OmniVision (OVTI) 10-K 30 Jun 14 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 30, 2014	Jun. 23, 2014	Oct. 31, 2013
Document and Entity Information	'	'	'
Entity Registrant Name	'OMNIVISION TECHNOLOGIES INC	'	'
Entity Central Index Key	'0001106851	'	'
Document Type	'10-K	'	'
Document Period End Date	30-Apr-14	'	'
Amendment Flag	'false	'	'
Current Fiscal Year End Date	'--04-30	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Public Float	'	'	$779.10
Entity Common Stock, Shares Outstanding	'	56,510,879	'
Document Fiscal Year Focus	'2014	'	'
Document Fiscal Period Focus	'FY	'	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$297,952	$190,171
Short-term investments	152,993	22,164
Accounts receivable, net	172,472	166,517
Inventories	270,935	430,315
Deferred income taxes	4,973	4,028
Prepaid expenses and other current assets	6,576	11,982
Total current assets	905,901	825,177
Property, plant and equipment, net	153,792	158,394
Long-term investments	154,409	139,746
Goodwill	10,227	10,227
Intangibles, net	66,217	56,804
Other long-term assets	32,529	36,666
Total assets	1,323,075	1,227,014
Current liabilities:	'	'
Accounts payable	142,012	188,261
Accrued expenses and other current liabilities	31,959	40,274
Income taxes payable	2,316	2,904
Deferred revenues, less cost of revenues	25,783	15,493
Current portion of long-term debt	3,802	3,769
Total current liabilities	205,872	250,701
Long-term liabilities:	'	'
Long-term income taxes payable	86,498	90,777
Non-current portion of long-term debt	32,030	35,709
Other long-term liabilities	11,818	4,618
Total long-term liabilities	130,346	131,104
Total liabilities	336,218	381,805
Commitments and contingencies (Note 16)	'	'
Stockholders' equity:	'	'
Common stock, $0.001 par value; 100,000,000 shares authorized; 76,680,773 shares issued and 56,081,586 outstanding at April 30, 2014 and 74,574,382 shares issued and 53,975,195 outstanding at April 30, 2013, respectively	77	75
Additional paid-in capital	664,602	616,379
Accumulated other comprehensive income	2,378	3,952
Treasury stock, 20,599,187 shares at April 30, 2014 and April 30, 2013	-278,683	-278,683
Retained earnings	598,483	503,486
Total stockholders' equity	986,857	845,209
Total liabilities and stockholders' equity	$1,323,075	$1,227,014

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Apr. 30, 2014	Apr. 30, 2013
CONSOLIDATED BALANCE SHEETS	'	'
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	76,680,773	74,574,382
Common stock, shares outstanding	56,081,586	53,975,195
Treasury stock, shares	20,599,187	20,599,187

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
CONSOLIDATED STATEMENTS OF INCOME	'	'	'
Revenues	$1,453,929	$1,407,929	$897,730
Cost of revenues	1,178,207	1,163,815	649,719
Gross profit	275,722	244,114	248,011
Operating expenses:	'	'	'
Research, development and related	119,248	113,194	110,730
Selling, general and administrative	73,292	72,958	63,883
Amortization of acquired patent portfolio	9,286	9,286	9,286
Total operating expenses	201,826	195,438	183,899
Income from operations	73,896	48,676	64,112
Benefit from acquisition of production operations from VisEra	3,057	'	8,626
Equity in earnings of investee	4,009	3,832	3,066
Interest expense, net	-2,029	-2,700	-2,106
Other income (expense), net	25,996	356	-1,050
Income before income taxes	104,929	50,164	72,648
Provision for income taxes	9,932	7,262	6,799
Net income	$94,997	$42,902	$65,849
Net income per share:	'	'	'
Basic (in dollars per share)	$1.71	$0.80	$1.16
Diluted (in dollars per share)	$1.70	$0.80	$1.13
Shares used in computing net income per share:	'	'	'
Basic (in shares)	55,537	53,529	56,666
Diluted (in shares)	56,043	53,671	58,233

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME	'	'	'
Net income	$94,997	$42,902	$65,849
Other comprehensive income (loss), net of tax:	'	'	'
Translation gains	35	280	1,883
Reclassification adjustments for gains on sale of WLCSP included in net income, net of tax	-665	'	'
'Translation gains (losses)	-630	280	1,883
Unrealized gains (losses) on available-for-sale securities	343	691	-339
Reclassification adjustments for (gains) losses on available-for-sale securities included in net income, net of tax	-1,287	11	'
Unrealized gains (losses) on available-for-sale securities, net	-944	702	-339
Other comprehensive income (loss)	-1,574	982	1,544
Comprehensive income	$93,423	$43,884	$67,393

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Treasury Stock	Retained Earnings
In Thousands, except Share data, unless otherwise specified
Balance at Apr. 30, 2011	$751,325	$71	$533,776	$1,426	($178,683)	$394,735
Balance (in shares) at Apr. 30, 2011	'	57,974,450	'	'	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'	'
Exercise of common stock options	13,649	1	13,648	'	'	'
Exercise of common stock options (in shares)	'	885,450	'	'	'	'
Employee stock purchase plan	5,936	'	5,936	'	'	'
Employee stock purchase plan (in shares)	'	582,363	'	'	'	'
Restricted stock units	1	1	'	'	'	'
Restricted stock units (in shares)	'	980,572	'	'	'	'
Withholding tax deduction on restricted stock units	-3,310	'	-3,310	'	'	'
Purchase of stock for treasury	-100,000	'	'	'	-100,000	'
Purchase of stock for treasury (in shares)	'	-8,058,187	'	'	'	'
Employee stock-based compensation	27,324	'	27,324	'	'	'
Tax effect from stock-based compensation	897	'	897	'	'	'
Write-off of employee stock-based compensation related deferred tax assets	-2,336	'	-2,336	'	'	'
Translation gains (losses)	1,883	'	'	1,883	'	'
Unrealized gains (losses) on available-for-sale securities, net	-339	'	'	-339	'	'
Net income	65,849	'	'	'	'	65,849
Balance at Apr. 30, 2012	760,879	73	575,935	2,970	-278,683	460,584
Balance (in shares) at Apr. 30, 2012	'	52,364,648	'	'	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'	'
Exercise of common stock options	1,085	'	1,085	'	'	'
Exercise of common stock options (in shares)	'	136,563	'	'	'	'
Employee stock purchase plan	6,721	1	6,720	'	'	'
Employee stock purchase plan (in shares)	'	687,566	'	'	'	'
Restricted stock units	1	1	'	'	'	'
Restricted stock units (in shares)	'	786,418	'	'	'	'
Withholding tax deduction on restricted stock units	-1,561	'	-1,561	'	'	'
Employee stock-based compensation	33,511	'	33,511	'	'	'
Tax effect from stock-based compensation	3,696	'	3,696	'	'	'
Write-off of employee stock-based compensation related deferred tax assets	-1,637	'	-1,637	'	'	'
Tax payable adjustment	-1,370	'	-1,370	'	'	'
Translation gains (losses)	280	'	'	280	'	'
Unrealized gains (losses) on available-for-sale securities, net	702	'	'	702	'	'
Net income	42,902	'	'	'	'	42,902
Balance at Apr. 30, 2013	845,209	75	616,379	3,952	-278,683	503,486
Balance (in shares) at Apr. 30, 2013	53,975,195	53,975,195	'	'	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'	'
Exercise of common stock options	6,825	'	6,825	'	'	'
Exercise of common stock options (in shares)	'	465,468	'	'	'	'
Employee stock purchase plan	6,848	1	6,847	'	'	'
Employee stock purchase plan (in shares)	'	683,405	'	'	'	'
Restricted stock units	1	1	'	'	'	'
Restricted stock units (in shares)	'	957,518	'	'	'	'
Withholding tax deduction on restricted stock units	-2,803	'	-2,803	'	'	'
Employee stock-based compensation	35,043	'	35,043	'	'	'
Tax effect from stock-based compensation	3,042	'	3,042	'	'	'
Write-off of employee stock-based compensation related deferred tax assets	-731	'	-731	'	'	'
Translation gains (losses)	-630	'	'	-630	'	'
Unrealized gains (losses) on available-for-sale securities, net	-944	'	'	-944	'	'
Net income	94,997	'	'	'	'	94,997
Balance at Apr. 30, 2014	$986,857	$77	$664,602	$2,378	($278,683)	$598,483
Balance (in shares) at Apr. 30, 2014	56,081,586	56,081,586	'	'	'	'

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Cash flows from operating activities:	'	'	'
Net income	$94,997	$42,902	$65,849
Adjustments to reconcile net income to net cash provided by (used in) operating activities:	'	'	'
Depreciation and amortization	32,726	32,524	29,771
Change in fair value of interest rate swap	-1,204	-625	880
Stock-based compensation	35,043	33,511	27,324
Tax effect from stock-based compensation	3,042	3,696	897
Gain on equity investments, net	-19,459	-20,014	-10,403
Write-down of inventories	33,172	23,122	17,100
Excess tax benefits from stock-based compensation	-2,538	-2,696	-475
Benefit from acquisition of production operations from VisEra	-3,057	'	-8,626
Gain associated with WLCSP IPO	-23,802	'	'
Gain on sale of investment in Tong Hsing	-1,990	'	'
(Gain) loss on disposal of property, plant and equipment	-154	152	-36
Changes in assets and liabilities:	'	'	'
Accounts receivable, net	-5,956	-58,724	34,813
Inventories	128,773	-163,513	-204,588
Deferred income taxes	8,272	-4,361	2,921
Prepaid expenses and other assets	2,772	10,203	2,139
Accounts payable	-47,236	29,902	58,169
Accrued expenses and other liabilities	-1,137	5,251	-2,384
Income taxes payable	-4,867	3,248	1,619
Deferred revenues, less cost of revenues	10,496	4,798	-6,533
Net cash provided by (used in) operating activities	237,893	-60,624	8,437
Cash flows from investing activities:	'	'	'
Purchases of short-term investments	-228,244	-309,345	-185,264
Proceeds from sales or maturities of short-term investments	96,211	327,161	231,332
Purchases of property, plant and equipment, net of sales	-14,849	-35,323	-24,186
Purchase and deposits for intangible and other assets	-12,302	-20,557	-6,500
Purchase of Phostek shares	'	'	-2,000
Proceeds from sale of investment in WLCSP	14,936	'	'
Proceeds from sale of (purchases of) investment in Tong Hsing	6,224	'	-421
Payments for the acquisition of production operations from VisEra	'	-9,000	-26,000
Net cash used in investing activities	-138,024	-47,064	-13,039
Cash flows from financing activities:	'	'	'
Repayment of long-term borrowings	-3,830	-3,144	-4,341
Excess tax benefits from stock-based compensation	2,538	2,696	475
Proceeds from exercise of stock options and employee stock purchase plan	13,673	7,807	19,586
Final payment for acquisition of production operation from VisEra	-4,500	'	'
Payments for repurchases of common stock	'	'	-100,000
Net cash provided by (used in) financing activities	7,881	7,359	-84,280
Effect of exchange rate changes on cash and cash equivalents	31	8	-5
Net increase (decrease) in cash and cash equivalents	107,781	-100,321	-88,887
Cash and cash equivalents at beginning of period	190,171	290,492	379,379
Cash and cash equivalents at end of period	297,952	190,171	290,492
Supplemental cash flow information:	'	'	'
Taxes paid	3,425	4,611	1,931
Interest paid	2,373	2,570	2,716
Supplemental schedule of non-cash investing and financing activities:	'	'	'
Additions to intangible assets included in accruals	9,604	'	'
Acquisition of production operations from VisEra included in accrued expenses and other long-term liabilities	'	'	16,923
Additions to property, plant and equipment included in accounts payable and accrued expenses and other current liabilities	3,877	2,500	2,425
Write-off of employee stock-based compensation-related deferred tax assets	$731	$1,637	$2,336

