega Semiconductor Limited	$ 3,556	$ (1,263)	$ 9,710	$ (4,849)
Basic:
Weighted average number of common shares used to compute basic net income (loss) per share	23,675	22,232	23,396	22,400
Effect of potentially dilutive securities:
Stock options, RSUs and ESPP shares	1,276	0	1,385	0
Weighted average number of common shares used to compute diluted net income (loss) per share	24,951	22,232	24,781	22,400
Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited:
Basic (in dollars per share)	$ 0.15	$ (0.06)	$ 0.42	$ (0.22)
Diluted (in dollars per share)	$ 0.14	$ (0.06)	$ 0.39	$ (0.22)

Net Income (Loss) Per Share - P

Net Income (Loss) Per Share - Potential Dilutive Shares (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	23	3,419	95	3,692
Employee stock options and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	3	3,003	83	3,307
ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	20	416	12	385

Concentration of Credit Risk 26

Concentration of Credit Risk and Significant Customers - (Details)	3 Months Ended			9 Months Ended
	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Minimum [Member]
Concentration Risk
Terms of credit sales, (in days)				30 days
Maximum [Member]
Concentration Risk
Terms of credit sales, (in days)				60 days
Customer A | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	27.30%		24.80%	26.20%	24.00%
Customer A | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	28.50%	21.30%
Customer B | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	36.60%		36.00%	36.30%	37.20%
Customer B | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	10.10%	16.70%
Customer C | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	10.50%		12.90%	11.70%	12.70%
Customer C | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	27.00%	27.20%

Balance Sheet Components - Acco

Balance Sheet Components - Accounts receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Accounts receivable	$ 41,163	$ 43,324
Less: Allowance for price adjustments	(18,681)	(16,700)
Less: Allowance for doubtful accounts	(30)	(30)
Accounts receivable, net	$ 22,452	$ 26,594

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 29,022	$ 23,982
Work in-process	35,699	32,446
Finished goods	8,628	12,420
Inventory, net	$ 73,349	$ 68,848

Balance Sheet Components - Prop

Balance Sheet Components - Property, plant, and equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 285,446	$ 268,583
Less: Accumulated depreciation	(187,144)	(168,687)
Property, plant and equipment excluding equipment and construction in progress, net	98,302	99,896
Equipment and construction in progress	19,033	16,188
Property, plant and equipment, net	117,335	116,084
Land
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	4,877	4,877
Building
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	4,325	4,323
Manufacturing machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	207,745	193,164
Equipment and tooling
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	13,364	12,289
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	24,113	23,448
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	1,979	1,822
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 29,043	$ 28,660

Balance Sheet Components - Land

Balance Sheet Components - Land Use Rights, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Land use rights	$ 8,737	$ 0
Less: Accumulated depreciation	0	0
Land use rights, net	$ 8,737	$ 0

Balance Sheet Components - Othe

Balance Sheet Components - Other long term assets (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Prepayments for property and equipment	$ 13,453	$ 506
Prepayment for others	216	42
Prepaid income tax	4,687	0
Investment in a privately held company	100	100
Office leases deposits	527	388
Custom deposits	2,256	1,039
Intangible assets	14	15
Goodwill	269	269
Other long-term assets	$ 21,522	$ 2,359

Balance Sheet Components - Accr

Balance Sheet Components - Accrued liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Accrued compensation and benefit	$ 9,940	$ 10,211
Warranty accrual	1,872	1,495	$ 1,596	$ 1,957
Stock rotation accrual	1,712	1,988	$ 2,056	$ 1,894
Accrued professional fees	1,783	1,867
Accrued inventory	716	918
Accrued facilities related expenses	1,598	1,544
Other accrued expenses	6,052	4,567
Accrued liabilities	$ 23,673	$ 22,590

Balance Sheet Components - Prod

Balance Sheet Components - Product Warranty Accrual (Details) - USD ($) $ in Thousands	9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Beginning balance	$ 1,495	$ 1,957
Additions	898	803
Utilization	(521)	(1,164)
Ending balance	$ 1,872	$ 1,596