Basis_of_Presentation

Basis of Presentation	12 Months Ended
	Apr. 30, 2014
Basis of Presentation	'
Basis of Presentation	'
	Note 1—Basis of Presentation
	The Company
	OmniVision Technologies, Inc. and its subsidiaries ("OmniVision" or the "Company") design, develop, manufacture and market image-sensor devices. The Company's main product, a semiconductor image-sensing device called the CameraChip™, is used to capture images electronically and is used in a number of consumer and commercial mass-market applications. The Company's CameraChip image sensor is manufactured using the complementary metal oxide semiconductor ("CMOS") fabrication process. The Company has also integrated its CameraChip image sensor with wafer-level optics, and marketed the integrated device as a CameraCubeChip™ imaging device. The Company was incorporated in California in May 1995 and reincorporated in Delaware in March 2000.
	The results of operations for the fiscal year ended April 30, 2014 are not necessarily indicative of the results that may be expected for the fiscal year ending April 30, 2015 or any other future period.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and judgments on its historical experience, knowledge of current conditions and beliefs of what could occur in the future considering available information. Actual results could differ from these estimates.
	Equity in Earnings of China WLCSP Limited
	The Company applies the equity method of accounting for its investment in China WLCSP Limited ("WLCSP"), and the Company's portion of net income recorded by WLCSP is presented in "Equity in earnings of investee." Through October 31, 2013, the Company was able to include in its fiscal quarter results its share of WLCSP's earnings or losses for the same fiscal periods. In January 2014, however, WLCSP completed its initial public offering and became a public company in China. (See Note 5.) Under China's securities laws, the Company is not able to disclose any periodic financial information about WLCSP which may otherwise be available to the Company in its capacity as a representative on WLCSP's Board of Directors, until such information is publicly released in China. Furthermore, WLCSP will only report its earnings on a calendar-quarter basis. Consequently, starting with the fourth quarter of fiscal 2014, the Company introduced a one-month lag in its equity method of accounting for WLCSP. For fiscal 2014, under "Equity in earnings of investee," the Company only included its share of WLCSP's earnings from May 1, 2013 to March 31, 2014. For fiscal quarters beginning after May 1, 2014, the Company will include in its results of operations its share of WLCSP's earnings or losses from the calendar quarter that is one month in arrears. The introduction of a one-month lag in the equity method of accounting for WLCSP has no material effects on any prior years' or the current year's consolidated balance sheets, statements of income or cash flows. Accordingly, prior years' financial statements have not been recast to reflect the new policy.
	Classification of land use Rights
	Certain previously reported amounts have been revised to correct the classification of land-use rights from "Property, plant and equipment, net" to "Other long-term assets" as of April 30, 2013. The net book value of the Company's land-use rights totaled approximately $2.2 million at April 30, 2014 and April 30, 2013, respectively. The reclassification had no impact on the results of operations or cash flows of the Company.
	The net book value of the Company's land-use rights comprises three separate arrangements. One of the Company's wholly-owned subsidiaries, OmniVision Semiconductor (Shanghai) Co. Ltd. ("OSC"), formerly Hua Wei Semiconductor (Shanghai) Co. Ltd., holds a land-use right that was acquired from the Shanghai SongJiang Housing and Land Administration Bureau in December 2000 for approximately $0.8 million. The cost of the land-use right is being amortized over 40 years, the useful life of the right.
	In January 2007, the Company, through its wholly-owned subsidiary, OmniVision Technologies (Shanghai) Co. Ltd. ("OTC"), formerly Shanghai OmniVision IC Design Co. Ltd., entered into a land-use-right agreement with the Construction and Transportation Commission of the Pudong New District, Shanghai. The agreement has an effective date of December 31, 2006. Under the terms of the agreement, the Company paid an aggregate amount of approximately $0.6 million in exchange for the right to use approximately 323,000 square feet of land located in Shanghai, China. The cost of the land-use right is being amortized over 50 years, the useful life of the right.
	In addition, in July 2011, the Company, through its wholly-owned subsidiary, Shanghai OmniVision Semiconductor Technology Co. Ltd. ("OST"), entered into a land-use-right agreement with the Shanghai SongJiang District Zoning and Land Administration Bureau. Under the terms of the agreement, the Company paid an aggregate amount of approximately $1.0 million in exchange for the right to use approximately 113,175 square feet of land located in Shanghai for a period of 50 years, starting from August 19, 2011. The cost of the land-use right is being amortized over 50 years, the useful life of the right.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Apr. 30, 2014
Summary of Significant Accounting Policies	'
Summary of Significant Accounting Policies	'
	Note 2—Summary of Significant Accounting Policies
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant inter-company accounts and transactions have been eliminated.
	Foreign Currency Translation
	All of the Company's wholly-owned subsidiaries use the U.S. dollar as their respective functional currency. For these subsidiaries with assets or liabilities denominated in currencies other than the U.S. dollar, non-monetary assets are remeasured into U.S. dollars using historical rates of exchange. Monetary assets and liabilities are remeasured into U.S. dollars using exchange rates prevailing on the balance sheet date. The remeasurement gains or losses are included in "Other income (expense), net." For fiscal 2014 and 2013, the Company recorded remeasurement losses of $1.5 million and $405,000 in "Other income (expense), net," respectively. For fiscal 2012, the Company recorded a remeasurement gain of $117,000 in "Other income (expense), net."
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with a maturity at the date of purchase of three months or less to be cash equivalents. Cash equivalents consist principally of money market funds. (See Note 4.)
	The Company maintains the majority of its cash and cash equivalent balances with major financial institutions in the United States, Cayman Islands and Singapore. These balances are subject to a concentration of credit risk and only a small proportion of these balances are covered by Federal Deposit Insurance Corporation ("FDIC") insurance. The Company places its cash investments in instruments that meet high credit quality standards, as specified in the Company's investment policy guidelines.
	Short-Term Investments
	The Company's short-term investments, which are classified as available-for-sale securities, are invested in high-grade corporate securities, municipal bonds and notes and U.S. government debt and agencies securities with a final maturity of eighteen months or less from the date of purchase.
	Short-term investments are reported at fair value at April 30, 2014 and 2013. Unrealized gains or losses are recorded in stockholders' equity and included in "Accumulated other comprehensive income." Short-term investments with declines in value which are judged to be other than temporary, of which there were none in the periods presented, would be written down to their fair values, at the time such judgment is made.
	Accounts Receivable
	Accounts receivable are recorded at invoiced amounts and do not bear interest. The Company performs ongoing credit evaluations of its customers' financial condition and, generally, requires no collateral from its customers. Allowances for doubtful accounts and sales returns are established based on various factors including credit profiles of the Company's customers, contractual terms and conditions, historical payments, returns and discounts experience, and current economic trends. The Company reviews its allowance for doubtful accounts quarterly by assessing individual accounts receivable over a specific aging and amount, and all other balances on a pooled basis based on historical collection experience and economic risk assessment. Accounts receivable are written off on a case-by-case basis, net of any amounts that may be collected. The Company determines its allowance for sales returns through evaluation of historical sales returns and other known factors and provides for estimated sales returns in the same period it records the related revenues. To estimate the allowance for sales returns, the Company analyzes potential customer specific product application issues, potential quality and reliability issues and historical returns. The Company evaluates the adequacy of the allowance for sales returns on a quarterly basis. This allowance is reflected as a reduction to accounts receivable in the Company's consolidated balance sheets. Increases to the allowance are recorded as a reduction to revenues.
	Fair Value of Financial Instruments
	Due to their short maturities, the reported amounts of the Company's financial instruments, including cash equivalents, short-term investments, accounts receivable, accounts payable and other current liabilities approximate fair value.
	The fair values of the Company's mortgage loan and construction loan approximate book value as the underlying interest rates are based on risk-adjusted market rates. (See Note 7.)
	Related to the mortgage debt, the Company has one outstanding interest rate swap arrangement as of April 30, 2014. The Company recognizes this derivative instrument at the reporting date as either an asset or liability in its Consolidated Balance Sheets, measured at fair value. The accounting for changes in fair value of a derivative depends on the intended use of the derivative and the associated hedging designation. The Company has designated the swap as an economic hedge and records the changes in fair value in "Other income (expense), net." (See Note 7.)
	Property, Plant and Equipment
	Property, plant and equipment is stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets as follows:
	Buildings	40 years
	Building/leasehold improvements	Shorter of 20 years or life of lease
	Machinery and equipment	2 - 10 years
	Furniture and fixtures	3 - 7 years
	Construction in progress includes project costs paid to third parties that are clearly associated with the acquisition, development, and construction of an asset and are capitalized as a cost of that project prior to the use of the asset. Such costs include the costs of materials, interest, legal, and escrow services. These capitalized project costs are not subject to depreciation until the assets to which they are related are placed into production.
	Long-Lived Assets
	The Company reviews its long-lived assets, including intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. When such an event occurs, the Company estimates the undiscounted future cash flows expected to result from the use of the asset and its eventual disposition. If the undiscounted expected future cash flows are less than the carrying amount of the asset, an impairment loss is recognized in order to write-down the carrying value of the asset to its estimated fair market value. To date, the Company has not recognized any impairment losses.
	Inventories
	Inventories are stated at the lower of cost, determined on a first-in, first-out ("FIFO") basis, or market.
	The Company records a provision to reduce the carrying value of inventories to their net realizable value when the Company believes that the net realizable value is less than cost. The Company also records a provision for the cost of inventories when the number of units on hand exceeds the number of units that the Company forecasts will be sold over a certain period of time, generally 12 months. Where necessary, these provisions take into account the inventories owned and not yet sold by certain of the Company's distributors. The recording of these provisions establishes a new and lower cost basis for each specifically identified inventory item, and the Company does not restore the cost basis to its original level regardless of any subsequent changes in facts or circumstances. Recoveries are only recognized upon the sale of previously written-down inventories.
	Goodwill
	The Company records goodwill when the consideration paid for an acquisition exceeds the fair value of net tangible and intangible assets acquired, including related tax effects. Goodwill is not amortized; instead goodwill is tested for impairment on an annual basis, or more frequently if the Company believes indicators of impairment exist. The Company first assesses qualitative factors to determine whether it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value. If the Company determines that the fair value is less than the carrying value, the Company will use a two-step process to determine the amount of goodwill impairment. The first step requires comparing the fair value of the reporting unit to its net book value, including goodwill. A potential impairment exists if the fair value of the reporting unit is lower than its net book value. The second step of the process, which is performed only if a potential impairment exists, involves determining the difference between the fair value of the reporting unit's net assets other than goodwill and the fair value of the reporting unit. If this difference is less than the net book value of goodwill, an impairment exists and is recorded.
	Warranty for Defective Products
	The Company warrants to its customers that its products will work in accordance with each product's specifications. Due to the cost and other complexities associated with rectifying any product defects, the Company does not repair any defective products. If a product is defective, the customer notifies the Company and, with the Company's approval, returns the defective product. The Company then sends replacement products to the customer. Accordingly, the Company accounts for any exposure related to defective products as a portion of its allowance for sales returns.
	Treasury Stock
	The Company accounts for treasury stock under the cost method and includes treasury stock as a component of stockholders' equity.
	Revenue Recognition
	For shipments to customers without agreements that allow for returns or credits, principally original equipment manufacturers ("OEMs") and value added resellers ("VARs"), the Company recognizes revenue using the "sell-in" method. Under this method, the Company recognizes revenue upon the shipment of products to the customer provided that the Company has received a signed purchase order, the price is fixed or determinable, title and risk of loss has transferred to the customer, collection of resulting receivables is considered reasonably assured, product returns are reasonably estimable, there are no customer acceptance requirements and there are no remaining material obligations. At the time revenue is recognized, the Company provides for future returns of potentially defective product based on historical experience. For cash consideration given to customers, that is primarily in the form of rebates and for which the Company does not receive a separately identifiable benefit or cannot reasonably estimate fair value, the Company records the amounts as reductions of revenue.
	For shipment of products sold to distributors under agreements allowing for returns or credits, title and the risk of ownership to the products transfer to the distributor upon shipment, and the distributor is obligated to pay for the products whether or not the distributor has sold them at the time payment is due. Under the terms of the Company's agreements with such distributors and subject to the Company's prior approval, distributors are entitled to reclaim from the Company as price adjustments the difference, if any, between the prices at which the Company sold the product to the distributors and the prices at which the product is subsequently sold by the distributor. In addition, distributors have limited rights to return inventory that they determine is in excess of their requirements, and accordingly, in determining the appropriate level of provision for excess and obsolete inventory, the Company takes into account the inventories held by its distributors. For these reasons, the price is not considered fixed or determinable until the distributor resells the products to the Company's end-user customers and the distributor notifies the Company in writing of the details of such sales transactions. Accordingly, the Company recognizes revenue using the "sell-through" method. Under the "sell-through" method, the Company defers the revenue, adjustments to revenue and the related costs of revenue until the final resale of such products to end customers. The amounts billed to these distributors and adjustments to revenue and the cost of inventory shipped to, but not yet sold by, the distributors are shown net on the Consolidated Balance Sheets as "Deferred revenues, less cost of revenues."
	Research, Development and Related
	The Company recognizes the costs associated with the internal development of intellectual property rights as expense when incurred. Also included in "Research, Development and Related" are expenses associated with patent, copyright, trademark and trade secrets. The Company recorded the following research and development expenses for the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Research and development expenses	$	114,224	$	109,026	$	106,587
	Amortization of Acquired Patent Portfolio
	The Company recognizes amortization expense associated with the patent portfolio acquired from Eastman Kodak Company ("Kodak") in March 2011 as "Amortization of acquired patent portfolio."
	Advertising
	All of the Company's advertising costs are expensed as incurred.
	Income Taxes
	The Company accounts for deferred income taxes using the liability method, under which it recognizes as deferred tax assets and liabilities the expected future tax consequences of timing differences between the book and tax basis of assets and liabilities. The Company establishes valuation allowances to reduce deferred tax assets as necessary when management estimates, based on available objective evidence, that it is more-likely-than-not that the Company will not realize the benefit of its deferred tax assets.
	The Company recognizes in its consolidated financial statements the impact of a tax position that, based on the technical merits of the position, is more-likely-than-not to be sustained upon examination. The evaluation of a tax position in accordance with this interpretation is a two-step process. In the first step, recognition, the Company determines whether it is more-likely-than-not that a tax position will be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. The second step addresses measurement of a tax position that meets the more-likely-than-not criterion. The tax position is measured at the largest amount of benefit that has a greater than 50 percent likelihood of being realized upon ultimate settlement. Tax positions that previously failed to meet the more-likely-than-not recognition threshold will be recognized in the first subsequent financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more-likely-than-not recognition threshold will be de-recognized in the first subsequent financial reporting period in which that threshold is no longer met.
	Stock-Based Compensation
	The Company recognizes in its consolidated financial statements all share-based payments to employees, including grants of employee stock options and of other stock-based compensation under the 2007 Equity Incentive Plan and the 2000 Stock Plan, and employee stock purchases under the 2009 Employee Stock Purchase Plan and the 2000 Employee Stock Purchase Plan, based on their respective measurement date fair values. The 2007 Equity Incentive Plan replaced the 2000 Stock Plan, and the 2009 Employee Stock Purchase Plan replaced the 2000 Employee Stock Purchase Plan.
	Stock-based compensation is measured at the measurement date, based on the fair value of the award. For stock options, fair value is measured using the Black-Scholes option pricing model ("Black-Scholes"), and for restricted stock units, fair value is based on the market price of the Company's common stock. The expenses are recognized over the requisite service period of the award. The Company has chosen to recognize stock-based compensation expense using the straight-line attribution method. Black-Scholes requires the use of highly subjective, complex assumptions, including the expected term and the price volatility of the Company's stock. The Company is required to estimate forfeiture rates at the time of grant and revise such estimates, if necessary, in subsequent periods if actual forfeitures differ from initial estimates. Stock-based compensation expense was recorded net of estimated forfeitures such that expense was recorded only for those stock-based awards that are expected to vest.
	The Company elected to use the long-form method to establish the beginning balance of, and to determine the subsequent impact on, the additional paid-in capital pool. The Company has also elected to use the "with and without" approach in determining the order in which tax attributes are utilized. As a result, the Company will recognize a tax benefit from stock-based awards in additional paid-in capital only if an incremental tax benefit is realized after all other tax attributes currently available to the Company have been utilized. In addition, the Company has elected to account for the indirect effects of stock-based awards on other tax attributes, such as research and development tax credits, through the Consolidated Statements of Income.
	Basic and Diluted Net Income Per Share
	The Company computes net income per share in accordance with authoritative guidance for earnings per share, under the provisions of which basic income per share is computed by dividing the income available to holders of common stock for the period by the weighted average number of shares of common stock outstanding during the period. The calculation of diluted net income per share excludes potential common stock if the effect of such stock is antidilutive. Potential common stock consists of incremental common shares issuable upon the exercise of stock options, purchases via employee stock purchase plans, and vesting of restricted stock units.
	Recent Accounting Pronouncements
	In March 2013, the Financial Accounting Standards Board ("FASB") revised the authoritative guidance on accounting for cumulative translation adjustment. The revised guidance specifies that a cumulative translation adjustment should be released into earnings when an entity ceases to have a controlling financial interest in a subsidiary or a group of assets within a consolidated foreign entity and the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For sales of an equity method investment that is a foreign entity, a pro rata portion of cumulative translation adjustment attributable to the investment would be recognized in earnings upon sale of the investment. The guidance is effective for the Company beginning in the first quarter of fiscal 2015. The Company does not expect the adoption of this guidance to have any material impact on its financial position, results of operations or cash flows.
	In July 2013, the FASB issued final guidance on the presentation of certain unrecognized tax benefits in the financial statements. Under the new guidance, a liability related to an unrecognized tax benefit would be offset against a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax position is disallowed. The guidance is effective for the Company beginning in the first quarter of fiscal 2015. The Company expects that its long-term income taxes payable to decrease and its deferred tax liabilities—non-current to increase in the first quarter of fiscal 2015 as a result of the adoption of this guidance.
	In April 2014, the FASB revised the authoritative guidance on reporting discontinued operations. The revised guidance specifies that a disposal of a component of an entity or a group of components of an entity is required to be reported in a discontinued operation if the disposal represents a strategic shift that has, or will have a major effect on an entity's operations and financial results. The guidance also changes the requirements for reporting discontinued operations which requires additional disclosures for discontinued operations and new disclosures for individually material disposal transactions that do not meet the definition of a discontinued operation. The guidance is effective for the Company beginning in the first quarter of fiscal 2016. The Company is currently evaluating the impact this guidance may have on its financial position, results of operations and cash flows.

ShortTerm_Investments

Short-Term Investments	12 Months Ended
	Apr. 30, 2014
Short-Term Investments	'
Short-Term Investments	'
	Note 3—Short-Term Investments
	Available-for-sale securities as of the dates presented were as follows (in thousands):
		As of April 30, 2014
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
	Municipal bonds	$	6,168	$	1	$	(2	)	$	6,167
	Corporate debt securities/commercial paper		146,866		6		(46	)		146,826
		$	153,034	$	7	$	(48	)	$	152,993
	Contractual maturity dates, less than one year								$	142,758
	Contractual maturity dates, one to two years									10,235
									$	152,993
		As of April 30, 2013
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
	Municipal bonds	$	1,707	$	—	$	—		$	1,707
	Corporate debt securities/commercial paper		20,463		—		(6	)		20,457
		$	22,170	$	—	$	(6	)	$	22,164
	Contractual maturity dates, less than one year								$	20,764
	Contractual maturity dates, two to twenty-three years									1,400
									$	22,164
	The Company sold available-for-sale investments, primarily marketable debt instruments, for proceeds of approximately $35.5 million, $275.3 million and $151.6 million in fiscal 2014, 2013 and 2012, respectively. The Company employs the specific-identification method in the determination of any applicable gain or loss on the sale of the investment.

Supplemental_Balance_Sheet_Acc

Supplemental Balance Sheet Account Information (in thousands)	12 Months Ended
	Apr. 30, 2014
Supplemental Balance Sheet Account Information (in thousands)	'
Supplemental Balance Sheet Account Information (in thousands)	'
	Note 4—Supplemental Balance Sheet Account Information (in thousands)
		April 30,
		2014			2013
	Cash and cash equivalents:
	Cash	$	195,141		$	145,762
	Money market funds and U.S. government bonds		102,811			44,409
		$	297,952		$	190,171
	Accounts receivable, net:
	Accounts receivable	$	176,576		$	172,833
	Less: Allowance for doubtful accounts		(998	)		(945	)
	Allowance for sales returns		(3,106	)		(5,371	)
		$	172,472		$	166,517
	Inventories:
	Work in progress	$	107,621		$	213,095
	Finished goods		163,314			217,220
		$	270,935		$	430,315
	Prepaid expenses and other current assets:
	Prepaid expenses	$	4,285		$	7,974
	Deposits and other		1,284			3,907
	Interest receivable		1,007			101
		$	6,576		$	11,982
	Property, plant and equipment, net:
	Land	$	13,000		$	13,000
	Buildings		82,547			57,246
	Buildings/leasehold improvements		29,123			24,659
	Machinery and equipment		119,762			102,429
	Furniture and fixtures		5,002			5,013
	Software		8,774			6,954
	Construction in progress		2,894			37,725
			261,102			247,026
	Less: Accumulated depreciation and amortization		(107,310	)		(88,632	)
		$	153,792		$	158,394
	Other long-term assets:
	Deferred tax assets—non-current	$	528		$	6,251
	Land-use rights		2,180			2,236
	Other long-term assets		29,821			28,179
		$	32,529		$	36,666
	Accrued expenses and other current liabilities:
	Due to VisEra for acquisition of production operations	$	—		$	9,000
	Deferred tax liabilities—current		144			—
	Employee compensation		15,176			12,856
	Third party commissions		380			850
	Professional services		2,270			2,176
	Noncancelable purchase commitments		647			4,817
	Rebates		1,511			2,557
	Other		11,831			8,018
		$	31,959		$	40,274
	Other long-term liabilities:
	Interest rate swap	$	2,980		$	4,184
	Deferred tax liabilities—non-current		3,731			—
	Other		5,107			434
		$	11,818		$	4,618

LongTerm_Investments

Long-Term Investments	12 Months Ended
	Apr. 30, 2014
Long-Term Investments	'
Long-Term Investments	'
	Note 5—Long-Term Investments
	Long-term investments as of the dates indicated consisted of the following (in thousands):
		April 30,
		2014		2013
	VisEra	$	115,943	$	105,233
	WLCSP		33,805		22,539
	XinTec		4,661		4,661
	Tong Hsing		—		5,313
	Phostek		—		2,000
	Total	$	154,409	$	139,746
	VisEra Technologies Company, Ltd.
	On October 29, 2003, the Company and Taiwan Semiconductor Manufacturing Company Limited ("TSMC") entered into an agreement to form VisEra Technologies Company, Ltd. ("VisEra"), a joint venture in Taiwan, for the purposes of providing certain manufacturing and automated final testing services related to complementary metal oxide semiconductor ("CMOS") image sensors. In August 2005, under an amendment to the original 2003 joint-venture agreement, the Company and TSMC formed VisEra Holding Company ("VisEra Cayman"), a company incorporated in the Cayman Islands, and VisEra became a subsidiary of VisEra Cayman. The Company and TSMC have equal interests in VisEra Cayman. As of April 30, 2014, the Company owned 49.1% of VisEra Cayman.
	On June 20, 2011, the Company entered into an agreement with VisEra to acquire from VisEra its CameraCubeChip production operations. The acquisition of the production operations was completed in October 2011, and the Company accounted for the transaction as a business combination. Under the terms of the agreement, the closing consideration was $42.9 million in cash. In April 2014, due to the lack of commercial viability for certain milestone deliverables, the Company agreed with VisEra to reduce the final installment of cash consideration from $9.0 million to $4.5 million. Consequently, the Company recorded a $3.1 million post-acquisition gain in "Benefit from acquisition of production operations from VisEra," representing the $4.5 million reduction in the final installment payment, net of a $1.4 million equity method elimination for the corresponding receivable write-off recorded by VisEra. The Company paid the final $4.5 million to VisEra in April 2014.
	The Company received the following dividend payments from VisEra during the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Dividend payments received from VisEra	$	—	$	13,760	$	—
	The Company accounts for its investment in VisEra under the equity method. The following table presents equity income before elimination of unrealized intercompany profits and the equity income recorded by the Company for the periods indicated in "Cost of revenues," consisting of its portion of the net income recorded by VisEra during the periods presented after the elimination of unrealized intercompany profits (in thousands).
		Year Ended April 30,
		2014		2013		2012
	Equity income	$	10,710	$	20,274	$	8,835
	Net effect on Cost of revenues, after the elimination of unrealized intercompany profits	$	17,228	$	15,752	$	7,326
	China WLCSP Limited
	China WLCSP Limited ("WLCSP") is in the business of designing, manufacturing, packaging and selling certain wafer level chip scale packaging related services. In May 2007, the Company acquired 4,500,000 units of WLCSP's equity interests, or 20.0% of WLCSP's registered capital on a fully-diluted basis, for an aggregate purchase amount of $9.0 million. In April 2010, WLCSP raised additional capital and reduced the Company's ownership percentage to 19.7%. In May 2010, WLCSP converted all of its owners' equity into share capital. The pro rata interests of all shareholders remained the same after the conversion and no income was distributed. After the conversion, WLCSP had 180.0 million shares outstanding, and the Company owned 35.4 million shares. In September 2010, WLCSP issued an additional 9.5 million shares to other parties and reduced the Company's ownership percentage to 18.7%.
	The Company has a seat on the WLCSP Board of Directors. With the determination that the Company has maintained significant influence over the operations of WLCSP, the Company accounts for its investment in WLCSP under the equity method.
	In December 2013, WLCSP filed with the China Securities Regulatory Commission ("CSRC") a registration statement for an initial public offering ("IPO"). The registration statement was approved by the CSRC in January 2014, and the IPO price was approximately $3.14 per share. As part of the IPO, WLCSP issued 37.2 million new shares and increased the total shares outstanding to 226.7 million shares. The Company also participated in the IPO as selling shareholder and sold 5.1 million shares, reducing the total number of shares owned by the Company to 30.3 million shares.
	The issuance price of $3.14 for the 37.2 million new shares was higher than the Company's average per share carrying value for WLCSP. Consequently, the Company recognized a non-cash change-in-interest gain of approximately $14.1 million. In addition, with the sale of 5.1 million shares during the IPO, the Company recorded a receivable for the net cash proceeds of approximately $15.1 million, and recognized approximately $9.7 million as gain on the sale. The change-in-interest gain and the realized gain from the share sale, totaling approximately $23.8 million, were recorded in "Other income (expense), net" for the three months ended January 31, 2014.
	The Company received the sales proceeds in April 2014. As of April 30, 2014, the Company owned 13.3% of WLCSP.
	The foreign exchange effects on WLCSP's net assets are recorded as part of the Company's cumulative translation adjustment in "Accumulated other comprehensive income." The total gain of $23.8 million from WLCSP's IPO included a pro rata release of approximately $1.0 million of the cumulative translation adjustment from "Accumulated other comprehensive income."
	The Company received the following dividend payments from WLCSP during the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Dividend payments received from WLCSP	$	830	$	890	$	852
	In April 2014, the Company recorded a dividend receivable of approximately $0.7 million when WLCSP declared its calendar 2013 dividend.
	The Company accounts for its investment in WLCSP under the equity method. The following table presents equity income recorded by the Company for the periods indicated in "Equity in earnings of investee," consisting of its portion of the net income recorded by WLCSP during the periods presented, and equity method investment adjustments (in thousands). For fiscal 2014, the Company only included in "Equity in earnings of investee" its share of WLCSP's earnings from May 1, 2013 to March 31, 2014. (See Note 1.)
		Year Ended April 30,
		2014		2013		2012
	Equity income	$	4,009	$	3,832	$	3,066
	XinTec, Inc.
	XinTec, Inc. ("XinTec") is a Taiwan-based supplier of chip scale packaging services. The Company first made investments in XinTec in April 2003, for $2.8 million. As of April 30, 2014, the Company's direct ownership percentage in XinTec was 4.2%. Separately, VisEra Cayman owns a 15.8% interest in XinTec. Consequently, the Company's beneficial ownership percentage in XinTec was approximately 11.9%. The Company accounts for XinTec as a cost method investment.
	Tong Hsing Electronic Industries, Limited
	Tong Hsing Electronic Industries, Limited ("Tong Hsing") is a Taiwan-based public company principally engaged in the development and production of microelectronic packaging technologies. In December 2009, the Company obtained 0.8% of the outstanding shares of common stock of Tong Hsing, or 996,250 shares, when Tong Hsing acquired ImPac Technology Co., Ltd. ("ImPac") in a stock-for-stock exchange. Prior to the exchange, the Company owned 25.7% of ImPac. As a result of the exchange, the Company recorded a gain of approximately $2.2 million in "Other income (expense), net," which was the difference between the fair value of the Tong Hsing's shares the Company received on December 31, 2009, and the carrying value of the Company's investment in ImPac on the same day. In June 2010 and June 2011 the Company participated in Tong Hsing's secondary offering and purchased 95,570 and 115,481 shares, respectively, for corresponding amounts of approximately $282,000 and $421,000. In October 2013, the Company sold its entire investment in Tong Hsing, which amounted to an ownership percentage in Tong Hsing of approximately 0.7%. With the sale, the Company recorded a gain of approximately $2.0 million in "Other income (expense), net" during the three months ended October 31, 2013.
	Prior to stock sale in October 2013, the Company reported its investment in Tong Hsing on a mark-to-market basis, net of deferred taxes, since the shares of Tong Hsing are traded on the Taiwan Stock Exchange and the share price is readily determinable. For the periods indicated, the Company recorded the following unrealized holding gains (losses) in "Accumulated other comprehensive income" (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Unrealized holding gains (losses)	$	566	$	859	$	(328	)
	Phostek, Inc.
	Phostek, Inc. ("Phostek") is a privately held company that develops and manufactures light emitting diodes in Taiwan. The Company made an investment in Phostek in February 2012, for a total of $2.0 million in cash. The Company does not have the ability to exercise significant influence over the operating and financial policies of Phostek. As a result, the Company accounts for this investment using the cost method.
	In July 2013, based on a combination of factors, including Phostek's accumulated losses and its decision to not pursue any additional funding to support its original business plans, the Company performed an impairment analysis and concluded that the investment in Phostek should be impaired in its entirety. Consequently, the Company recorded an impairment charge of $2.0 million in "Other income (expense), net" during the three months ended July 31, 2013.
	The following table presents the summary financial information of VisEra and WLCSP, as derived from their respective financial statements for the periods indicated. The summary financial information of WLCSP reflects the information as used by the Company for its equity method of accounting for WLCSP in fiscal 2014. (See Note 1.) Each investee's financial information was prepared under GAAP (in thousands):
	VisEra Technologies Company, Ltd.
		Year Ended April 30,
		2014		2013		2012
	Operating data:
	Revenues	$	131,850	$	169,969	$	125,777
	Gross profit		50,426		58,531		32,607
	Income from operations		40,312		47,512		48,818
	Net income	$	32,121	$	31,921	$	32,482
		April 30,
		2014		2013
	Balance sheet data:
	Current assets	$	189,399	$	168,343
	Long-term assets		112,956		132,633
Current liabilities		38,086		68,854
Long-term liabilities	$	—	$	—
China WLCSP Limited
			Year Ended
	11 Months		April 30,
	Ended
	March 31,
	2014		2013		2012
Operating data:
Revenues	$	75,480	$	57,340	$	47,700
Gross profit		40,909		31,348		24,854
Income from operations		26,428		23,742		18,458
Net income	$	23,055	$	20,520	$	16,638
	March 31,		April 30,
	2014		2013
Balance sheet data:
Current assets	$	221,547	$	52,985
Long-term assets		134,482		81,733
Current liabilities		96,570		12,204
Long-term liabilities	$	3	$	3
The Company's share of undistributed earnings of investees accounted for by the equity method as of the dates indicated were as follows (in thousands):
	April 30,
	2014		2013
Undistributed earnings of investees	$	66,772	$	49,830

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Apr. 30, 2014
Goodwill and Intangible Assets	'
Goodwill and Intangible Assets	'
	Note 6—Goodwill and Intangible Assets
	Goodwill
	There was no change to the carrying value of the Company's goodwill during fiscal 2014 and 2013 as noted below (in thousands):
		Year Ended April 30,
		2014		2013
	Beginning balance, May 1	$	10,227	$	10,227
	Changes to carrying value		—		—
	Ending balance, April 30	$	10,227	$	10,227
	Intangible Assets
	In January 2014, the Company entered into a license agreement with the California Institute of Technology ("Caltech") pursuant to which the Company acquired a license to various image sensor patents held by Caltech in a cash transaction that totaled approximately $25.4 million, and the payment schedule of which has a net present value of approximately $24.6 million. As part of the license agreement, the parties agreed to settle and dismiss the outstanding claims between them. As a result, during the three months ended January 31, 2014, the Company recorded $2.7 million to "Cost of revenues," representing the cumulative cost related to prior years under the relief-from-royalty method. In addition, the Company recorded the remaining $21.9 million as addition to "Patents and licenses," which the Company will amortize over a period of nine years, and the amortization expenses will be recorded in "Cost of revenues."
	Intangible assets as of the dates indicated consisted of the following (in thousands):
		April 30, 2014
		Cost		Accumulated		Net Book
				Amortization		Value
	Acquired patent portfolio	$	65,000	$	28,631	$	36,369
	Core technology		36,100		27,980		8,120
	Patents and licenses		36,066		14,438		21,628
	Trademarks and tradenames		1,400		1,400		—
	Customer relationships		340		240		100
	Intangible assets, net	$	138,906	$	72,689	$	66,217
		April 30, 2013
		Cost		Accumulated		Net Book
				Amortization		Value
	Acquired patent portfolio	$	65,000	$	19,345	$	45,655
	Core technology		36,100		25,649		10,451
	Patents and licenses		14,160		13,596		564
	Trademarks and tradenames		1,400		1,400		—
	Customer relationships		340		206		134
	Intangible assets, net	$	117,000	$	60,196	$	56,804
	The following table presents the amortization of intangibles recorded by the Company for the periods indicated (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Amortization of intangible assets	$	3,207	$	3,638	$	2,778
	Amortization of acquired patent portfolio	$	9,286	$	9,286	$	9,286
	The total expected future annual amortization of these intangible assets is as follows (in thousands):
	Years Ending April 30,
	2015	$	13,929
	2016		13,753
	2017		13,627
	2018		12,546
	2019		3,234
	Thereafter		9,128
	Total	$	66,217

Borrowing_Arrangements_and_Rel

Borrowing Arrangements and Related Derivative Instruments	12 Months Ended
	Apr. 30, 2014
Borrowing Arrangements and Related Derivative Instruments	'
Borrowing Arrangements and Related Derivative Instruments	'
	Note 7—Borrowing Arrangements and Related Derivative Instruments
	The following table sets forth the Company's debt as of the dates indicated (in thousands):
		April 30,
		2014			2013
	Mortgage loan	$	23,653		$	24,207
	Construction loan		12,179			15,271
			35,832			39,478
	Less: amount due within one year		(3,802	)		(3,769	)
	Non-current portion of long-term debt	$	32,030		$	35,709
	As of April 30, 2014, aggregate debt maturities were as follows (in thousands):
	Years Ending April 30,	Mortgage			Construction			Total
		Loan			Loan
	2015	$	554		$	3,248		$	3,802
	2016		554			6,495			7,049
	2017		22,545			2,436			24,981
	Thereafter		—			—			—
	Total	$	23,653		$	12,179		$	35,832
	Mortgage Loan and Term Loan
	On March 16, 2007, the Company entered into a Loan and Security Agreement with a domestic bank for the purchase of a complex of four buildings located in Santa Clara, California (the "Santa Clara Property"). The Loan and Security Agreement provides for a mortgage loan in the principal amount of $27.9 million (the "Mortgage Loan") and a secured line of credit with an aggregate maximum principal amount of up to $12.0 million (the "Term Loan").The Company drew down the entire $12.0 million under the Term Loan by July 2008, and paid it off by July 31, 2012.
	The Mortgage Loan matures on March 31, 2017, and borrowings under the Mortgage Loan accrue interest at the London Interbank Borrowing Rate ("LIBOR") plus 90 basis points. The Company was in compliance with the financial covenants of the Loan and Security Agreement as of April 30, 2014.
	Interest rates under the Mortgage Loan for the dates indicated are set forth below:
		April 30,
		2014			2013
	Mortgage Loan		1.1	%		1.1	%
	In conjunction with the Mortgage Loan, the Company entered into an interest rate swap with the same bank to effectively convert the variable interest rate described above to a fixed rate. The swap is for a period of ten years, and the notional amount of the swap approximates the principal outstanding under the Mortgage Loan. The Company is the fixed rate payer under the swap and the rate is fixed at 5.3% per annum and the effective rate on the Mortgage Loan is fixed at approximately 6.2%. The Company had a second interest rate swap associated with the Term Loan that fixed the Term Loan's interest rate at 4.3% per annum and fixed the effective rate at approximately 5.5%. The second swap expired in July 2012 when the Term Loan matured and was paid off.
	Construction Loan
	On August 3, 2009, OmniVision Technologies (Shanghai) Co., Ltd., a wholly-owned subsidiary of the Company, entered into a Fixed Assets Loan Agreement with a bank in China (the "Construction Loan"). The purpose of the Construction Loan was to construct a research center for the Company in Pudong Development Zone, the Zhang Jiang Science Park in Shanghai, China. During the second quarter of fiscal 2011, the Company completed the construction of the research center. As of April 30, 2014, the total amount outstanding under the Construction Loan was Chinese Yuan 75.0 million, or approximately $12.2 million. The Construction Loan matures on June 30, 2016.
	The interest rate under the Construction Loan is based on an indicative rate as published by the Chinese government, and will be adjusted only at the anniversary of each drawdown. The interest rate under the Construction Loan was 5.9% at April 30, 2014 and 2013, respectively. The Company was in compliance with the financial covenants of the Fixed Assets Loan Agreement as of April 30, 2014.
	Derivative Instruments and Hedging Activities
	As indicated above, the Company entered into two separate interest rate swaps in connection with the Mortgage Loan and the Term Loan. The interest rate swap related to the Mortgage Loan is scheduled to expire in March 2017, while the interest rate swap related to the Term Loan expired on July 31, 2012. The swaps were set up to reduce the effect of interest rate variability on the two loans' interest payments. During the set up, the Company did not designate the two interest rate swaps as hedging instruments. Consequently, the Company had to remeasure the two interest rate swaps at fair value at each subsequent balance sheet date, and immediately recognize any changes to the fair values in earnings. On the consolidated balance sheet, the Company records the swaps as either assets or liabilities, depending on whether the fair value represents net gains or net losses. (See Note 11.)
	The table below presents the location of the swaps on the Consolidated Statements of Income and Consolidated Balance Sheets, and the related effects on the Company's results of operations and financial positions for the periods indicated (in thousands):
		Year Ended April 30,
		2014			2013			2012
	Location of amounts recognized in Consolidated Statements of Income and amount of gains (losses):
	Other income (expense), net	$	1,204		$	625		$	(880	)
		April 30,
		2014			2013
	Location of amounts on Consolidated Balance Sheets and fair values:
	Other long-term liabilities	$	2,980		$	4,184

Income_Taxes

Income Taxes	12 Months Ended
	Apr. 30, 2014
Income Taxes	'
Income Taxes	'
	Note 8—Income Taxes
	The provision for income taxes consists of the following (in thousands):
		Year Ended April 30,
		2014			2013			2012
	Current:
	Federal	$	5,802		$	7,746		$	3,068
	State		17			16			16
	Foreign		(4,315	)		3,863			808
	Total current		1,504			11,625			3,892
	Deferred:
	Federal		6,066			(2,261	)		3,356
	State		1,832			(837	)		(449	)
	Foreign		530			(1,265	)		—
	Total deferred		8,428			(4,363	)		2,907
	Total provision	$	9,932		$	7,262		$	6,799
	Income (loss) before provision for income taxes consisted of (in thousands):
		Year Ended April 30,
		2014			2013			2012
	United States	$	(16,581	)	$	(20,996	)	$	2,280
	International		121,510			71,160			70,368
	Total	$	104,929		$	50,164		$	72,648
	The provision for income taxes differs from the amount computed by applying the U.S. federal income tax rate of 35.0% to "Income before income taxes" as a result of the following (in thousands):
		Year Ended April 30,
		2014			2013			2012
	Provision based on statutory federal income tax rate	$	36,725		$	17,557		$	25,426
	State income tax expense (benefit), net of federal tax benefit		1,849			(868	)		(481	)
	Foreign rate differential		(32,481	)		(14,843	)		(21,349	)
	Non-deductible stock-based compensation		6,678			7,412			5,583
	Tax credits		(3,691	)		(3,409	)		(2,979	)
	Prior year adjustment		—			1,184			—
	Other		852			229			599
	Tax provision	$	9,932		$	7,262		$	6,799
	The effective tax rates for fiscal 2014, 2013 and 2012 are less than the combined U.S. federal and state statutory rate of approximately 40%, principally because the Company earns a significant portion of its profits in jurisdictions where tax rates are lower than the combined U.S. federal and state statutory rate. In fiscal 2014, the Company included in the amount of foreign rate differential a $8.9 million reduction of unrecognized tax benefits, including the related interest and penalties, due to lapses of applicable statute of limitations.
	The components of net deferred tax assets included in the consolidated balance sheets for the fiscal years indicated were (in thousands):
		April 30,
		2014			2013
	Deferred tax assets:
	Tax credits	$	28,589		$	23,832
	Net operating loss		3,099			1,612
	Stock-based compensation expenses		7,406			7,230
	Unrealized loss on interest rate swap		1,044			1,694
	Fixed assets		533			1,355
	Accruals, reserves and other		6,174			6,105
	Gross deferred tax assets		46,845			41,828
	Valuation allowance		(17,326	)		(12,116	)
	Deferred tax assets		29,519			29,712
	Deferred tax liabilities:
	Undistributed earnings of non-US equity investees not permanently reinvested		(25,771	)		(17,735	)
	Other		(2,122	)		(1,698	)
	Deferred tax liabilities		(27,893	)		(19,433	)
	Net deferred tax assets	$	1,626		$	10,279
	The Company has elected to derecognize both the gross deferred tax assets and the offsetting valuation allowance pertaining to net operating loss and tax credit carryforwards that represent excess tax benefits from stock-based awards. Recognition of a deferred tax asset for excess tax benefits due to stock-based compensation deductions that have not yet been realized through a reduction in income taxes payable is prohibited. Such unrecognized deferred tax benefits totaled $18.7 million and $21.1 million as of April 30, 2014 and 2013, respectively, and, if and when realized through a reduction in income taxes payable, will be accounted for as a credit to additional paid-in capital.
	Management regularly assesses the realizability of deferred tax assets recorded based upon the weight of available evidence, including such factors as recent earnings history and expected future taxable income on a jurisdiction by jurisdiction basis. Deferred tax assets in the amount of $17.3 million and $12.1 million at April 30, 2014 and 2013, respectively, primarily pertain to California research and development tax credit carryovers that the Company believes it is not more-likely-than-not that the Company will realize; therefore, a valuation allowance has been established against such deferred tax assets. In the future, if the credit is utilized and the valuation allowance is released, the release of valuation allowance will be accounted for as a reduction of the income tax expense in the year such event occurs.
	As of April 30, 2014, the Company has U.S. federal and California net operating loss ("NOL") carryforwards of $3.4 million and $31.7 million, respectively. If not utilized, the U.S. federal NOL will begin to expire in fiscal 2029 and the California NOL will begin to expire in fiscal 2032. The Company has U.S. federal and California research and development tax credits of $31.5 million and $35.3 million, respectively. If not utilized, the U.S. federal research and development tax credits will begin to expire in fiscal 2025 and the California research and development tax credits will be carried over indefinitely.
	The Company has not provided U.S. federal and state income taxes, as well as foreign withholding taxes, on approximately $496.2 million of undistributed earnings for certain non-U.S. subsidiaries, because such earnings are intended to be indefinitely reinvested. Determination of the amount of unrecognized deferred tax liability for temporary differences related to investment in these non-U.S. subsidiaries that are essentially permanent in duration is not practicable.
	The Company is subject to income taxes in the U.S. and numerous foreign jurisdictions. Significant judgment is required in evaluating the tax positions and determining the provision for income taxes. During the ordinary course of business, there are many transactions and calculations for which the ultimate tax determination is uncertain. The Company establishes reserves for tax-related uncertainties based on estimates of whether, and the extent to which, additional taxes will be due. These reserves are established when the Company believes that certain positions might be challenged despite the Company's belief that the tax return positions are fully supportable. The Company adjusts these reserves in light of changing facts and circumstances, such as lapses of the relevant statute of limitations. The provision for income taxes includes the impact of reserve provisions and changes to reserves that are considered appropriate.
	A reconciliation of the beginning balance and the ending balance of gross unrecognized tax benefits, excluding interest and penalties, is as follows (in thousands):
		April 30,
		2014			2013			2012
	Balance at beginning of fiscal year	$	90,561		$	87,433		$	85,734
	Increases in balances related to tax positions taken during current year		4,345			6,288			4,536
	Decreases as a result of lapses of the applicable statute of limitations		(8,507	)		(3,123	)		(2,667	)
	Increases in balances related to tax positions taken during prior years		1,363			422			89
Decreases in balances related to tax positions taken during prior years		(3,531	)		(459	)		(259	)
Balance at end of fiscal year	$	84,231		$	90,561		$	87,433
A reconciliation of the gross unrecognized tax benefits, including interest and penalties, as presented on the Consolidated Balance Sheets is as follows (in thousands):
	April 30,
	2014			2013
Recorded as an increase in deferred tax liabilities—non-current	$	14,424		$	—
Recorded as a decrease in deferred tax assets—non-current		—			15,973
Long-term income taxes payable		86,498			90,777
Balance at end of fiscal year	$	100,922		$	106,750
The Company includes interest, penalties and foreign exchange gain or loss related to unrecognized tax benefits within the provision for income taxes in the Consolidated Statements of Income. The Company recognized the following net amounts of interest and penalties and the related foreign exchange gain or loss for the periods presented (in thousands):
	Year Ended April 30,
	2014			2013			2012
Recognized interest and penalties, net	$	502		$	1,449		$	865
Included in the fiscal 2014 and 2013 net amounts of interest and penalties are benefits of $394,000 and $463,000, respectively, primarily due to the reversal of accrued interest and penalties related to the reductions to unrecognized tax benefits as a result of lapses of the statute of limitations.
The Company had cumulatively accrued the following amounts for potential interest and penalties as of the dates indicated (in thousands):
	April 30,
	2014			2013
Balance at end of fiscal year	$	16,691		$	16,189
The total amount of unrecognized tax benefits, net of federal benefit for the deduction of such items as interest that, if recognized, would affect the effective tax rate is $95.4 million as of April 30, 2014. One or more of these unrecognized tax benefits could be subject to a valuation allowance if and when recognized in a future period, which could impact the timing of any related effective tax rate benefit.
The Company files U.S. federal and state, as well as foreign, tax returns. For such returns, the Company is generally no longer subject to tax examinations for years prior to fiscal 2004. The Company is currently under tax examination in a foreign jurisdiction starting from the fiscal year ended April 30, 2004. It is possible that this tax examination may be concluded in the next 12 months. The Company will continue to review its tax positions and provide for, or reverse, unrecognized tax benefits as issues arise. As of April 30, 2014, the Company anticipates that the balance of gross unrecognized tax benefits will decrease by $15.1 million due to lapses of the applicable statutes of limitations in certain jurisdictions over the next 12 months.
In fiscal 2013, the Company obtained a partial tax holiday from the Singapore Economic Development Board, an agency of the Government of Singapore. This partial tax holiday allows for reduced rates of Singapore income tax on certain classes of income generated from the Company's business operations in Singapore, from September 1, 2012 through August 31, 2022. In order to retain these tax benefits in Singapore, the Company must meet several requirements as to capital and business spending, headcount and activities. For fiscal 2014, the effect of the Singapore partial tax holiday, in the aggregate, was reducing the overall provision for income taxes from what it otherwise would have been by $22.6 million, thus increasing diluted net income per share by $0.40.