Balance Sheet Components - Stoc

Balance Sheet Components - Stock Rotation Accrual (Details) - USD ($) $ in Thousands	9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Stock Rotation Accrual Increae (Decrease) [Roll Forward]
Beginning balance	$ 1,988	$ 1,894
Additions	3,986	4,643
Utilization	(4,262)	(4,481)
Ending balance	$ 1,712	$ 2,056

Balance Sheet Components - Ot35

Balance Sheet Components - Other Long Term Liability (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Deferred rent	$ 567	$ 741
Other long term liabilities	$ 567	$ 741

Joint Venture - Narrative (Deta

Joint Venture - Narrative (Details)	1 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2016USD ($)	Mar. 31, 2016	Sep. 30, 2016USD ($)	Mar. 31, 2017USD ($)	Mar. 31, 2016USD ($)	Jan. 10, 2017CNY (¥)	Jan. 10, 2017USD ($)	Mar. 29, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Purchases of land use rights in JV Company				$ 8,737,000	$ 0
Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Schedule of Equity Method Investments [Line Items]
Interest rate to concontrolling interest if joint venture is early terminated and liquidated		10.00%
Corporate Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Total price payable under EPC Contract						¥ 540,000,000	$ 77,996,360
Contract amount payable in 2017							58,300,000
Contract amount payable in 2018							19,700,000
Contract down payment				$ 11,900,000
Corporate Joint Venture [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Schedule of Equity Method Investments [Line Items]
Initial capitalization of joint venture								$ 330,000,000
Purchases of land use rights in JV Company	$ 8,700,000
Parent Company [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Schedule of Equity Method Investments [Line Items]
Percent ownership in joint venture		51.00%
Chongqing Funds [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Schedule of Equity Method Investments [Line Items]
Percent ownership in joint venture		49.00%
Payments to acquire interest in joint venture			$ 33,000,000
Design Fees [Member] | Corporate Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Total price payable under EPC Contract						19,525,052	2,820,154
Construction and Procurement Fees [Member] | Corporate Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Total price payable under EPC Contract						¥ 520,474,948	$ 75,176,206

Joint Venture - Changes in Tota

Joint Venture - Changes in Total Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Balance, June 30, 2016			$ 242,039
Contributions from noncontrolling interest			33,000
Exercise of common stock options and release of RSUs			7,462
Issuance of shares under ESPP			1,166
Reissuance of treasury stock upon exercise of common stock options and release of RSUs			330
Withholding tax on restricted stock units			(1,915)
Stock-based compensation expense			4,585
Net income (loss)	$ 2,386	$ (1,263)	6,473	$ (4,849)
Net loss attributable to noncontrolling interest	(1,170)	$ 0	(3,237)	$ 0
Cumulative translation adjustment			(1,563)
Ending balance	291,577		291,577
Parent [Member]
Balance, June 30, 2016			242,142
Contributions from noncontrolling interest			0
Exercise of common stock options and release of RSUs			7,462
Issuance of shares under ESPP			1,166
Reissuance of treasury stock upon exercise of common stock options and release of RSUs			330
Withholding tax on restricted stock units			(1,915)
Stock-based compensation expense			4,585
Net income (loss)			9,710
Cumulative translation adjustment			(731)
Ending balance	262,749		262,749
Noncontrolling Interest [Member]
Balance, June 30, 2016			(103)
Contributions from noncontrolling interest			33,000
Exercise of common stock options and release of RSUs			0
Issuance of shares under ESPP			0
Reissuance of treasury stock upon exercise of common stock options and release of RSUs			0
Withholding tax on restricted stock units			0
Stock-based compensation expense			0
Cumulative translation adjustment			(832)
Ending balance	$ 28,828		$ 28,828

Shareholders' Equity and Shar38

Shareholders' Equity and Share-based Compensation - Shares Repurchase (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 07, 2015	Mar. 31, 2017	Mar. 31, 2017	Jun. 07, 2015	Apr. 30, 2015	Mar. 31, 2015
Class of Stock [Line Items]
Shares Repurchase Program Remaining Balance		$ 6.4	$ 6.4		$ 50	$ 17.8
Treasury Stock, Shares, Acquired		0	5,723,093
Treasury Stock, Value, Acquired, Cost Method			$ 50.8
Treasury stock acquired, average price per share (in dollars per share)			$ 8.87
Treasury Stock, Shares, Retired			0
Treasury Stock Reissued, Average Price Per Share			$ 5.79
Treasury Stock Reissued
Class of Stock [Line Items]
Treasury stock acquired, average price per share (in dollars per share)			$ 10.98
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)			110,153
Dutch Auction Tender Offer [Member] | Common Stock [Member]
Class of Stock [Line Items]
Share repurchase program, authorized amount (USD in Millions)				$ 30
Treasury Stock, Shares, Acquired	3,296,703
Treasury stock acquired, average price per share (in dollars per share)	$ 9.10