Net_Income_Per_Share

Net Income Per Share	12 Months Ended
	Apr. 30, 2014
Net Income Per Share	'
Net Income Per Share	'
	Note 9—Net Income Per Share
	Basic net income per share is computed by dividing net income attributable to OmniVision by the weighted average number of common shares outstanding during the period.
	Diluted net income per share is computed according to the treasury stock method using the weighted average number of common and potentially dilutive common shares outstanding during the period. Potentially dilutive common shares represent the effect of stock options, purchases via employee stock purchase plans and restricted stock units. The following table sets forth the number of stock options that were excluded from the calculation of diluted net income per share because they were antidilutive for the periods indicated:
		Year Ended April 30,
		2014		2013		2012
	Antidilutive common stock subject to outstanding options		2,510,000		2,957,000		1,222,000
	The following table sets forth the computation of basic and diluted earnings per share for the periods indicated (in thousands, except per share data):
		Year Ended April 30,
		2014		2013		2012
	Basic:
	Numerator:
	Net income	$	94,997	$	42,902	$	65,849
	Denominator:
	Weighted average common shares for net income per share		55,537		53,529		56,666
	Basic net income per share	$	1.71	$	0.8	$	1.16
	Diluted:
	Numerator:
	Net income	$	94,997	$	42,902	$	65,849
	Denominator:
	Denominator for basic net income per share		55,537		53,529		56,666
	Weighted average effect of dilutive securities:
	Stock options, restricted stock units and employee stock purchase plan shares		506		142		1,567
	Weighted average common shares for diluted net income per share		56,043		53,671		58,233
	Diluted net income per share	$	1.7	$	0.8	$	1.13

Comprehensive_Income

Comprehensive Income	12 Months Ended
	Apr. 30, 2014
Comprehensive Income	'
Comprehensive Income	'
	Note 10—Comprehensive Income
	The following table presents the components of other comprehensive income and related tax effects for the periods indicated (in thousands):
		Year Ended April 30, 2014									Year Ended April 30, 2013								Year Ended April 30, 2012
		Before			Tax			Net of			Before			Tax			Net of		Before			Tax			Net of
		Tax						Tax			Tax						Tax		Tax						Tax
	Translation gains	$	53		$	(18	)	$	35		$	431		$	(151	)	$	280	$	2,893		$	(1,010	)	$	1,883
	Reclassification adjustments for gains on sale of WLCSP		(1,023	)		358			(665	)		—			—			—		—			—			—
	Unrealized gains (losses) on available-for-sale securities		528			(185	)		343			839			(148	)		691		(638	)		299			(339	)
	Reclassification adjustments for losses on available-for-sale securities		(1,641	)		354			(1,287	)		18			(7	)		11		—			—			—
	Total other comprehensive income	$	(2,083	)	$	509		$	(1,574	)	$	1,288		$	(306	)	$	982	$	2,255		$	(711	)	$	1,544
	The following table presents the components of, and the changes in, accumulated other comprehensive income for the periods indicated (in thousands):
		Balance at			Other			Amounts			Related Tax			Balance at
		May 1, 2012			Comprehensive			Reclassified out			Effects			April 30,
					Income (Loss),			of Accumulated						2013
					Before Tax			Other
								Comprehensive
								Income
	Accumulated translation gains	$	2,756		$	431		$	—		$	(151	)	$	3,036
	Accumulated unrealized gains (losses) on available-for-sale securities, net		214			857			—			(155	)		916
	Total accumulated other comprehensive income	$	2,970		$	1,288		$	—		$	(306	)	$	3,952
		Balance at			Other			Amounts			Related Tax			Balance at
		May 1, 2013			Comprehensive			Reclassified out			Effects			April 30,
					Income (Loss),			of Accumulated						2014
					Before Tax			Other
								Comprehensive
								Income
	Accumulated translation gains	$	3,036		$	53		$	(1,023	)	$	340		$	2,406
	Accumulated unrealized gains (losses) on available-for-sale securities, net		916			528			(1,641	)		169			(28	)
	Total accumulated other comprehensive income	$	3,952		$	581		$	(2,664	)	$	509		$	2,378
	The following table sets forth the amounts reclassified out of Accumulated Other Comprehensive Income into the Consolidated Statements of Income and the associated presentation location, for the periods indicated (in thousands):
				Year Ended April 30,
	Comprehensive Income Components	Location		2014			2013			2012
	Accumulated translation gains	Other income (expense), net		$	(1,023	)	$	—		$	—
	Accumulated unrealized gains (losses) on available-for-sale securities, net	Other income (expense), net			(1,641	)		—			—
		Total amounts reclassified out of Accumulated Other Comprehensive Income		$	(2,664	)	$	—		$	—

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Apr. 30, 2014
Fair Value Measurements	'
Fair Value Measurements	'
	Note 11—Fair Value Measurements
	The authoritative guidance for fair value measurements specifies a hierarchy of valuation techniques based upon whether the inputs to those valuation techniques reflect assumptions other market participants would use based upon market data obtained from independent sources (observable inputs) or reflect the Company's own assumption of market participant valuation (unobservable inputs). The fair value hierarchy consists of the following three levels:
	•
	Level 1—Inputs are quoted prices in active markets for identical assets or liabilities.
	•
	Level 2—Inputs are quoted prices for similar assets or liabilities in an active market, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable and market-corroborated inputs which are derived principally from or corroborated by observable market data.
	•
	Level 3—Inputs are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable.
	Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were comprised of the following types of instruments as of the date indicated (in thousands):
		April 30, 2014
		Total			Level 1		Level 2			Level 3
	Money market funds	$	57,207		$	57,207	$	—		$	—
	U.S. government debt securities and municipal bonds		17,834			—		17,834			—
	Corporate debt securities/commercial paper		180,764			—		180,764			—
	Total assets	$	255,805		$	57,207	$	198,598		$	—
	Interest rate swap	$	(2,980	)	$	—	$	(2,980	)	$	—
	Total liabilities	$	(2,980	)	$	—	$	(2,980	)	$	—
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were presented on the Company's Consolidated Balance Sheets as of the date indicated (in thousands):
		April 30, 2014
		Total			Level 1		Level 2			Level 3
	Cash equivalents	$	102,812		$	57,207	$	45,605		$	—
	Short-term investments		152,993			—		152,993			—
	Total assets	$	255,805		$	57,207	$	198,598		$	—
	Interest rate swap	$	(2,980	)	$	—	$	(2,980	)	$	—
	Total liabilities	$	(2,980	)	$	—	$	(2,980	)	$	—
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were comprised of the following types of instruments as of the date indicated (in thousands):
		April 30, 2013
		Total			Level 1		Level 2			Level 3
	Money market funds	$	44,409		$	44,409	$	—		$	—
	U.S. government debt securities and municipal bonds		1,707			—		1,707			—
	Corporate debt securities/commercial paper		20,457			—		20,457			—
	Equity investment in Tong Hsing		5,313			5,313		—			—
	Total assets	$	71,886		$	49,722	$	22,164		$	—
	Interest rate swaps	$	(4,184	)	$	—	$	(4,184	)	$	—
	Total liabilities	$	(4,184	)	$	—	$	(4,184	)	$	—
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were presented on the Company's Consolidated Balance Sheets as of the date indicated (in thousands):
		April 30, 2013
		Total			Level 1		Level 2			Level 3
	Cash equivalents	$	44,409		$	44,409	$	—		$	—
	Short-term investments		22,164			—		22,164			—
	Long-term investments		5,313			5,313		—			—
	Total assets	$	71,886		$	49,722	$	22,164		$	—
	Interest rate swaps	$	(4,184	)	$	—	$	(4,184	)	$	—
	Total liabilities	$	(4,184	)	$	—	$	(4,184	)	$	—
	For the Company's interest rate swap, the Company obtains fair value quotes from the issuing bank and assesses the quotes for reasonableness by comparing them to the present values of expected cash flows. The present value approach is based on observable market interest rate curves that are commensurate with the terms of the interest rate swap. The carrying value represents the fair value of the swap, as adjusted for any non-performance risk associated with the Company.
	Due to their short maturities, the reported amounts of the Company's financial instruments, including cash equivalents, short-term investments, accounts receivable, accounts payable and other current liabilities approximate their fair values.
	For its investment in WLCSP, the Company uses the equity method of accounting. (See Note 5.) As of April 30, 2014, using the per share closing price of the stock of $5.50 on the Shanghai Stock Exchange, the aggregate fair value of the Company's investment in WLCSP totaled approximately $166.5 million.
	The Mortgage Loan and the Construction Loan are recorded at cost. Their book values, however, approximate fair values as the underlying interest rates are based on risk-adjusted market rates; they are categorized as Level 2 for purposes of the fair value measurement hierarchy.

Common_Stock_and_Treasury_Stoc

Common Stock and Treasury Stock	12 Months Ended
	Apr. 30, 2014
Common Stock and Treasury Stock	'
Common Stock and Treasury Stock	'
	Note 12—Common Stock and Treasury Stock
	The Company is authorized to issue up to 100,000,000 shares of common stock. As of April 30, 2014 and 2013 56,081,586 and 53,975,195 shares were outstanding, respectively. As of April 30, 2014 and 2013, 20,599,187 shares were held as treasury stock. In addition, as of April 30, 2014, 13,655,166 and 2,543,504 shares of common stock have been reserved for issuance under the Company's employee equity incentive plans and employee stock purchase plan, respectively.
	In November 2011, the Company's board of directors approved a new stock repurchase program, authorizing the repurchase in an open-market of up to an aggregate of $100.0 million of the Company's common stock. By December 2011, the Company had repurchased 8,058,187 shares of its common stock under this open-market program, for an aggregate cost of approximately $100.0 million.

Employee_Stock_Purchase_Equity

Employee Stock Purchase, Equity Incentive and Stock Option Plans	12 Months Ended
	Apr. 30, 2014
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'
	Note 13—Employee Stock Purchase, Equity Incentive and Stock Option Plans
	The Company's equity incentive and stock-based compensation plans as of April 30, 2014 are summarized as follows (in thousands):
	Name of Plan	Shares			Shares			Options			Restricted
		Authorized			Available			Outstanding			Stock Units
					for Grant						Outstanding
	2000 Stock Plan		—			—			1,358			—
	2000 Director Option Plan		—			—			88			—
	2007 Equity Incentive Plan		18,100			6,921			2,557			2,732
	Total		18,100			6,921			4,003			2,732
	2007 Equity Incentive Plan
	In September 2007, on the recommendation of the Company's board of directors, the stockholders of the Company approved the 2007 Equity Incentive Plan (the "2007 Plan"). The 2007 Plan replaced the Company's 2000 Stock Plan. The Company has initially reserved 6,000,000 shares of common stock for issuance under the 2007 Plan. The 2007 Plan provides for the grant of the following types of incentive awards: (i) stock options; (ii) stock appreciation rights; (iii) restricted stock; (iv) restricted stock units; (v) performance shares and performance units; and (vi) other stock or cash awards. In general, stock option and stock appreciation right awards under the 2007 Plan will be granted at a price not less than 100% of the fair market value of the Company's common stock on the date of grant. With the approval of the Company's stockholders in September 2009, the Company modified certain terms of the 2007 Plan. Under the modified 2007 Plan, the Company's stock option awards generally have a maximum contractual term of seven years and vest over four years. Restricted stock units granted under the 2007 Plan generally vest over three years. The 2007 Plan also covers grants of equity-based compensation to the Company's directors. In September 2011 and 2013, the stockholders of the Company approved amendments to the 2007 Plan, increasing the shares available for issuance under the 2007 Plan by 7,200,000 and 4,900,000 shares, respectively. As of April 30, 2014, options to purchase approximately 2,557,000 shares of common stock were outstanding under the 2007 Plan.
	2000 Stock Plan
	In February 2000, the Company adopted the 2000 Stock Plan under which 6,000,000 shares of common stock were initially reserved for issuance together with an annual increase in the number of shares reserved thereunder beginning on the first day of the Company's fiscal year, commencing May 1, 2002, in an amount equal to the lesser of: 3,000,000 shares, or 6% of outstanding shares of common stock on the last day of the prior fiscal year, or an amount determined by the Company's board of directors. The 2000 Stock Plan provided for grants of incentive stock options to its employees including officers and employees, directors and nonstatutory stock options to its consultants including nonemployee directors. Incentive stock options were granted at a price not less than 100% of the fair market value of the Company's common stock and at a price not less than 110% of the fair market value for grants to any person who owned more than 10% of the voting power of all classes of stock on the date of grant. Nonstatutory stock options were granted at a price not less than 85.0% of the fair market value of the common stock and at a price not less than 110% of the fair market value for grants to a person who owned more than 10% of the voting power of all classes of stock on the date of the grant. Options granted under the 2000 Stock Plan have been at fair market value on the date of the grant and generally vest over four years and are exercisable up to ten years (five years for grants to any person who owned more than 10% of the voting power of all classes of stock on the date of the grant). With the adoption of the 2007 Plan, no additional equity awards will be issued under the 2000 Stock Plan. As of April 30, 2014, options to purchase approximately 1,358,000 shares of common stock were outstanding under the 2000 Stock Plan.
	2000 Director Option Plan
	The 2000 Director Option Plan was adopted by the board of directors in February 2000 and approved by the shareholders in March 2000. Under this plan 500,000 shares of common stock were initially reserved for issuance together with an annual increase in the number of shares reserved thereunder beginning on the first day of the Company's fiscal year commencing May 1, 2002 equal to the lesser of 150,000 shares, or 0.25% of the outstanding shares of the common stock on the last day of the prior fiscal year, or an amount determined by the board of directors. The 2000 Director Option Plan provided for an initial grant to the nonemployee director to purchase 40,000 shares of common stock. Subsequent to the initial grants, each nonemployee director was granted an option to purchase 20,000 shares of common stock at the next meeting of the board of directors following the annual meeting of stockholders, if on the date of the annual meeting the director had served on the board of directors for not less than six months. The contractual term of options granted under the 2000 Director Option Plan was ten years, but the options expire three months following the termination of the optionee's status as a director or twelve months if the termination is due to death or disability. The initial 40,000 share grants were exercisable at a rate of one-fourth of the shares on the first anniversary of the grant date and at a rate of 1/16th of the shares per quarter thereafter. The subsequent 20,000 share grants were exercisable at the rate of 1/16th of the shares per quarter. The exercise price of all of these options is 100% of the fair market value of the common stock on the date of grant. In November 2007, the Company's board of directors approved the termination of the Company's 2000 Director Option Plan. The 2007 Plan will also cover all future grants of equity-based compensation to directors. As of April 30, 2014, options to purchase approximately 88,000 shares of common stock were outstanding under the 2000 Director Option Plan.
	2009 Employee Stock Purchase Plan
	The 2009 Employee Stock Purchase Plan (the "2009 Purchase Plan") was adopted by the board of directors in July 2009 and was approved by the stockholders of the Company in September 2009. The 2009 Purchase Plan replaced the Company's 2000 Employee Stock Purchase Plan in December 2009. The board of directors has initially reserved a total of 2,500,000 shares of common stock for issuance under the 2009 Purchase Plan. Each offering period under the 2009 Purchase Plan will have a duration of approximately 24 months, commencing on the first trading day on or after June 1 and December 1 of each year and terminating on the last trading day in the period ending 24 months later. Each offering period will generally consist of four six-month purchase periods in which shares may be purchased on a participant's behalf. The purchase price will be 85% of the lesser of the fair market value of the common stock on the first trading day of the offering period or on the last day of the purchase period. If the fair market value of the common stock on the last day of the purchase period is lower than the fair market value of the common stock on the enrollment date of the associated offering period, all participants in such offering period will automatically be rolled over to the immediately following offering period. Employees may end their participation in an offering period at any time, and their participation ends automatically on termination of employment with the Company. The first offering period under the 2009 Purchase Plan began on December 1, 2009. In September 2013, the stockholders of the Company approved an amendment to the 2009 Purchase Plan, increasing the number of shares reserved for issuance by 2,500,000 shares. As of April 30, 2014, approximately 2,456,496 shares had been purchased under the 2009 Purchase Plan.
	Stock-Based Compensation Award Activity
	The following table summarizes the equity award activities under the 2000 Stock Plan, the 2000 Director Option Plan and the 2007 Plan, for the three fiscal years ended April 30, 2014:
					Options Outstanding						Restricted			Restricted
											Stock Units			Stock Units
											Outstanding
		Shares			Number of			Weighted			Number of			Weighted
		Available			Shares			Average			Shares			Average
		For						Exercise						Grant Date
		Grant						Price						Fair Market
								Per Share						Value Per
														Share
		(in thousands)			(in thousands)						(in thousands)
	Balance at May 01, 2012		2,717			3,936		$	16.31			2,005		$	16.81
	2007 Plan share increased		7,200			—			—			—			—
	Stock options granted		(600	)		600			34.65			—			—
	Stock options exercised		—			(885	)		15.41			—			—
	Stock options expired or forfeited		28			(81	)		20.42			—			—
	Restricted stock units granted(1)		(2,088	)		—			—			1,305			32.27
	Restricted stock units vested(1)		—			—			—			(1,116	)		14.84
	Restricted stock units expired or forfeited(1)		231			—			—			(141	)		23.71
	Balance at April 30, 2012		7,488			3,570			19.53			2,053			27.24
	Stock options granted		(644	)		644			13.53			—			—
	Stock options exercised		—			(137	)		7.95			—			—
	Stock options expired or forfeited		2			(83	)		20.8			—			—
	Restricted stock units granted(1)		(2,446	)		—			—			1,528			13.39
	Restricted stock units vested(1)		—			—			—			(903	)		24.39
	Restricted stock units expired or forfeited(1)		359			—			—			(224	)		20.26
	Balance at April 30, 2013		4,759			3,994			18.93			2,454			20.3
	2007 Plan amendment		4,900			—			—			—			—
	Stock options granted		(692	)		692			18.47			—			—
	Stock options exercised		—			(465	)		14.66			—			—
	Stock options expired or forfeited		171			(218	)		24.66			—			—
	Restricted stock units granted(1)		(2,627	)		—			—			1,642			18.36
	Restricted stock units vested(1)		—			—			—			(1,110	)		22.02
	Restricted stock units expired or forfeited(1)		410			—			—			(254	)		18.82
	Balance at April 30, 2014—shares available for grant		6,921			—			—			—			—
	Balance at April 30, 2014—options		—			4,003			19.04			—			—
	Balance at April 30, 2014—restricted stock units		—			—			—			2,732			18.57
	Exercisable at April 30, 2014		—			2,806			18.94			—			—
	Vested and expected to vest at April 30, 2014—options		—			3,894		$	19.06			—			—
	Vested and expected to vest at April 30, 2014—restricted stock units		—			—			—			2,430		$	18.57
	-1
	Shares subject to awards granted for less than fair market value on the date of grant count against the share reserve as two shares for every one share subject to such an award. When a share is returned to the plan, two shares will be credited back to the reserve. With the approval of the Company's stockholders in September 2009, the Company modified certain terms of the 2007 Plan. Specifically, for restricted stock units granted after September 2009, the grant will count against the share reserve as 1.6 shares for every one share granted. When a share is returned to the plan which was granted after September 2009, 1.6 shares will be credited back to the reserve.
	As of April 30, 2014 and 2013, options to purchase 2,806,000 and 2,857,000 shares, respectively, were vested. Information regarding the options outstanding as of April 30, 2014 is summarized below:
		Options Outstanding												Options Exercisable
	Range of Exercise Prices	Options			Weighted			Weighted			Aggregate			Options			Weighted			Weighted		Aggregate
Outstanding		Average			Average			Intrinsic			Vested and			Average			Average			Intrinsic
		Remaining			Exercise			Value			Exercisable			Remaining			Exercise			Value
		Contractual			Price									Contractual			Price
		Life												Life
	(in thousands)			(in years)						(in thousands)			(in thousands)			(in years)					(in thousands)
$  5.82 - $13.34		875			5.01		$	12.34						570					$	11.8
$13.61 - $16.69		938			2.91			15.51						889						15.53
$16.85 - $18.47		964			4.9			18.04						305						17.11
$18.77 - $25.56		718			2.57			21.98						693						21.98
$34.80 - $34.80		508			4.17			34.8						349						34.8
$  5.82 - $34.84		4,003			3.95		$	19.04		$	11,589			2,806			3.26		$	18.94	$	8,792
The aggregate intrinsic value in the table above represents the total pretax intrinsic value (the aggregate difference between the closing stock price of the Company's common stock on April 30, 2014 of $19.53 and the exercise price of in-the-money options) that would have been received by the option holders had all option holders exercised their options as of that date. The total number of shares of common stock underlying in-the-money options exercisable as of April 30, 2014 was 1,933,798 shares.
The total intrinsic value of options exercised, the total intrinsic value of restricted stock units vested and the total cash received from employees as a result of employee stock option exercises during the periods indicated were as follows (in thousands):
	April 30,
	2014			2013
Total intrinsic value of options exercised	$	1,784		$	1,015
Total intrinsic value of restricted stock units vested		20,330			12,096
Total cash received from employees as a result of employee stock option exercises	$	6,825		$	1,085
Unrecognized compensation expense and the weighted average period over which the Company expects to recognize such compensation as of the dates indicated were as follows (dollars in thousands):
	April 30,
	2014			2013
Unvested stock options:
Unrecognized compensation expense, net of forfeitures	$	8,403		$	8,444
Weighted average period (years)		2.5			2.5
Unvested restricted stock units:
Unrecognized compensation expense, net of forfeitures	$	28,749		$	28,818
Weighted average period (years)		1.7			1.7
2009 Purchase Plan:
Unrecognized compensation expense	$	3,396		$	1,063
Weighted average period (years)		1.1			0.6
The Company's current policy is to issue new shares to settle the exercise of stock options and prospectively, the vesting of restricted stock units.
Valuation Assumptions
The authoritative guidance for stock-based compensation requires companies to estimate the fair value of stock-based compensation awards on the measurement date. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service period in the Company's Consolidated Statements of Income.
For restricted stock unit awards, the per-share fair value is the closing market price of the Company's common stock as reported on the NASDAQ Global Market ("NASDAQ") on the measurement date. For stock option awards and rights issued under the Company's employee stock purchase plans, the Company measures the fair value using the Black-Scholes option pricing model. Black-Scholes was developed to estimate the fair value of freely tradable, fully transferable options without vesting restrictions. These assumptions differ significantly from the characteristics of the Company's stock-based compensation awards. Black-Scholes also requires the use of highly subjective, complex assumptions, including expected term and the price volatility of the Company's stock.
The fair value for these options was estimated using the Black-Scholes option pricing model. The per share weighted average estimated grant date fair value for employee options granted during the periods indicated was as follows:
	Year Ended April 30,
	2014			2013			2012
Per share weighted average estimated grant date fair value	$	7.92		$	6.36		$	15.37
The following weighted average assumptions are included in the estimated fair value calculations for stock options granted in the periods indicated:
	Employee Stock									Employee Stock
	Option Plans									Purchase Plan
	Year Ended									Year Ended
	April 30,									April 30,
	2014			2013			2012			2014			2013			2012
Risk-free interest rate		1	%		0.6	%		1.3	%		0.1	%		0.1	%		0.1	%
Expected term of options (in years)		4.59			4.3			4.2			0.5			0.5			0.5
Expected volatility		51	%		60	%		55	%		46	%		63	%		53	%
Expected dividend yield		0	%		0	%		0	%		0	%		0	%		0	%
Using Black-Scholes, the per share weighted average estimated fair value of rights issued pursuant to the Company's employee stock purchase plans during the periods indicated was as follows:
	Year Ended April 30,
	2014			2013			2012
Per share weighted average estimated fair value of rights issued	$	5.83		$	6.06		$	5.54
The methodologies for determining the above values were as follows:
•
Expected term:  The expected term represents the period that the Company's stock-based awards are expected to be outstanding and is estimated based on historical experience.
•
Risk-free interest rate:  The risk-free interest rate assumption is based upon observed interest rates appropriate for the expected term of the Company's stock-based awards.
•
Expected volatility:  The Company determines expected volatility based on an average between the historical volatility of the Company's common stock and the implied volatility based on the Company's traded options with lives of six months or more. Averaging two data sources may provide a better proxy to what market place participants would use to value the Company's options.
•
Dividend yield:  The dividend yield assumption reflects the Company's intention not to pay a cash dividend under its dividend policy.
•
Estimated pre-vesting forfeitures:  When estimating pre-vesting forfeitures, the Company considers forfeiture behavior based on actual historical information.

Risks_and_Uncertainties

Risks and Uncertainties	12 Months Ended
	Apr. 30, 2014
Risks and Uncertainties	'
Risks and Uncertainties	'
	Note 14—Risks and Uncertainties
	Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, short-term investments, trade receivables and the interest rate swaps.
	The Company maintains cash and cash equivalents and short-term investments with various financial institutions, located in several different jurisdictions. The majority of the cash and cash equivalents balances are held in U.S. Cayman Islands and Singapore. The short-term investments are primarily held in U.S. and Cayman Islands. Deposits held with banks may generally be redeemed upon demand and may exceed the limit of insurance provided on such deposits. All these deposits and other financial instruments, including our interest rate swap, are maintained with financial institutions of reputable credit and therefore bear minimal credit risk. The Company has not sustained credit losses from instruments held at financial institutions.
	The Company's products are primarily sold to OEMs, VARs and to distributors. The Company's sales to significant customers as a percentage of revenues for the periods indicated were as follows:
		Year Ended April 30,
		2014			2013			2012
	Percentage of revenues:
	Customer A		13.8	%		10.7	%		*	%
	Customer B		12.5			10.3			*
	Customer C		11			11.7			13.5
	Customer D		*	%		18	%		15.2	%
	*
	Less than ten percent of revenues.
	The Company performs ongoing credit evaluations of its customers and maintains an allowance for doubtful accounts. Significant customer account receivables as a percentage of net accounts receivable for the periods indicated were as follows:
		April 30,
		2014			2013
	Percentage of accounts receivable, net:
	Customer A		17	%		*	%
	Customer B		12.7			15.1
	Customer C		10.4			*
	Customer D		*			15.3
	Customer E		*	%		11.1	%
	*
	Less than ten percent of accounts receivable, net.
	Certain of the Company's wafer, color filter application and packaging services are obtained from a single source or a limited group of suppliers. The partial or complete loss of one or more of these sources could have at least a temporary adverse effect on the Company's consolidated results of operations.

Segment_and_Geographic_Informa

Segment and Geographic Information	12 Months Ended
	Apr. 30, 2014
Segment and Geographic Information	'
Segment and Geographic Information	'
	Note 15—Segment and Geographic Information
	For all periods presented, the Company operated as a single reportable business segment.
	The Company sells its image-sensor products either directly to OEMs and VARs or indirectly through distributors. The following table illustrates the percentage of revenues from sales to OEMs and VARs and to distributors for the periods indicated, respectively:
		Year Ended April 30,
		2014			2013			2012
	OEMs and VARs		81.2	%		81.2	%		78.1	%
	Distributors		18.8			18.8			21.9
	Total		100	%		100	%		100	%
	Since the Company's customers' end-user customers market and sell their products worldwide, its revenues by geographic location are not necessarily indicative of the geographic distribution of end-user sales, but rather indicate where their components are sourced. The revenues by geography in the following table are based on the country or region in which the Company's customers issue their purchase orders for the periods presented (in thousands):
		Year Ended April 30,
		2014			2013			2012
	China	$	1,122,802		$	955,378		$	520,452
	South Korea		158,693			275,105			147,390
	Japan		89,311			57,604			46,108
	Taiwan		23,748			27,120			18,253
	United States		4,781			3,997			61,766
	All other		54,594			88,725			103,761
	Total	$	1,453,929		$	1,407,929		$	897,730
	The Company's long-lived assets, including its property, plant and equipment, net, long-term investments, land-use rights and other long-term assets are located in the following countries as of the dates indicated (in thousands):
		April 30,
		2014			2013
	China	$	162,207		$	139,482
	Taiwan		126,820			137,359
	United States		50,552			50,903
	All other		623			811
	Total	$	340,202		$	328,555

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Apr. 30, 2014
Commitments and Contingencies	'
Commitments and Contingencies	'
	Note 16—Commitments and Contingencies
	Commitments
	During the three months ended July 31, 2013, the Company formed OmniVision Technologies (Wuhan) Co. Ltd. ("OV-Wuhan"), a wholly-owned subsidiary in Wuhan, China, to support the Company's growing research and development efforts. OV-Wuhan had an initial registered capital requirement of $1.0 million, and we increased to $3.5 million in January 2014. As of April 30, 2014, the Company has contributed $3.5 million to OV-Wuhan, meeting the registered capital commitment requirement.
	The Company leases certain facilities and software under non-cancelable operating lease agreements. The non-cancelable operating leases expire at various dates through fiscal 2019. At April 30, 2014, future minimum lease commitments under operating leases are as follows (in thousands):
	Years Ended April 30,
	2015	$	6,012
	2016		5,378
	2017		2,078
	2018		816
	2019		796
	Thereafter		1,320
	Total	$	16,400
	The following table presents rental expenses under all operating leases during the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Rental expenses under operating leases	$	9,775	$	11,491	$	9,293
	Litigation
	From time to time, the Company has been subject to legal proceedings and claims with respect to such matters as patents, product liabilities and other actions arising out of the normal course of business.
	Ziptronix, Inc. v. OmniVision Technologies, Inc., Taiwan Semiconductor Manufacturing Company Ltd., and TSMC North America Corp.
	On December 6, 2010, Ziptronix, Inc. ("Ziptronix") filed a complaint alleging patent infringement against the Company in the District Court for the Northern District of California. The case is entitled Ziptronix, Inc. v. OmniVision Technologies, Inc., Taiwan Semiconductor Manufacturing Company Ltd., and TSMC North America Corp., Case No. CV10-05525. In its complaint, Ziptronix asserts that the Company has made, used, offered to sell, sold and/or imported into the United States image sensors that infringe the following six patents: U.S. Patent Nos. 7,387,944 ("Method for Low Temperature Bonding and Bonded Structure"), 7,335,572 ("Method for Low Temperature Bonding and Bonded Structure"), 7,553,744 ("Method for Low Temperature Bonding and Bonded Structure"), 7,037,755 ("Three Dimensional Device Integration Method and Integrated Device"), 6,864,585 ("Three Dimensional Device Integration Method and Integrated Device"), and 7,807,549 ("Method for Low Temperature Bonding and Bonded Structure"). The complaint seeks unspecified monetary damages, enhanced damages, interest, fees, expenses, costs, and injunctive relief against the Company. The Company answered the complaint on May 4, 2011 and denied each of Ziptronix's infringement claims against it.
	On November 22, 2011, Defendants Taiwan Semiconductor Manufacturing Company Ltd., and TSMC North America Corp. (collectively "TSMC") filed amended counterclaims asserting that Ziptronix has infringed, actively induced infringement of, and/or induced contributory infringement of the following five patents: U.S. Patent Nos. 6,682,981 ("Stress Controlled Dielectric Integrated Circuit Fabrication"), 7,307,020 ("Membrane 3D IC Fabrication"), 6,765,279 ("Membrane 3D IC Fabrication"), 7,385,835 ("Membrane 3D IC Fabrication"), and 6,350,694 ("Reducing CMP Scratch, Dishing and Erosion by Post CMP Etch Back Method for Low-K Materials"). Ziptronix answered the amended counterclaims on December 9, 2011 and denied each of TSMC's infringement claims against it.
	On August 9, 2012, Ziptronix filed a second amended complaint adding claims that the defendants infringe the following three patents: U.S. Patent Nos. 8,153,505 ("Method for Low Temperature Bonding and Bonded Structure"), 8,043,329 ("Method for Low Temperature Bonding and Bonded Structure"), and 7,871,898 ("Method for Low Temperature Bonding and Bonded Structure"). The Company answered the second amended complaint on August 27, 2012, and denied each of Ziptronix's infringement claims against it.
	Claim construction briefing has been submitted, and the parties await scheduling of a claim construction hearing. On January 22,2014, TSMC filed a motion for summary judgment of noninfringment. TSMC's motion for summary judgment is fully briefed. The Company expects to vigorously defend itself against Ziptronix's allegations. The Company is currently unable to predict the outcome of this complaint and therefore cannot determine the likelihood of loss nor estimate the loss or a range of possible loss.
	Securities Litigation
	On October 26, 2011, the first of several putative class action complaints was filed in the United States District Court for the Northern District of California against the Company and three of its executives, one of whom is a director. All of the complaints alleged that the defendants violated the federal securities laws by making misleading statements or omissions regarding the Company's business and financial results, in particular regarding the use of its imaging sensors in Apple Inc.'s iPhone. These actions have been consolidated as In re OmniVision Technologies, Inc. Litigation, Case No. 11-CV-5235 (RMW) (the "Securities Case"). On April 23, 2012, plaintiffs filed a consolidated complaint on behalf of a purported class of purchasers of the Company's common stock between August 27, 2010 and November 6, 2011, seeking unspecified damages. On March 29, 2013, the court denied the defendants' motion to dismiss. No trial date has been set. The Company is currently unable to predict the outcome of this action and therefore cannot determine the likelihood of loss nor estimate the loss or a range of possible loss.
	Derivative Litigation
	On November 15, 2011, the first of three shareholder derivative complaints was filed in the Superior Court of California, County of Santa Clara, against several of the Company's current and former officers and directors. These three state court actions were consolidated under the caption In re OmniVision Technologies, Inc. Derivative Litigation, Case No. 1-12-CV-216875. On March 21, 2012, a fourth similar shareholder derivative complaint captioned Carpenters Pension Fund of West Virginia v. Shaw Hong, et al., Case No. 12-CV-1423, was filed in the United States District Court for the Northern District of California. On May 10, 2012, a fifth similar shareholder derivative complaint captioned Edker Pope v. Shaw Hong, et. al., Case No. 7514, was filed in the Court of Chancery of the State of Delaware. These complaints make allegations similar to those presented in Securities Case, but they assert various state law causes of action, including claims of breach of fiduciary duty and unjust enrichment. All of these derivative complaints seek unspecified damages on behalf of the Company, which is named solely as nominal defendant against whom no recovery is sought. The proceedings in these derivative actions have been stayed by agreement pending the outcome of a future summary judgment motion in the Securities Case. The Company is currently unable to predict the outcome of these actions and therefore cannot determine the likelihood of loss nor estimate the loss or a range of possible loss.
	Requests for Indemnification
	In March 2011, a third party filed a complaint in a federal district court asserting patent infringement claims against some of the end-user customers of OmniVision's products. Among other things, the complaint asserts that the defendants' products incorporating the Company's image sensors infringe certain patents held by the third party plaintiff. The complaint sought unspecified monetary damages, fees and expenses and injunctive relief against the defendants. In April 2013, the parties to this action agreed to resolve all claims pursuant to settlement agreements, and the case was closed in July 2013. The Company was not a party to this lawsuit, but certain parties have requested indemnification from the Company for this matter to the extent that the infringement claims related to the Company's image sensors. The Company is currently unable to predict the outcome of any indemnity-related negotiations or other matters and therefore cannot determine the likelihood of loss nor estimate the loss or a range of possible loss.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Apr. 30, 2014
Related Party Transactions	'
Related Party Transactions	'
	Note 17—Related Party Transactions
	The following table presents the amounts paid for services provided by related parties and the balances payable for the periods indicated (in thousands):
				Year Ended April 30,
	Related Party	Description		2014			2013			2012
	VisEra	Purchases of color filter and other manufacturing services		$	119,919		$	166,100		$	121,008
		Rent and other services(1)		$	3		$	3,664		$	1,972
		Balance payable at year end, net		$	19,160		$	28,024		$	17,329
	WLCSP	Purchases of packaging services		$	2,097		$	—		$	—
		Balance payable at year end, net		$	1,156		$	—		$	—
	-1
	The Company leased manufacturing floor space from VisEra from November 2011 to May 2013.
	Supplementary Data (Unaudited)
		Three Months Ended
		July 31,			October 31,			January 31,			April 30,
		2013			2013			2014			2014
		(in thousands, except per share data)
	Revenues	$	373,688		$	397,249		$	352,023		$	330,969
	Cost of revenues		308,527			322,383			282,891			264,406
	Gross profit		65,161			74,866			69,132			66,563
	Net income	$	23,061		$	26,303		$	30,560		$	15,073
	Net income per share:
	Basic(1)	$	0.42		$	0.47		$	0.55		$	0.27
	Diluted(1)	$	0.42		$	0.47		$	0.54		$	0.26
	Shares used in computing net income per share:
	Basic		54,611			55,584			55,913			56,042
	Diluted		55,344			55,732			56,186			56,882
		Three Months Ended
		July 31,			October 31,			January 31,			April 30,
		2012			2012			2013			2013
		(in thousands, except per share data)
	Revenues	$	258,064		$	390,137		$	423,513		$	336,215
	Cost of revenues		208,849			325,453			352,027			277,486
	Gross profit		49,215			64,684			71,486			58,729
	Net income	$	2,327		$	10,345		$	21,308		$	8,922
	Net income per share:
	Basic(1)	$	0.04		$	0.19		$	0.4		$	0.17
	Diluted(1)	$	0.04		$	0.19		$	0.4		$	0.17
	Shares used in computing net income per share:
	Basic		52,830			53,514			53,830			53,943
	Diluted		52,865			53,675			53,930			54,061
	-1
	Net income per share is computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted per share information may not equal annual basic and diluted earnings per share.

Supplementary_Data_Unaudited

Supplementary Data (Unaudited)	12 Months Ended
	Apr. 30, 2014
Supplementary Data (Unaudited)	'
Supplementary Data (Unaudited)	'
	Supplementary Data (Unaudited)
		Three Months Ended
		July 31,		October 31,		January 31,		April 30,
		2013		2013		2014		2014
		(in thousands, except per share data)
	Revenues	$	373,688	$	397,249	$	352,023	$	330,969
	Cost of revenues		308,527		322,383		282,891		264,406
	Gross profit		65,161		74,866		69,132		66,563
	Net income	$	23,061	$	26,303	$	30,560	$	15,073
	Net income per share:
	Basic(1)	$	0.42	$	0.47	$	0.55	$	0.27
	Diluted(1)	$	0.42	$	0.47	$	0.54	$	0.26
	Shares used in computing net income per share:
	Basic		54,611		55,584		55,913		56,042
	Diluted		55,344		55,732		56,186		56,882
		Three Months Ended
		July 31,		October 31,		January 31,		April 30,
		2012		2012		2013		2013
		(in thousands, except per share data)
	Revenues	$	258,064	$	390,137	$	423,513	$	336,215
	Cost of revenues		208,849		325,453		352,027		277,486
	Gross profit		49,215		64,684		71,486		58,729
	Net income	$	2,327	$	10,345	$	21,308	$	8,922
	Net income per share:
	Basic(1)	$	0.04	$	0.19	$	0.4	$	0.17
	Diluted(1)	$	0.04	$	0.19	$	0.4	$	0.17
	Shares used in computing net income per share:
	Basic		52,830		53,514		53,830		53,943
	Diluted		52,865		53,675		53,930		54,061
	-1
	Net income per share is computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted per share information may not equal annual basic and diluted earnings per share.

SCHEDULE_II_VALUATION_AND_QUAL

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Apr. 30, 2014
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	'
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	'
	SCHEDULE II
	OMNIVISION TECHNOLOGIES, INC.
	VALUATION AND QUALIFYING ACCOUNTS
	For the Years Ended April 30, 2014, 2013 and 2012
	(In thousands)
	Description	Balance at		Additions			Write-offs		Balance at
		Beginning of		and Charges			and		End of Year
		Year		to Expenses			Deductions
	Allowance for doubtful accounts:
	Fiscal year ended April 30, 2014	$	945	$	53		$	—	$	998
	Fiscal year ended April 30, 2013	$	555	$	390		$	—	$	945
	Fiscal year ended April 30, 2012	$	1,834	$	(174	)	$	1,105	$	555
	Deferred tax valuation allowance:
	Fiscal year ended April 30, 2014	$	12,116	$	5,210		$	—	$	17,326
	Fiscal year ended April 30, 2013	$	10,419	$	1,697		$	—	$	12,116
	Fiscal year ended April 30, 2012	$	8,058	$	2,361		$	—	$	10,419
	Allowance for sales returns:
	Fiscal year ended April 30, 2014	$	5,371	$	—		$	2,265	$	3,106
	Fiscal year ended April 30, 2013	$	2,489	$	10,327		$	7,445	$	5,371
	Fiscal year ended April 30, 2012	$	2,305	$	3,283		$	3,099	$	2,489