Shareholders' Equity and Shar39

Shareholders' Equity and Share-based Compensation - Share-based Compensation (Details) - USD ($)	3 Months Ended		9 Months Ended	77 Months Ended
	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2017	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury Stock, Shares, Acquired			0	5,723,093
Options, Weighted-Average Remaining Contractual Life (in years)		4 years 8 months 16 days	4 years 7 months 17 days
Options vested and expected to vest, Number Outstanding (in shares)	1,082,604		1,082,604	1,082,604
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share)	$ 10.97		$ 10.97	$ 10.97
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)			4 years 7 months 13 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 6,868,038		$ 6,868,038	$ 6,868,038
Options, Number Exercisable (in shares)	948,874		948,874	948,874
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 11.45		$ 11.45	$ 11.45
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	4 years 3 months 29 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 5,580,467		$ 5,580,467	$ 5,580,467
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at June 30, 2016			1,859,260
Granted (in shares)			0
Exercised (in shares)			(657,469)
Canceled or forfeited (in shares)			(112,500)
Outstanding at March 31, 2017	1,089,291	1,859,260	1,089,291	1,089,291
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at June 30, 2016 (in dollars per share)			$ 11.37
Granted (in dollars per share)			0
Exercised (in dollars per share)			11.85
Canceled or forfeited (in dollars per share)			12.72
Outstanding at March 31, 2017 (in dollars per share)	$ 10.95	$ 11.37	$ 10.95	$ 10.95
Options Outstanding Aggregate Intrinsic Value	$ 6,932,190	$ 5,959,720	$ 6,932,190	$ 6,932,190
Options Exercised Aggregate Intrinsic Value			$ 5,382,647
Employee Share Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility Rate			39.09%
Expected Term			1 year 3 months 18 days
Expected Dividend Rate			0.00%
Employee Share Purchase Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate			0.60%
Employee Share Purchase Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate			1.00%

Shareholders' Equity and Shar40

Shareholders' Equity and Share-based Compensation - Stock Options Outstanding and Exercisable (Details) - $ / shares	3 Months Ended	9 Months Ended
	Jun. 30, 2016	Mar. 31, 2017
Share-based Compensation [Abstract]
Options, Number Outstanding (in shares)	1,859,260	1,089,291
Options, Weighted-Average Remaining Contractual Life (in years)	4 years 8 months 16 days	4 years 7 months 17 days
Options, Weighted-Average Exercise Price (in dollars per share)	$ 11.37	$ 10.95
Options, Number Exercisable (in shares)		948,874
Options, Weighted-Average Exercise Price (in dollars per share)		$ 11.45
Options vested and expected to vest, Number Outstanding (in shares)		1,082,604
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)		4 years 7 months 13 days
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share)		$ 10.97

Shareholders' Equity and Shar41

Shareholders' Equity and Share-based Compensation - Restricted Stock Activity (Details) - USD ($)	3 Months Ended			9 Months Ended
	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
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 10 months 24 days
Allocated share-based compensation expense	$ 1,715,000		$ 1,173,000	$ 4,585,000	$ 3,047,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested at June 30, 2016				933,063
Granted				605,043
Vested				(328,226)
Forfeited				(21,725)
Nonvested at March 31, 2017	1,188,155	933,063		1,188,155
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonvested at June 30, 2016				$ 9.18
Granted				18.10
Vested				7.84
Forfeited				12.38
Nonvested at March 31, 2017	$ 14.04	$ 9.18		$ 14.04
Weighted Average Remaining Recognition Period (Years)	1 year 11 months 12 days	1 year 8 months 23 days
RSUs Nonvested Aggregate Intrinsic Value	$ 20,424,384	$ 12,997,568		$ 20,424,384
RSUs vested and expected to vest, Outstanding (in shares)	988,787			988,787
RSUs vested and expected to vest, Weighted Average Remaining Recognition Period (in years)	1 year 10 months 2 days
RSUs vested and expected to vest, Aggregate Intrinsic Value	$ 16,997,248			$ 16,997,248
Performance Based Restricted Stock Units (PRSUs) Member [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted	170,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Allocated share-based compensation expense	$ 68,000			$ 68,000