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	12 Months Ended
	Apr. 30, 2014
Basis of Presentation	'
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and judgments on its historical experience, knowledge of current conditions and beliefs of what could occur in the future considering available information. Actual results could differ from these estimates.
Equity in Earnings of China WLCSP Limited	'
	Equity in Earnings of China WLCSP Limited
	The Company applies the equity method of accounting for its investment in China WLCSP Limited ("WLCSP"), and the Company's portion of net income recorded by WLCSP is presented in "Equity in earnings of investee." Through October 31, 2013, the Company was able to include in its fiscal quarter results its share of WLCSP's earnings or losses for the same fiscal periods. In January 2014, however, WLCSP completed its initial public offering and became a public company in China. (See Note 5.) Under China's securities laws, the Company is not able to disclose any periodic financial information about WLCSP which may otherwise be available to the Company in its capacity as a representative on WLCSP's Board of Directors, until such information is publicly released in China. Furthermore, WLCSP will only report its earnings on a calendar-quarter basis. Consequently, starting with the fourth quarter of fiscal 2014, the Company introduced a one-month lag in its equity method of accounting for WLCSP. For fiscal 2014, under "Equity in earnings of investee," the Company only included its share of WLCSP's earnings from May 1, 2013 to March 31, 2014. For fiscal quarters beginning after May 1, 2014, the Company will include in its results of operations its share of WLCSP's earnings or losses from the calendar quarter that is one month in arrears. The introduction of a one-month lag in the equity method of accounting for WLCSP has no material effects on any prior years' or the current year's consolidated balance sheets, statements of income or cash flows. Accordingly, prior years' financial statements have not been recast to reflect the new policy.
Classification of land use Rights	'
	Classification of land use Rights
	Certain previously reported amounts have been revised to correct the classification of land-use rights from "Property, plant and equipment, net" to "Other long-term assets" as of April 30, 2013. The net book value of the Company's land-use rights totaled approximately $2.2 million at April 30, 2014 and April 30, 2013, respectively. The reclassification had no impact on the results of operations or cash flows of the Company.
	The net book value of the Company's land-use rights comprises three separate arrangements. One of the Company's wholly-owned subsidiaries, OmniVision Semiconductor (Shanghai) Co. Ltd. ("OSC"), formerly Hua Wei Semiconductor (Shanghai) Co. Ltd., holds a land-use right that was acquired from the Shanghai SongJiang Housing and Land Administration Bureau in December 2000 for approximately $0.8 million. The cost of the land-use right is being amortized over 40 years, the useful life of the right.
	In January 2007, the Company, through its wholly-owned subsidiary, OmniVision Technologies (Shanghai) Co. Ltd. ("OTC"), formerly Shanghai OmniVision IC Design Co. Ltd., entered into a land-use-right agreement with the Construction and Transportation Commission of the Pudong New District, Shanghai. The agreement has an effective date of December 31, 2006. Under the terms of the agreement, the Company paid an aggregate amount of approximately $0.6 million in exchange for the right to use approximately 323,000 square feet of land located in Shanghai, China. The cost of the land-use right is being amortized over 50 years, the useful life of the right.
	In addition, in July 2011, the Company, through its wholly-owned subsidiary, Shanghai OmniVision Semiconductor Technology Co. Ltd. ("OST"), entered into a land-use-right agreement with the Shanghai SongJiang District Zoning and Land Administration Bureau. Under the terms of the agreement, the Company paid an aggregate amount of approximately $1.0 million in exchange for the right to use approximately 113,175 square feet of land located in Shanghai for a period of 50 years, starting from August 19, 2011. The cost of the land-use right is being amortized over 50 years, the useful life of the right.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Apr. 30, 2014
Summary of Significant Accounting Policies	'
Principles of Consolidation	'
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant inter-company accounts and transactions have been eliminated.
Foreign Currency Translation	'
	Foreign Currency Translation
	All of the Company's wholly-owned subsidiaries use the U.S. dollar as their respective functional currency. For these subsidiaries with assets or liabilities denominated in currencies other than the U.S. dollar, non-monetary assets are remeasured into U.S. dollars using historical rates of exchange. Monetary assets and liabilities are remeasured into U.S. dollars using exchange rates prevailing on the balance sheet date. The remeasurement gains or losses are included in "Other income (expense), net." For fiscal 2014 and 2013, the Company recorded remeasurement losses of $1.5 million and $405,000 in "Other income (expense), net," respectively. For fiscal 2012, the Company recorded a remeasurement gain of $117,000 in "Other income (expense), net."
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with a maturity at the date of purchase of three months or less to be cash equivalents. Cash equivalents consist principally of money market funds. (See Note 4.)
	The Company maintains the majority of its cash and cash equivalent balances with major financial institutions in the United States, Cayman Islands and Singapore. These balances are subject to a concentration of credit risk and only a small proportion of these balances are covered by Federal Deposit Insurance Corporation ("FDIC") insurance. The Company places its cash investments in instruments that meet high credit quality standards, as specified in the Company's investment policy guidelines.
Short-Term Investments	'
	Short-Term Investments
	The Company's short-term investments, which are classified as available-for-sale securities, are invested in high-grade corporate securities, municipal bonds and notes and U.S. government debt and agencies securities with a final maturity of eighteen months or less from the date of purchase.
	Short-term investments are reported at fair value at April 30, 2014 and 2013. Unrealized gains or losses are recorded in stockholders' equity and included in "Accumulated other comprehensive income." Short-term investments with declines in value which are judged to be other than temporary, of which there were none in the periods presented, would be written down to their fair values, at the time such judgment is made.
Accounts Receivable	'
	Accounts Receivable
	Accounts receivable are recorded at invoiced amounts and do not bear interest. The Company performs ongoing credit evaluations of its customers' financial condition and, generally, requires no collateral from its customers. Allowances for doubtful accounts and sales returns are established based on various factors including credit profiles of the Company's customers, contractual terms and conditions, historical payments, returns and discounts experience, and current economic trends. The Company reviews its allowance for doubtful accounts quarterly by assessing individual accounts receivable over a specific aging and amount, and all other balances on a pooled basis based on historical collection experience and economic risk assessment. Accounts receivable are written off on a case-by-case basis, net of any amounts that may be collected. The Company determines its allowance for sales returns through evaluation of historical sales returns and other known factors and provides for estimated sales returns in the same period it records the related revenues. To estimate the allowance for sales returns, the Company analyzes potential customer specific product application issues, potential quality and reliability issues and historical returns. The Company evaluates the adequacy of the allowance for sales returns on a quarterly basis. This allowance is reflected as a reduction to accounts receivable in the Company's consolidated balance sheets. Increases to the allowance are recorded as a reduction to revenues.
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	Due to their short maturities, the reported amounts of the Company's financial instruments, including cash equivalents, short-term investments, accounts receivable, accounts payable and other current liabilities approximate fair value.
	The fair values of the Company's mortgage loan and construction loan approximate book value as the underlying interest rates are based on risk-adjusted market rates. (See Note 7.)
	Related to the mortgage debt, the Company has one outstanding interest rate swap arrangement as of April 30, 2014. The Company recognizes this derivative instrument at the reporting date as either an asset or liability in its Consolidated Balance Sheets, measured at fair value. The accounting for changes in fair value of a derivative depends on the intended use of the derivative and the associated hedging designation. The Company has designated the swap as an economic hedge and records the changes in fair value in "Other income (expense), net." (See Note 7.)
Property, Plant and Equipment	'
	Property, Plant and Equipment
	Property, plant and equipment is stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets as follows:
	Buildings	40 years
	Building/leasehold improvements	Shorter of 20 years or life of lease
	Machinery and equipment	2 - 10 years
	Furniture and fixtures	3 - 7 years
	Construction in progress includes project costs paid to third parties that are clearly associated with the acquisition, development, and construction of an asset and are capitalized as a cost of that project prior to the use of the asset. Such costs include the costs of materials, interest, legal, and escrow services. These capitalized project costs are not subject to depreciation until the assets to which they are related are placed into production.
Long-Lived Assets	'
	Long-Lived Assets
	The Company reviews its long-lived assets, including intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. When such an event occurs, the Company estimates the undiscounted future cash flows expected to result from the use of the asset and its eventual disposition. If the undiscounted expected future cash flows are less than the carrying amount of the asset, an impairment loss is recognized in order to write-down the carrying value of the asset to its estimated fair market value. To date, the Company has not recognized any impairment losses.
Inventories	'
	Inventories
	Inventories are stated at the lower of cost, determined on a first-in, first-out ("FIFO") basis, or market.
	The Company records a provision to reduce the carrying value of inventories to their net realizable value when the Company believes that the net realizable value is less than cost. The Company also records a provision for the cost of inventories when the number of units on hand exceeds the number of units that the Company forecasts will be sold over a certain period of time, generally 12 months. Where necessary, these provisions take into account the inventories owned and not yet sold by certain of the Company's distributors. The recording of these provisions establishes a new and lower cost basis for each specifically identified inventory item, and the Company does not restore the cost basis to its original level regardless of any subsequent changes in facts or circumstances. Recoveries are only recognized upon the sale of previously written-down inventories.
Goodwill	'
	Goodwill
	The Company records goodwill when the consideration paid for an acquisition exceeds the fair value of net tangible and intangible assets acquired, including related tax effects. Goodwill is not amortized; instead goodwill is tested for impairment on an annual basis, or more frequently if the Company believes indicators of impairment exist. The Company first assesses qualitative factors to determine whether it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value. If the Company determines that the fair value is less than the carrying value, the Company will use a two-step process to determine the amount of goodwill impairment. The first step requires comparing the fair value of the reporting unit to its net book value, including goodwill. A potential impairment exists if the fair value of the reporting unit is lower than its net book value. The second step of the process, which is performed only if a potential impairment exists, involves determining the difference between the fair value of the reporting unit's net assets other than goodwill and the fair value of the reporting unit. If this difference is less than the net book value of goodwill, an impairment exists and is recorded.
Warranty for Defective Products	'
	Warranty for Defective Products
	The Company warrants to its customers that its products will work in accordance with each product's specifications. Due to the cost and other complexities associated with rectifying any product defects, the Company does not repair any defective products. If a product is defective, the customer notifies the Company and, with the Company's approval, returns the defective product. The Company then sends replacement products to the customer. Accordingly, the Company accounts for any exposure related to defective products as a portion of its allowance for sales returns.
Treasury Stock	'
	Treasury Stock
	The Company accounts for treasury stock under the cost method and includes treasury stock as a component of stockholders' equity.
Revenue Recognition	'
	Revenue Recognition
	For shipments to customers without agreements that allow for returns or credits, principally original equipment manufacturers ("OEMs") and value added resellers ("VARs"), the Company recognizes revenue using the "sell-in" method. Under this method, the Company recognizes revenue upon the shipment of products to the customer provided that the Company has received a signed purchase order, the price is fixed or determinable, title and risk of loss has transferred to the customer, collection of resulting receivables is considered reasonably assured, product returns are reasonably estimable, there are no customer acceptance requirements and there are no remaining material obligations. At the time revenue is recognized, the Company provides for future returns of potentially defective product based on historical experience. For cash consideration given to customers, that is primarily in the form of rebates and for which the Company does not receive a separately identifiable benefit or cannot reasonably estimate fair value, the Company records the amounts as reductions of revenue.
	For shipment of products sold to distributors under agreements allowing for returns or credits, title and the risk of ownership to the products transfer to the distributor upon shipment, and the distributor is obligated to pay for the products whether or not the distributor has sold them at the time payment is due. Under the terms of the Company's agreements with such distributors and subject to the Company's prior approval, distributors are entitled to reclaim from the Company as price adjustments the difference, if any, between the prices at which the Company sold the product to the distributors and the prices at which the product is subsequently sold by the distributor. In addition, distributors have limited rights to return inventory that they determine is in excess of their requirements, and accordingly, in determining the appropriate level of provision for excess and obsolete inventory, the Company takes into account the inventories held by its distributors. For these reasons, the price is not considered fixed or determinable until the distributor resells the products to the Company's end-user customers and the distributor notifies the Company in writing of the details of such sales transactions. Accordingly, the Company recognizes revenue using the "sell-through" method. Under the "sell-through" method, the Company defers the revenue, adjustments to revenue and the related costs of revenue until the final resale of such products to end customers. The amounts billed to these distributors and adjustments to revenue and the cost of inventory shipped to, but not yet sold by, the distributors are shown net on the Consolidated Balance Sheets as "Deferred revenues, less cost of revenues."
Research, Development and Related	'
	Research, Development and Related
	The Company recognizes the costs associated with the internal development of intellectual property rights as expense when incurred. Also included in "Research, Development and Related" are expenses associated with patent, copyright, trademark and trade secrets. The Company recorded the following research and development expenses for the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Research and development expenses	$	114,224	$	109,026	$	106,587
Amortization of Acquired Patent Portfolio	'
	Amortization of Acquired Patent Portfolio
	The Company recognizes amortization expense associated with the patent portfolio acquired from Eastman Kodak Company ("Kodak") in March 2011 as "Amortization of acquired patent portfolio."
Advertising	'
	Advertising
	All of the Company's advertising costs are expensed as incurred.
Income Taxes	'
	Income Taxes
	The Company accounts for deferred income taxes using the liability method, under which it recognizes as deferred tax assets and liabilities the expected future tax consequences of timing differences between the book and tax basis of assets and liabilities. The Company establishes valuation allowances to reduce deferred tax assets as necessary when management estimates, based on available objective evidence, that it is more-likely-than-not that the Company will not realize the benefit of its deferred tax assets.
	The Company recognizes in its consolidated financial statements the impact of a tax position that, based on the technical merits of the position, is more-likely-than-not to be sustained upon examination. The evaluation of a tax position in accordance with this interpretation is a two-step process. In the first step, recognition, the Company determines whether it is more-likely-than-not that a tax position will be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. The second step addresses measurement of a tax position that meets the more-likely-than-not criterion. The tax position is measured at the largest amount of benefit that has a greater than 50 percent likelihood of being realized upon ultimate settlement. Tax positions that previously failed to meet the more-likely-than-not recognition threshold will be recognized in the first subsequent financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more-likely-than-not recognition threshold will be de-recognized in the first subsequent financial reporting period in which that threshold is no longer met.
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company recognizes in its consolidated financial statements all share-based payments to employees, including grants of employee stock options and of other stock-based compensation under the 2007 Equity Incentive Plan and the 2000 Stock Plan, and employee stock purchases under the 2009 Employee Stock Purchase Plan and the 2000 Employee Stock Purchase Plan, based on their respective measurement date fair values. The 2007 Equity Incentive Plan replaced the 2000 Stock Plan, and the 2009 Employee Stock Purchase Plan replaced the 2000 Employee Stock Purchase Plan.
	Stock-based compensation is measured at the measurement date, based on the fair value of the award. For stock options, fair value is measured using the Black-Scholes option pricing model ("Black-Scholes"), and for restricted stock units, fair value is based on the market price of the Company's common stock. The expenses are recognized over the requisite service period of the award. The Company has chosen to recognize stock-based compensation expense using the straight-line attribution method. Black-Scholes requires the use of highly subjective, complex assumptions, including the expected term and the price volatility of the Company's stock. The Company is required to estimate forfeiture rates at the time of grant and revise such estimates, if necessary, in subsequent periods if actual forfeitures differ from initial estimates. Stock-based compensation expense was recorded net of estimated forfeitures such that expense was recorded only for those stock-based awards that are expected to vest.
	The Company elected to use the long-form method to establish the beginning balance of, and to determine the subsequent impact on, the additional paid-in capital pool. The Company has also elected to use the "with and without" approach in determining the order in which tax attributes are utilized. As a result, the Company will recognize a tax benefit from stock-based awards in additional paid-in capital only if an incremental tax benefit is realized after all other tax attributes currently available to the Company have been utilized. In addition, the Company has elected to account for the indirect effects of stock-based awards on other tax attributes, such as research and development tax credits, through the Consolidated Statements of Income.
Basic and Diluted Net Income Per Share	'
	Basic and Diluted Net Income Per Share
	The Company computes net income per share in accordance with authoritative guidance for earnings per share, under the provisions of which basic income per share is computed by dividing the income available to holders of common stock for the period by the weighted average number of shares of common stock outstanding during the period. The calculation of diluted net income per share excludes potential common stock if the effect of such stock is antidilutive. Potential common stock consists of incremental common shares issuable upon the exercise of stock options, purchases via employee stock purchase plans, and vesting of restricted stock units.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In March 2013, the Financial Accounting Standards Board ("FASB") revised the authoritative guidance on accounting for cumulative translation adjustment. The revised guidance specifies that a cumulative translation adjustment should be released into earnings when an entity ceases to have a controlling financial interest in a subsidiary or a group of assets within a consolidated foreign entity and the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For sales of an equity method investment that is a foreign entity, a pro rata portion of cumulative translation adjustment attributable to the investment would be recognized in earnings upon sale of the investment. The guidance is effective for the Company beginning in the first quarter of fiscal 2015. The Company does not expect the adoption of this guidance to have any material impact on its financial position, results of operations or cash flows.
	In July 2013, the FASB issued final guidance on the presentation of certain unrecognized tax benefits in the financial statements. Under the new guidance, a liability related to an unrecognized tax benefit would be offset against a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward if such settlement is required or expected in the event the uncertain tax position is disallowed. The guidance is effective for the Company beginning in the first quarter of fiscal 2015. The Company expects that its long-term income taxes payable to decrease and its deferred tax liabilities—non-current to increase in the first quarter of fiscal 2015 as a result of the adoption of this guidance.
	In April 2014, the FASB revised the authoritative guidance on reporting discontinued operations. The revised guidance specifies that a disposal of a component of an entity or a group of components of an entity is required to be reported in a discontinued operation if the disposal represents a strategic shift that has, or will have a major effect on an entity's operations and financial results. The guidance also changes the requirements for reporting discontinued operations which requires additional disclosures for discontinued operations and new disclosures for individually material disposal transactions that do not meet the definition of a discontinued operation. The guidance is effective for the Company beginning in the first quarter of fiscal 2016. The Company is currently evaluating the impact this guidance may have on its financial position, results of operations and cash flows.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Apr. 30, 2014
Summary of Significant Accounting Policies	'
Schedule of estimated useful lives of the assets	'
	Buildings	40 years
	Building/leasehold improvements	Shorter of 20 years or life of lease
	Machinery and equipment	2 - 10 years
	Furniture and fixtures	3 - 7 years
Schedule of research and development expenses	'
	The Company recorded the following research and development expenses for the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Research and development expenses	$	114,224	$	109,026	$	106,587

ShortTerm_Investments_Tables

Short-Term Investments (Tables)	12 Months Ended
	Apr. 30, 2014
Short-Term Investments	'
Schedule of available-for-sale securities	'
	Available-for-sale securities as of the dates presented were as follows (in thousands):
		As of April 30, 2014
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
	Municipal bonds	$	6,168	$	1	$	(2	)	$	6,167
	Corporate debt securities/commercial paper		146,866		6		(46	)		146,826
		$	153,034	$	7	$	(48	)	$	152,993
	Contractual maturity dates, less than one year								$	142,758
	Contractual maturity dates, one to two years									10,235
									$	152,993
		As of April 30, 2013
		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value
				Gains		Losses
	Municipal bonds	$	1,707	$	—	$	—		$	1,707
	Corporate debt securities/commercial paper		20,463		—		(6	)		20,457
		$	22,170	$	—	$	(6	)	$	22,164
	Contractual maturity dates, less than one year								$	20,764
	Contractual maturity dates, two to twenty-three years									1,400
									$	22,164

Supplemental_Balance_Sheet_Acc1

Supplemental Balance Sheet Account Information (in thousands) (Tables)	12 Months Ended
	Apr. 30, 2014
Supplemental Balance Sheet Account Information (in thousands)	'
Schedule of supplemental balance sheet account information	'
	Supplemental Balance Sheet Account Information (in thousands)
		April 30,
		2014			2013
	Cash and cash equivalents:
	Cash	$	195,141		$	145,762
	Money market funds and U.S. government bonds		102,811			44,409
		$	297,952		$	190,171
	Accounts receivable, net:
	Accounts receivable	$	176,576		$	172,833
	Less: Allowance for doubtful accounts		(998	)		(945	)
	Allowance for sales returns		(3,106	)		(5,371	)
		$	172,472		$	166,517
	Inventories:
	Work in progress	$	107,621		$	213,095
	Finished goods		163,314			217,220
		$	270,935		$	430,315
	Prepaid expenses and other current assets:
	Prepaid expenses	$	4,285		$	7,974
	Deposits and other		1,284			3,907
	Interest receivable		1,007			101
		$	6,576		$	11,982
	Property, plant and equipment, net:
	Land	$	13,000		$	13,000
	Buildings		82,547			57,246
	Buildings/leasehold improvements		29,123			24,659
	Machinery and equipment		119,762			102,429
	Furniture and fixtures		5,002			5,013
	Software		8,774			6,954
	Construction in progress		2,894			37,725
			261,102			247,026
	Less: Accumulated depreciation and amortization		(107,310	)		(88,632	)
		$	153,792		$	158,394
	Other long-term assets:
	Deferred tax assets—non-current	$	528		$	6,251
	Land-use rights		2,180			2,236
	Other long-term assets		29,821			28,179
		$	32,529		$	36,666
	Accrued expenses and other current liabilities:
	Due to VisEra for acquisition of production operations	$	—		$	9,000
	Deferred tax liabilities—current		144			—
	Employee compensation		15,176			12,856
	Third party commissions		380			850
	Professional services		2,270			2,176
	Noncancelable purchase commitments		647			4,817
	Rebates		1,511			2,557
	Other		11,831			8,018
		$	31,959		$	40,274
	Other long-term liabilities:
	Interest rate swap	$	2,980		$	4,184
	Deferred tax liabilities—non-current		3,731			—
	Other		5,107			434
		$	11,818		$	4,618

LongTerm_Investments_Tables

Long-Term Investments (Tables)	12 Months Ended
	Apr. 30, 2014
Long-Term Investments	'
Schedule of long-term investments	'
	Long-term investments as of the dates indicated consisted of the following (in thousands):
		April 30,
		2014		2013
	VisEra	$	115,943	$	105,233
	WLCSP		33,805		22,539
	XinTec		4,661		4,661
	Tong Hsing		—		5,313
	Phostek		—		2,000
	Total	$	154,409	$	139,746
Schedule of dividend payments received from VisEra	'
	The Company received the following dividend payments from VisEra during the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Dividend payments received from VisEra	$	—	$	13,760	$	—
Schedule of equity income in VisEra	'
	The following table presents equity income before elimination of unrealized intercompany profits and the equity income recorded by the Company for the periods indicated in "Cost of revenues," consisting of its portion of the net income recorded by VisEra during the periods presented after the elimination of unrealized intercompany profits (in thousands).
		Year Ended April 30,
		2014		2013		2012
	Equity income	$	10,710	$	20,274	$	8,835
	Net effect on Cost of revenues, after the elimination of unrealized intercompany profits	$	17,228	$	15,752	$	7,326
Schedule of dividend payments received from WLCSP	'
	The Company received the following dividend payments from WLCSP during the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Dividend payments received from WLCSP	$	830	$	890	$	852
Schedule of equity income in WLCSP	'
	The following table presents equity income recorded by the Company for the periods indicated in "Equity in earnings of investee," consisting of its portion of the net income recorded by WLCSP during the periods presented, and equity method investment adjustments (in thousands).
		Year Ended April 30,
		2014		2013		2012
	Equity income	$	4,009	$	3,832	$	3,066
Schedule of investment in Tong Hsing Electronic Industries, Limited unrealized holding gains (losses)	'
	For the periods indicated, the Company recorded the following unrealized holding gains (losses) in "Accumulated other comprehensive income" (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Unrealized holding gains (losses)	$	566	$	859	$	(328	)
Schedule of summary financial information of VisEra Technologies Company, Ltd	'
	Each investee's financial information was prepared under GAAP (in thousands):
	VisEra Technologies Company, Ltd.
		Year Ended April 30,
		2014		2013		2012
	Operating data:
	Revenues	$	131,850	$	169,969	$	125,777
	Gross profit		50,426		58,531		32,607
	Income from operations		40,312		47,512		48,818
	Net income	$	32,121	$	31,921	$	32,482
		April 30,
		2014		2013
	Balance sheet data:
	Current assets	$	189,399	$	168,343
	Long-term assets		112,956		132,633
	Current liabilities		38,086		68,854
	Long-term liabilities	$	—	$	—
Schedule of summary financial information of WLCSP	'
	Each investee's financial information was prepared under GAAP (in thousands):
	China WLCSP Limited
				Year Ended
		11 Months		April 30,
		Ended
		March 31,
		2014		2013		2012
	Operating data:
	Revenues	$	75,480	$	57,340	$	47,700
	Gross profit		40,909		31,348		24,854
	Income from operations		26,428		23,742		18,458
	Net income	$	23,055	$	20,520	$	16,638
		March 31,		April 30,
		2014		2013
	Balance sheet data:
	Current assets	$	221,547	$	52,985
	Long-term assets		134,482		81,733
	Current liabilities		96,570		12,204
	Long-term liabilities	$	3	$	3
Schedule of Company's share of undistributed earnings of investees accounted for by equity method	'
	The Company's share of undistributed earnings of investees accounted for by the equity method as of the dates indicated were as follows (in thousands):
		April 30,
		2014		2013
	Undistributed earnings of investees	$	66,772	$	49,830