Shareholders' Equity and Shar42

Shareholders' Equity and Share-based Compensation - Share-based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 1,715	$ 1,173	$ 4,585	$ 3,047
Unrecognized compensation expense	$ 10,800		10,800
Recognition period of share-based compensation expense (in years)	1 year 10 months 24 days
Cost of goods sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 222	187	622	475
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	395	309	1,138	766
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 1,098	$ 677	$ 2,825	$ 1,806

Income Taxes - Narrative (Deta

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Mar. 31, 2017	Sep. 30, 2016	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Jun. 30, 2016
Related Party Transaction [Line Items]
Income tax expense	$ 523		$ 1,219	$ 2,845	$ 3,448
Estimated effective income tax rate	18.00%		(2770.50%)	30.50%	(246.10%)
Decrease in deferred tax assets		$ 6,600
Increase in prepaid tax asset		$ 6,600
Prepaid taxes, current and noncurrent	$ 5,800			$ 5,800
Prepaid taxes, current	1,100			1,100
Prepaid taxes, noncurrent	4,687			4,687		$ 0
Unrecognized tax benefits	6,400			6,400
Unrecognized tax benefit that would impact effective tax rate	$ 4,000			$ 4,000

Segment and Geographic Inform44

Segment and Geographic Information - Revenue by Location and Product Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 93,281	$ 82,987	$ 285,330	$ 244,251
Power discrete
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	70,794	63,464	212,044	182,769
Power IC
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	19,309	16,251	64,166	50,164
Packaging and testing services
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	3,178	3,272	9,120	11,318
Hong Kong
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	75,785	71,684	236,873	212,041
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	15,334	9,520	42,159	26,458
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	294	504	1,053	1,604
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,075	726	2,767	2,227
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 793	$ 553	$ 2,478	$ 1,921

Segment and Geographic Inform45

Segment and Geographic Information - Long-lived Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	$ 126,072	$ 116,084
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	68,528	64,272
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	56,875	51,214
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	$ 669	$ 598

Segment and Geographic Inform46

Segment and Geographic Information - Narratives (Details)	9 Months Ended
	Mar. 31, 2017Segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

Commitments and Contingencies -

Commitments and Contingencies - Purchase Commitments (Details) - USD ($) $ in Millions	Mar. 31, 2017	Jun. 30, 2016
Raw materials, wafers, and packaging and testing services puchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 31.2	$ 39.6
Property and equipment purchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 11.1	$ 6.6

Commitments and Contingencies48

Commitments and Contingencies - Guarantees (Details) - USD ($)	Mar. 31, 2017	Jun. 30, 2016
Indemnification Agreement
Loss Contingencies [Line Items]
Indemnifications accrual	$ 0	$ 0

Commitments and Contingencies49

Commitments and Contingencies - Other Investments (Details)	1 Months Ended	12 Months Ended
	Mar. 31, 2016	Jun. 30, 2017USD ($)	Jan. 10, 2017CNY (¥)	Jan. 10, 2017USD ($)	Mar. 29, 2016USD ($)
Corporate Joint Venture [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total price payable under EPC Contract			¥ 540,000,000	$ 77,996,360
Corporate Joint Venture [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Initial capitalization of joint venture					$ 330,000,000
Parent Company [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	51.00%
Chongqing Funds [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	49.00%
Scenario, Forecast [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Consideration transferred to acquire interest in joint venture		$ 10,000,000
Design Fees [Member] | Corporate Joint Venture [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total price payable under EPC Contract			19,525,052	2,820,154
Construction and Procurement Fees [Member] | Corporate Joint Venture [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total price payable under EPC Contract			¥ 520,474,948	$ 75,176,206