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Apr. 30, 2014
Goodwill and Intangible Assets	'
Schedule of change to carrying value of goodwill	'
	There was no change to the carrying value of the Company's goodwill during fiscal 2014 and 2013 as noted below (in thousands):
		Year Ended April 30,
		2014		2013
	Beginning balance, May 1	$	10,227	$	10,227
	Changes to carrying value		—		—
	Ending balance, April 30	$	10,227	$	10,227
Schedule of intangible assets	'
	Intangible assets as of the dates indicated consisted of the following (in thousands):
		April 30, 2014
		Cost		Accumulated		Net Book
				Amortization		Value
	Acquired patent portfolio	$	65,000	$	28,631	$	36,369
	Core technology		36,100		27,980		8,120
	Patents and licenses		36,066		14,438		21,628
	Trademarks and tradenames		1,400		1,400		—
	Customer relationships		340		240		100
	Intangible assets, net	$	138,906	$	72,689	$	66,217
		April 30, 2013
		Cost		Accumulated		Net Book
				Amortization		Value
	Acquired patent portfolio	$	65,000	$	19,345	$	45,655
	Core technology		36,100		25,649		10,451
	Patents and licenses		14,160		13,596		564
	Trademarks and tradenames		1,400		1,400		—
	Customer relationships		340		206		134
	Intangible assets, net	$	117,000	$	60,196	$	56,804
Schedule of amortization of intangibles	'
	The following table presents the amortization of intangibles recorded by the Company for the periods indicated (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Amortization of intangible assets	$	3,207	$	3,638	$	2,778
	Amortization of acquired patent portfolio	$	9,286	$	9,286	$	9,286
Schedule of expected future annual amortization of intangible assets	'
	The total expected future annual amortization of these intangible assets is as follows (in thousands):
	Years Ending April 30,
	2015	$	13,929
	2016		13,753
	2017		13,627
	2018		12,546
	2019		3,234
	Thereafter		9,128
	Total	$	66,217

Borrowing_Arrangements_and_Rel1

Borrowing Arrangements and Related Derivative Instruments (Tables)	12 Months Ended
	Apr. 30, 2014
Borrowing Arrangements and Related Derivative Instruments	'
Schedule of the Company's debt	'
	The following table sets forth the Company's debt as of the dates indicated (in thousands):
		April 30,
		2014			2013
	Mortgage loan	$	23,653		$	24,207
	Construction loan		12,179			15,271
			35,832			39,478
	Less: amount due within one year		(3,802	)		(3,769	)
	Non-current portion of long-term debt	$	32,030		$	35,709
Schedule of aggregate debt maturities	'
	As of April 30, 2014, aggregate debt maturities were as follows (in thousands):
	Years Ending April 30,	Mortgage			Construction			Total
		Loan			Loan
	2015	$	554		$	3,248		$	3,802
	2016		554			6,495			7,049
	2017		22,545			2,436			24,981
	Thereafter		—			—			—
	Total	$	23,653		$	12,179		$	35,832
Schedule of interest rates of mortgage loan	'
		April 30,
		2014			2013
	Mortgage Loan		1.1	%		1.1	%
Schedule of location of swaps on consolidated statements of income and consolidated balance sheets, and related effects on entity's results of operations and financial positions	'
	The table below presents the location of the swaps on the Consolidated Statements of Income and Consolidated Balance Sheets, and the related effects on the Company's results of operations and financial positions for the periods indicated (in thousands):
		Year Ended April 30,
		2014			2013			2012
	Location of amounts recognized in Consolidated Statements of Income and amount of gains (losses):
	Other income (expense), net	$	1,204		$	625		$	(880	)
		April 30,
		2014			2013
	Location of amounts on Consolidated Balance Sheets and fair values:
	Other long-term liabilities	$	2,980		$	4,184

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Apr. 30, 2014
Income Taxes	'
Schedule of provision for income taxes	'
	The provision for income taxes consists of the following (in thousands):
		Year Ended April 30,
		2014			2013			2012
	Current:
	Federal	$	5,802		$	7,746		$	3,068
	State		17			16			16
	Foreign		(4,315	)		3,863			808
	Total current		1,504			11,625			3,892
	Deferred:
	Federal		6,066			(2,261	)		3,356
	State		1,832			(837	)		(449	)
	Foreign		530			(1,265	)		—
	Total deferred		8,428			(4,363	)		2,907
	Total provision	$	9,932		$	7,262		$	6,799
Schedule of income (loss) before provision for income taxes	'
	Income (loss) before provision for income taxes consisted of (in thousands):
		Year Ended April 30,
		2014			2013			2012
	United States	$	(16,581	)	$	(20,996	)	$	2,280
	International		121,510			71,160			70,368
	Total	$	104,929		$	50,164		$	72,648
Schedule of differences in the provision for income taxes and the amount computed by applying the U.S. federal income tax rate	'
	The provision for income taxes differs from the amount computed by applying the U.S. federal income tax rate of 35.0% to "Income before income taxes" as a result of the following (in thousands):
		Year Ended April 30,
		2014			2013			2012
	Provision based on statutory federal income tax rate	$	36,725		$	17,557		$	25,426
	State income tax expense (benefit), net of federal tax benefit		1,849			(868	)		(481	)
	Foreign rate differential		(32,481	)		(14,843	)		(21,349	)
	Non-deductible stock-based compensation		6,678			7,412			5,583
	Tax credits		(3,691	)		(3,409	)		(2,979	)
	Prior year adjustment		—			1,184			—
	Other		852			229			599
	Tax provision	$	9,932		$	7,262		$	6,799
Schedule of components of net deferred tax assets	'
	The components of net deferred tax assets included in the consolidated balance sheets for the fiscal years indicated were (in thousands):
		April 30,
		2014			2013
	Deferred tax assets:
	Tax credits	$	28,589		$	23,832
	Net operating loss		3,099			1,612
	Stock-based compensation expenses		7,406			7,230
	Unrealized loss on interest rate swap		1,044			1,694
	Fixed assets		533			1,355
	Accruals, reserves and other		6,174			6,105
	Gross deferred tax assets		46,845			41,828
	Valuation allowance		(17,326	)		(12,116	)
	Deferred tax assets		29,519			29,712
	Deferred tax liabilities:
	Undistributed earnings of non-US equity investees not permanently reinvested		(25,771	)		(17,735	)
	Other		(2,122	)		(1,698	)
	Deferred tax liabilities		(27,893	)		(19,433	)
	Net deferred tax assets	$	1,626		$	10,279
Schedule of reconciliation of the beginning balance and the ending balance of gross unrecognized tax benefits, excluding interest and penalties	'
	A reconciliation of the beginning balance and the ending balance of gross unrecognized tax benefits, excluding interest and penalties, is as follows (in thousands):
		April 30,
		2014			2013			2012
	Balance at beginning of fiscal year	$	90,561		$	87,433		$	85,734
	Increases in balances related to tax positions taken during current year		4,345			6,288			4,536
	Decreases as a result of lapses of the applicable statute of limitations		(8,507	)		(3,123	)		(2,667	)
	Increases in balances related to tax positions taken during prior years		1,363			422			89
	Decreases in balances related to tax positions taken during prior years		(3,531	)		(459	)		(259	)
	Balance at end of fiscal year	$	84,231		$	90,561		$	87,433
Schedule of reconciliation of the gross unrecognized tax benefits, including interest and penalties	'
	A reconciliation of the gross unrecognized tax benefits, including interest and penalties, as presented on the Consolidated Balance Sheets is as follows (in thousands):
		April 30,
		2014			2013
	Recorded as an increase in deferred tax liabilities—non-current	$	14,424		$	—
	Recorded as a decrease in deferred tax assets—non-current		—			15,973
	Long-term income taxes payable		86,498			90,777
	Balance at end of fiscal year	$	100,922		$	106,750
Schedule of net amounts of interest and penalties and the related foreign exchange gain or loss	'
	The Company recognized the following net amounts of interest and penalties and the related foreign exchange gain or loss for the periods presented (in thousands):
		Year Ended April 30,
		2014			2013			2012
	Recognized interest and penalties, net	$	502		$	1,449		$	865
Schedule of potential interest and penalties accrued	'
	The Company had cumulatively accrued the following amounts for potential interest and penalties as of the dates indicated (in thousands):
		April 30,
		2014			2013
	Balance at end of fiscal year	$	16,691		$	16,189

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	12 Months Ended
	Apr. 30, 2014
Net Income Per Share	'
Schedule of antidilutive securities excluded from computation of income per share	'
		Year Ended April 30,
		2014		2013		2012
	Antidilutive common stock subject to outstanding options		2,510,000		2,957,000		1,222,000
Schedule of computation of basic and diluted earnings per share	'
	The following table sets forth the computation of basic and diluted earnings per share for the periods indicated (in thousands, except per share data):
		Year Ended April 30,
		2014		2013		2012
	Basic:
	Numerator:
	Net income	$	94,997	$	42,902	$	65,849
	Denominator:
	Weighted average common shares for net income per share		55,537		53,529		56,666
	Basic net income per share	$	1.71	$	0.8	$	1.16
	Diluted:
	Numerator:
	Net income	$	94,997	$	42,902	$	65,849
	Denominator:
	Denominator for basic net income per share		55,537		53,529		56,666
	Weighted average effect of dilutive securities:
	Stock options, restricted stock units and employee stock purchase plan shares		506		142		1,567
	Weighted average common shares for diluted net income per share		56,043		53,671		58,233
	Diluted net income per share	$	1.7	$	0.8	$	1.13

Comprehensive_Income_Tables

Comprehensive Income (Tables)	12 Months Ended
	Apr. 30, 2014
Comprehensive Income	'
Schedule of components of other comprehensive income and related tax effects	'
	The following table presents the components of other comprehensive income and related tax effects for the periods indicated (in thousands):
		Year Ended April 30, 2014									Year Ended April 30, 2013								Year Ended April 30, 2012
		Before			Tax			Net of			Before			Tax			Net of		Before			Tax			Net of
		Tax						Tax			Tax						Tax		Tax						Tax
	Translation gains	$	53		$	(18	)	$	35		$	431		$	(151	)	$	280	$	2,893		$	(1,010	)	$	1,883
	Reclassification adjustments for gains on sale of WLCSP		(1,023	)		358			(665	)		—			—			—		—			—			—
	Unrealized gains (losses) on available-for-sale securities		528			(185	)		343			839			(148	)		691		(638	)		299			(339	)
	Reclassification adjustments for losses on available-for-sale securities		(1,641	)		354			(1,287	)		18			(7	)		11		—			—			—
	Total other comprehensive income	$	(2,083	)	$	509		$	(1,574	)	$	1,288		$	(306	)	$	982	$	2,255		$	(711	)	$	1,544
Schedule of components of, and the changes in, accumulated other comprehensive income	'
	The following table presents the components of, and the changes in, accumulated other comprehensive income for the periods indicated (in thousands):
		Balance at			Other			Amounts			Related Tax			Balance at
		May 1, 2012			Comprehensive			Reclassified out			Effects			April 30,
					Income (Loss),			of Accumulated						2013
					Before Tax			Other
								Comprehensive
								Income
	Accumulated translation gains	$	2,756		$	431		$	—		$	(151	)	$	3,036
	Accumulated unrealized gains (losses) on available-for-sale securities, net		214			857			—			(155	)		916
	Total accumulated other comprehensive income	$	2,970		$	1,288		$	—		$	(306	)	$	3,952
		Balance at			Other			Amounts			Related Tax			Balance at
		May 1, 2013			Comprehensive			Reclassified out			Effects			April 30,
					Income (Loss),			of Accumulated						2014
					Before Tax			Other
								Comprehensive
								Income
	Accumulated translation gains	$	3,036		$	53		$	(1,023	)	$	340		$	2,406
	Accumulated unrealized gains (losses) on available-for-sale securities, net		916			528			(1,641	)		169			(28	)
	Total accumulated other comprehensive income	$	3,952		$	581		$	(2,664	)	$	509		$	2,378
Schedule of amounts reclassified out of Accumulated Other Comprehensive Income into the Condensed Consolidated Statements of Income and the associated presentation location	'
	The following table sets forth the amounts reclassified out of Accumulated Other Comprehensive Income into the Consolidated Statements of Income and the associated presentation location, for the periods indicated (in thousands):
				Year Ended April 30,
	Comprehensive Income Components	Location		2014			2013			2012
	Accumulated translation gains	Other income (expense), net		$	(1,023	)	$	—		$	—
	Accumulated unrealized gains (losses) on available-for-sale securities, net	Other income (expense), net			(1,641	)		—			—
		Total amounts reclassified out of Accumulated Other Comprehensive Income		$	(2,664	)	$	—		$	—

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Apr. 30, 2014
Fair Value Measurements	'
Schedule of financial assets and liabilities measured at fair value on a recurring basis comprising types of instruments	'
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were comprised of the following types of instruments as of the date indicated (in thousands):
		April 30, 2014
		Total			Level 1		Level 2			Level 3
	Money market funds	$	57,207		$	57,207	$	—		$	—
	U.S. government debt securities and municipal bonds		17,834			—		17,834			—
	Corporate debt securities/commercial paper		180,764			—		180,764			—
	Total assets	$	255,805		$	57,207	$	198,598		$	—
	Interest rate swap	$	(2,980	)	$	—	$	(2,980	)	$	—
	Total liabilities	$	(2,980	)	$	—	$	(2,980	)	$	—
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were comprised of the following types of instruments as of the date indicated (in thousands):
		April 30, 2013
		Total			Level 1		Level 2			Level 3
	Money market funds	$	44,409		$	44,409	$	—		$	—
	U.S. government debt securities and municipal bonds		1,707			—		1,707			—
	Corporate debt securities/commercial paper		20,457			—		20,457			—
	Equity investment in Tong Hsing		5,313			5,313		—			—
	Total assets	$	71,886		$	49,722	$	22,164		$	—
	Interest rate swaps	$	(4,184	)	$	—	$	(4,184	)	$	—
	Total liabilities	$	(4,184	)	$	—	$	(4,184	)	$	—
Schedule of financial assets and liabilities measured at fair value on a recurring basis presented on the entity's consolidated balance sheets	'
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were presented on the Company's Consolidated Balance Sheets as of the date indicated (in thousands):
		April 30, 2014
		Total			Level 1		Level 2			Level 3
	Cash equivalents	$	102,812		$	57,207	$	45,605		$	—
	Short-term investments		152,993			—		152,993			—
	Total assets	$	255,805		$	57,207	$	198,598		$	—
	Interest rate swap	$	(2,980	)	$	—	$	(2,980	)	$	—
	Total liabilities	$	(2,980	)	$	—	$	(2,980	)	$	—
	The following table presents the Company's financial assets and liabilities that are measured at fair value on a recurring basis which were presented on the Company's Consolidated Balance Sheets as of the date indicated (in thousands):
		April 30, 2013
		Total			Level 1		Level 2			Level 3
	Cash equivalents	$	44,409		$	44,409	$	—		$	—
	Short-term investments		22,164			—		22,164			—
	Long-term investments		5,313			5,313		—			—
	Total assets	$	71,886		$	49,722	$	22,164		$	—
	Interest rate swaps	$	(4,184	)	$	—	$	(4,184	)	$	—
	Total liabilities	$	(4,184	)	$	—	$	(4,184	)	$	—

Employee_Stock_Purchase_Equity1

Employee Stock Purchase, Equity Incentive and Stock Option Plans (Tables)	12 Months Ended
	Apr. 30, 2014
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'
Schedule of equity incentive and stock-based compensation plans	'
	The Company's equity incentive and stock-based compensation plans as of April 30, 2014 are summarized as follows (in thousands):
	Name of Plan	Shares			Shares			Options			Restricted
		Authorized			Available			Outstanding			Stock Units
					for Grant						Outstanding
	2000 Stock Plan		—			—			1,358			—
	2000 Director Option Plan		—			—			88			—
	2007 Equity Incentive Plan		18,100			6,921			2,557			2,732
	Total		18,100			6,921			4,003			2,732
Summary of equity award activities under the 2000 Stock Plan, the 2000 Director Option Plan and the 2007 Plan	'
					Options Outstanding						Restricted			Restricted
											Stock Units			Stock Units
											Outstanding
		Shares			Number of			Weighted			Number of			Weighted
		Available			Shares			Average			Shares			Average
		For						Exercise						Grant Date
		Grant						Price						Fair Market
								Per Share						Value Per
														Share
		(in thousands)			(in thousands)						(in thousands)
	Balance at May 01, 2012		2,717			3,936		$	16.31			2,005		$	16.81
	2007 Plan share increased		7,200			—			—			—			—
	Stock options granted		(600	)		600			34.65			—			—
	Stock options exercised		—			(885	)		15.41			—			—
	Stock options expired or forfeited		28			(81	)		20.42			—			—
	Restricted stock units granted(1)		(2,088	)		—			—			1,305			32.27
	Restricted stock units vested(1)		—			—			—			(1,116	)		14.84
	Restricted stock units expired or forfeited(1)		231			—			—			(141	)		23.71
	Balance at April 30, 2012		7,488			3,570			19.53			2,053			27.24
	Stock options granted		(644	)		644			13.53			—			—
	Stock options exercised		—			(137	)		7.95			—			—
	Stock options expired or forfeited		2			(83	)		20.8			—			—
	Restricted stock units granted(1)		(2,446	)		—			—			1,528			13.39
	Restricted stock units vested(1)		—			—			—			(903	)		24.39
	Restricted stock units expired or forfeited(1)		359			—			—			(224	)		20.26
	Balance at April 30, 2013		4,759			3,994			18.93			2,454			20.3
	2007 Plan amendment		4,900			—			—			—			—
	Stock options granted		(692	)		692			18.47			—			—
	Stock options exercised		—			(465	)		14.66			—			—
	Stock options expired or forfeited		171			(218	)		24.66			—			—
	Restricted stock units granted(1)		(2,627	)		—			—			1,642			18.36
	Restricted stock units vested(1)		—			—			—			(1,110	)		22.02
	Restricted stock units expired or forfeited(1)		410			—			—			(254	)		18.82
	Balance at April 30, 2014—shares available for grant		6,921			—			—			—			—
	Balance at April 30, 2014—options		—			4,003			19.04			—			—
	Balance at April 30, 2014—restricted stock units		—			—			—			2,732			18.57
	Exercisable at April 30, 2014		—			2,806			18.94			—			—
	Vested and expected to vest at April 30, 2014—options		—			3,894		$	19.06			—			—
	Vested and expected to vest at April 30, 2014—restricted stock units		—			—			—			2,430		$	18.57
	-1
	Shares subject to awards granted for less than fair market value on the date of grant count against the share reserve as two shares for every one share subject to such an award. When a share is returned to the plan, two shares will be credited back to the reserve. With the approval of the Company's stockholders in September 2009, the Company modified certain terms of the 2007 Plan. Specifically, for restricted stock units granted after September 2009, the grant will count against the share reserve as 1.6 shares for every one share granted. When a share is returned to the plan which was granted after September 2009, 1.6 shares will be credited back to the reserve.
Summary of information regarding options outstanding	'
		Options Outstanding												Options Exercisable
	Range of Exercise Prices	Options			Weighted			Weighted			Aggregate			Options			Weighted			Weighted		Aggregate
		Outstanding			Average			Average			Intrinsic			Vested and			Average			Average		Intrinsic
					Remaining			Exercise			Value			Exercisable			Remaining			Exercise		Value
					Contractual			Price									Contractual			Price
					Life												Life
		(in thousands)			(in years)						(in thousands)			(in thousands)			(in years)					(in thousands)
	$  5.82 - $13.34		875			5.01		$	12.34						570					$	11.8
	$13.61 - $16.69		938			2.91			15.51						889						15.53
	$16.85 - $18.47		964			4.9			18.04						305						17.11
	$18.77 - $25.56		718			2.57			21.98						693						21.98
	$34.80 - $34.80		508			4.17			34.8						349						34.8
	$  5.82 - $34.84		4,003			3.95		$	19.04		$	11,589			2,806			3.26		$	18.94	$	8,792
Schedule of the total intrinsic value of options exercised and restricted stock units vested, and the total cash received from employee stock option exercises	'
	The total intrinsic value of options exercised, the total intrinsic value of restricted stock units vested and the total cash received from employees as a result of employee stock option exercises during the periods indicated were as follows (in thousands):
		April 30,
		2014			2013
	Total intrinsic value of options exercised	$	1,784		$	1,015
	Total intrinsic value of restricted stock units vested		20,330			12,096
	Total cash received from employees as a result of employee stock option exercises	$	6,825		$	1,085
Schedule of unrecognized compensation expense and the weighted average period over which the Company expects to recognize compensation	'
	Unrecognized compensation expense and the weighted average period over which the Company expects to recognize such compensation as of the dates indicated were as follows (dollars in thousands):
		April 30,
		2014			2013
	Unvested stock options:
	Unrecognized compensation expense, net of forfeitures	$	8,403		$	8,444
	Weighted average period (years)		2.5			2.5
	Unvested restricted stock units:
	Unrecognized compensation expense, net of forfeitures	$	28,749		$	28,818
	Weighted average period (years)		1.7			1.7
	2009 Purchase Plan:
	Unrecognized compensation expense	$	3,396		$	1,063
	Weighted average period (years)		1.1			0.6
Schedule of per share weighted average estimated grant date fair value for employee options granted	'
		Year Ended April 30,
		2014			2013			2012
	Per share weighted average estimated grant date fair value	$	7.92		$	6.36		$	15.37
Schedule of weighted average assumptions used in the estimated fair value calculations for stock options granted and the employee stock purchase plan	'
		Employee Stock									Employee Stock
		Option Plans									Purchase Plan
		Year Ended									Year Ended
		April 30,									April 30,
		2014			2013			2012			2014			2013			2012
	Risk-free interest rate		1	%		0.6	%		1.3	%		0.1	%		0.1	%		0.1	%
	Expected term of options (in years)		4.59			4.3			4.2			0.5			0.5			0.5
	Expected volatility		51	%		60	%		55	%		46	%		63	%		53	%
	Expected dividend yield		0	%		0	%		0	%		0	%		0	%		0	%
Schedule of weighted average fair value of rights issued under employee stock purchase plan	'
		Year Ended April 30,
		2014			2013			2012
	Per share weighted average estimated fair value of rights issued	$	5.83		$	6.06		$	5.54

Risks_and_Uncertainties_Tables

Risks and Uncertainties (Tables)	12 Months Ended
	Apr. 30, 2014
Risks and Uncertainties	'
Schedule of significant customers of the Company as a percentage of revenues	'
		Year Ended April 30,
		2014			2013			2012
	Percentage of revenues:
	Customer A		13.8	%		10.7	%		*	%
	Customer B		12.5			10.3			*
	Customer C		11			11.7			13.5
	Customer D		*	%		18	%		15.2	%
	*
	Less than ten percent of revenues.
Schedule of significant customers of the Company as a percentage of net accounts receivable	'
		April 30,
		2014			2013
	Percentage of accounts receivable, net:
	Customer A		17	%		*	%
	Customer B		12.7			15.1
	Customer C		10.4			*
	Customer D		*			15.3
	Customer E		*	%		11.1	%
	*
	Less than ten percent of accounts receivable, net.

Segment_and_Geographic_Informa1

Segment and Geographic Information (Tables)	12 Months Ended
	Apr. 30, 2014
Segment and Geographic Information	'
Schedule of revenues by customer segment	'
		Year Ended April 30,
		2014			2013			2012
	OEMs and VARs		81.2	%		81.2	%		78.1	%
	Distributors		18.8			18.8			21.9
	Total		100	%		100	%		100	%
Schedule of revenues by geography based on the country or region in which the Company's customers issue their purchase orders	'
	The revenues by geography in the following table are based on the country or region in which the Company's customers issue their purchase orders for the periods presented (in thousands):
		Year Ended April 30,
		2014			2013			2012
	China	$	1,122,802		$	955,378		$	520,452
	South Korea		158,693			275,105			147,390
	Japan		89,311			57,604			46,108
	Taiwan		23,748			27,120			18,253
	United States		4,781			3,997			61,766
	All other		54,594			88,725			103,761
	Total	$	1,453,929		$	1,407,929		$	897,730
Schedule of the Company's long-lived assets, including its property, plant and equipment, net, long-term investments, land-use rights and other long-term assets	'
	The Company's long-lived assets, including its property, plant and equipment, net, long-term investments, land-use rights and other long-term assets are located in the following countries as of the dates indicated (in thousands):
		April 30,
		2014			2013
	China	$	162,207		$	139,482
	Taiwan		126,820			137,359
	United States		50,552			50,903
	All other		623			811
	Total	$	340,202		$	328,555

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Apr. 30, 2014
Commitments and Contingencies	'
Schedule of future minimum lease commitments under operating leases	'
	At April 30, 2014, future minimum lease commitments under operating leases are as follows (in thousands):
	Years Ended April 30,
	2015	$	6,012
	2016		5,378
	2017		2,078
	2018		816
	2019		796
	Thereafter		1,320
	Total	$	16,400
Schedule of rental expenses under all operating leases	'
	The following table presents rental expenses under all operating leases during the periods presented (in thousands):
		Year Ended April 30,
		2014		2013		2012
	Rental expenses under operating leases	$	9,775	$	11,491	$	9,293

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Apr. 30, 2014
Related Party Transactions	'
Schedule of related party transactions and balances	'
	The following table presents the amounts paid for services provided by related parties and the balances payable for the periods indicated (in thousands):
			Year Ended April 30,
	Related Party	Description	2014		2013		2012
	VisEra	Purchases of color filter and other manufacturing services	$	119,919	$	166,100	$	121,008
		Rent and other services(1)	$	3	$	3,664	$	1,972
		Balance payable at year end, net	$	19,160	$	28,024	$	17,329
	WLCSP	Purchases of packaging services	$	2,097	$	—	$	—
		Balance payable at year end, net	$	1,156	$	—	$	—
	-1
	The Company leased manufacturing floor space from VisEra from November 2011 to May 2013.

Basis_of_Presentation_Details

Basis of Presentation (Details) (USD $)	Apr. 30, 2014	Apr. 30, 2013	Dec. 31, 2000	Jan. 31, 2007	Jul. 31, 2011
	agreement		OSC	OTC	OST
				sqft	sqft
Reclassifications	'	'	'	'	'
Land-use rights, net	$2,180,000	$2,236,000	'	'	'
Number of land-use rights agreements	3	'	'	'	'
Land-use rights, gross	'	'	$800,000	$600,000	$1,000,000
Land-use rights, amortization period	'	'	'40 years	'50 years	'50 years
Area of land (in square feet)	'	'	'	323,000	113,175

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
	contract
Foreign Currency Translation	'	'	'
Remeasurement losses	$1,500,000	$405,000	'
Remeasurement gains	'	'	$117,000
Fair Value of Financial Instruments	'	'	'
Number of interest rate swap arrangements outstanding	1	'	'

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 2)	12 Months Ended
	Apr. 30, 2014
Buildings	'
Property, Plant and Equipment	'
Estimated useful life	'40 years
Building/leasehold improvements	'
Property, Plant and Equipment	'
Estimated useful life	'20 years
Machinery and equipment | Minimum	'
Property, Plant and Equipment	'
Estimated useful life	'2 years
Machinery and equipment | Maximum	'
Property, Plant and Equipment	'
Estimated useful life	'10 years
Furniture and fixtures | Minimum	'
Property, Plant and Equipment	'
Estimated useful life	'3 years
Furniture and fixtures | Maximum	'
Property, Plant and Equipment	'
Estimated useful life	'7 years

Summary_of_Significant_Account5

Summary of Significant Accounting Policies (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Inventories	'	'	'
Time period of forecasted sales used to compute the provision for inventory obsolescence	'12 months	'	'
Research, Development and Related	'	'	'
Research and development expenses	$114,224	$109,026	$106,587

ShortTerm_Investments_Details

Short-Term Investments (Details) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Available-for-sale securities	'	'	'
Amortized Cost	$153,034,000	$22,170,000	'
Gross Unrealized Gains	7,000	'	'
Gross Unrealized Losses	-48,000	-6,000	'
Fair Value	152,993,000	22,164,000	'
Contractual maturity dates	'	'	'
Contractual maturity dates, less than one year	142,758,000	20,764,000	'
Contractual maturity dates, one to two years	10,235,000	'	'
Contractual maturity dates, two to twenty-three years	'	1,400,000	'
Fair Value	152,993,000	22,164,000	'
Available-for-sale securities, other disclosures	'	'	'
Proceeds from sale of available-for-sale investments, primarily marketable debt instruments	35,500,000	275,300,000	151,600,000
Municipal bonds	'	'	'
Available-for-sale securities	'	'	'
Amortized Cost	6,168,000	1,707,000	'
Gross Unrealized Gains	1,000	'	'
Gross Unrealized Losses	-2,000	'	'
Fair Value	6,167,000	1,707,000	'
Contractual maturity dates	'	'	'
Fair Value	6,167,000	1,707,000	'
Corporate debt securities/commercial paper	'	'	'
Available-for-sale securities	'	'	'
Amortized Cost	146,866,000	20,463,000	'
Gross Unrealized Gains	6,000	'	'
Gross Unrealized Losses	-46,000	-6,000	'
Fair Value	146,826,000	20,457,000	'
Contractual maturity dates	'	'	'
Fair Value	$146,826,000	$20,457,000	'

Supplemental_Balance_Sheet_Acc2

Supplemental Balance Sheet Account Information (in thousands) (Details) (USD $)	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
In Thousands, unless otherwise specified
Cash and cash equivalents:	'	'	'	'
Cash	$195,141	$145,762	'	'
Money market funds and U.S. government bonds	102,811	44,409	'	'
Cash and cash equivalents	297,952	190,171	290,492	379,379
Accounts receivable, net:	'	'	'	'
Accounts receivable	176,576	172,833	'	'
Less: Allowance for doubtful accounts	-998	-945	'	'
Allowance for sales returns	-3,106	-5,371	'	'
Accounts receivable, net	172,472	166,517	'	'
Inventories:	'	'	'	'
Work in progress	107,621	213,095	'	'
Finished goods	163,314	217,220	'	'
Inventories	270,935	430,315	'	'
Prepaid expenses and other current assets:	'	'	'	'
Prepaid expenses	4,285	7,974	'	'
Deposits and other	1,284	3,907	'	'
Interest receivable	1,007	101	'	'
Prepaid expenses and other current assets	6,576	11,982	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	261,102	247,026	'	'
Less: Accumulated depreciation and amortization	-107,310	-88,632	'	'
Property, plant and equipment, net	153,792	158,394	'	'
Other long-term assets:	'	'	'	'
Deferred tax assets - non-current	528	6,251	'	'
Land-use rights	2,180	2,236	'	'
Other long-term assets	29,821	28,179	'	'
Total other long-term assets	32,529	36,666	'	'
Accrued expenses and other current liabilities:	'	'	'	'
Due to VisEra for acquisition of production operations	'	9,000	'	'
Deferred tax liabilities - current	144	'	'	'
Employee compensation	15,176	12,856	'	'
Third party commissions	380	850	'	'
Professional services	2,270	2,176	'	'
Noncancelable purchase commitments	647	4,817	'	'
Rebates	1,511	2,557	'	'
Other	11,831	8,018	'	'
Accrued expenses and other current liabilities	31,959	40,274	'	'
Other long-term liabilities:	'	'	'	'
Interest rate swap	2,980	4,184	'	'
Deferred tax liabilities - non-current	3,731	'	'	'
Other	5,107	434	'	'
Other long-term liabilities	11,818	4,618	'	'
Land	'	'	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	13,000	13,000	'	'
Buildings	'	'	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	82,547	57,246	'	'
Buildings/leasehold improvements	'	'	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	29,123	24,659	'	'
Machinery and equipment	'	'	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	119,762	102,429	'	'
Furniture and fixtures	'	'	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	5,002	5,013	'	'
Software	'	'	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	8,774	6,954	'	'
Construction in progress	'	'	'	'
Property, plant and equipment, net:	'	'	'	'
Property, plant and equipment, gross	$2,894	$37,725	'	'

LongTerm_Investments_Details

Long-Term Investments (Details) (USD $)

12 Months Ended

1 Months Ended

3 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

1 Months Ended

3 Months Ended

11 Months Ended

12 Months Ended

3 Months Ended

1 Months Ended

12 Months Ended

3 Months Ended

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Apr. 30, 2003

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2013

Feb. 29, 2012

Jul. 31, 2013

Apr. 30, 2014

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Oct. 31, 2011

Jun. 30, 2011

Apr. 30, 2014

Apr. 30, 2014

Jan. 31, 2014

Sep. 30, 2010

31-May-10

31-May-07

Jan. 31, 2014

Mar. 31, 2014

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Apr. 30, 2010

Jan. 31, 2014

Jan. 31, 2014

Jan. 31, 2014

Jun. 30, 2011

Jun. 30, 2010

Dec. 31, 2009

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Oct. 31, 2013

Oct. 31, 2013

Nov. 30, 2009

XinTec, Inc. ("XinTec")

XinTec, Inc. ("XinTec")

XinTec, Inc. ("XinTec")

Phostek, Inc. ("Phostek")

Phostek, Inc. ("Phostek")

Phostek, Inc. ("Phostek")

VisEra Technologies Company, Ltd. ("VisEra")

VisEra Technologies Company, Ltd. ("VisEra")

VisEra Technologies Company, Ltd. ("VisEra")

VisEra Technologies Company, Ltd. ("VisEra")

VisEra Technologies Company, Ltd. ("VisEra")

VisEra Technologies Company, Ltd. ("VisEra")

VisEra Holding Company ("VisEra Cayman")

VisEra Holding Company ("VisEra Cayman")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

China WLCSP Limited ("WLCSP")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

Tong Hsing Electronic Industries, Limited ("Tong Hsing")

ImPac Technology Co., Ltd. ("ImPac")

Other income (expense), net

CameraCube production operations

XinTec, Inc. ("XinTec")

Change in interest gain

Gain from share sale

Other income (expense), net

Other income (expense), net

Long-term investment disclosures

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term investments

$154,409,000

$139,746,000

'

'

$4,661,000

$4,661,000

$2,000,000

$2,000,000

'

$115,943,000

$115,943,000

$105,233,000

'

'

'

'

'

'

'

'

'

'

'

$33,805,000

$22,539,000

'

'

'

'

'

'

'

'

'

$5,313,000

'

'

'

'

Percentage of equity ownership

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

49.10%

'

'

18.70%

'

20.00%

'

'

13.30%

'

'

19.70%

'

'

'

'

'

'

'

'

'

'

'

25.70%

Final payment for acquisition of production operation from VisEra

4,500,000

'

'

'

'

'

'

'

'

4,500,000

'

'

'

'

42,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional contingent consideration

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due to VisEra for acquisition of production operations

'

9,000,000

'

'

'

'

'

'

'

'

'

9,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reduction in consideration for production operations from VisEra

'

'

'

'

'

'

'

'

'

4,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Post-acquisition gain

'

'

'

'

'

'

'

'

'

3,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity method elimination

'

'

'

'

'

'

'

'

'

1,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividend payments received from investee

'

'

'

'

'

'

'

'

'

'

'

13,760,000

'

'

'

'

'

'

'

'

'

'

'

830,000

890,000

852,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividend payments receivable from investee

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity income

19,459,000

20,014,000

10,403,000

'

'

'

'

'

'

'

10,710,000

20,274,000

8,835,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net effect on Cost of revenues, after the elimination of unrealized intercompany profits

'

'

'

'

'

'

'

'

'

'

17,228,000

15,752,000

7,326,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income distribution

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity income

4,009,000

3,832,000

3,066,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,009,000

3,762,000

3,154,000

3,066,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment acquired (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,500,000

'

'

'

'

'

'

'

'

'

115,481

95,570

996,250

'

'

'

'

'

'

Purchase amount of equity method investment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares outstanding

56,081,586

53,975,195

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

226,700,000

'

180,000,000

'

226,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ownership interest in outstanding shares (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30,300,000

'

35,400,000

'

30,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

37,200,000

9,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

IPO price (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$3.14

'

'

'

$3.14

'

$5.50

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares sold as selling shareholder in initial public offering

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain on the sale of shares

23,802,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

14,100,000

9,700,000

23,800,000

'

'

'

'

'

'

'

'

'

Prepaid expenses and other current assets

6,576,000

11,982,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,100,000

'

'

'

15,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cumulative translation adjustment reclassified from accumulated other comprehensive income

665,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase of long-term investment

'

'

'

2,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ownership percentage

'

'

'

'

4.20%

'

'

'

'

'

'

'

'

'

'

'

15.80%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beneficial ownership percentage

'

'

'

'

11.90%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of equity ownership

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.80%

'

'

'

0.70%

'

'

Basis difference between investment amount and book value of underlying assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,200,000

'

'

'

'

'

'

Additional contributions to other investment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

421,000

282,000

'

'

'

'

'

'

'

Gain on sale of investment

1,990,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,000,000

'

Unrealized holding gains (losses)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

566,000

859,000

-328,000

'

'

'

Impairment charge

'

'

'

'

'

'

'

'

2,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating data:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

'

131,850,000

169,969,000

125,777,000

'

'

'

'

'

'

'

'

'

75,480,000

'

57,340,000

47,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross profit

'

'

'

'

'

'

'

'

'

'

50,426,000

58,531,000

32,607,000

'

'

'

'

'

'

'

'

'

40,909,000

'

31,348,000

24,854,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Income from operations

'

'

'

'

'

'

'

'

'

'

40,312,000

47,512,000

48,818,000

'

'

'

'

'

'

'

'

'

26,428,000

'

23,742,000

18,458,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

'

'

'

'

'

'

'

'

'

'

32,121,000

31,921,000

32,482,000

'

'

'

'

'

'

'

'

'

23,055,000

'

20,520,000

16,638,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance sheet data:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current assets

'

'

'

'

'

'

'

'

'

189,399,000

189,399,000

168,343,000

'

'

'

'

'

'

'

'

'

'

221,547,000

'

52,985,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term assets

'

'

'

'

'

'

'

'

'

112,956,000

112,956,000

132,633,000

'

'

'

'

'

'

'

'

'

'

134,482,000

'

81,733,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current liabilities

'

'

'

'

'

'

'

'

'

38,086,000

38,086,000

68,854,000

'

'

'

'

'

'

'

'

'

'

96,570,000

'

12,204,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,000

'

3,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Undistributed earnings of investees

$66,772,000

$49,830,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Details) (USD $)

12 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Jan. 31, 2014

Jan. 31, 2014

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Acquired patent portfolio

Acquired patent portfolio

Core technology

Core technology

Patents and licenses

Patents and licenses

Patents and licenses

Patents and licenses

Patents and licenses

Trademarks and tradenames

Trademarks and tradenames

Customer relationships

Customer relationships

Amortization of finite Lived intangibles excluding acquired patent portfolio

Amortization of finite Lived intangibles excluding acquired patent portfolio

Amortization of finite Lived intangibles excluding acquired patent portfolio

Cost of revenues

Change to carrying value of goodwill

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Changes to carrying value

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning balance

10,227,000

10,227,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ending balance

10,227,000

10,227,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Intangible assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total cash transaction amount

'

'

'

'

'

'

'

'

'

25,400,000

'

'

'

'

'

'

'

'

Present value of payments required under payment schedule

'

'

'

'

'

'

'

'

'

24,600,000

'

'

'

'

'

'

'

'

Cumulative cost related to prior years recorded

'

'

'

'

'

'

'

'

'

'

2,700,000

'

'

'

'

'

'

'

Additions to intangible assets

'

'

'

'

'

'

21,900,000

'

'

'

'

'

'

'

'

'

'

'

Amortization period of intangible assets

'

'

'

'

'

'

'9 years

'

'

'

'

'

'

'

'

'

'

'

Finite-lived intangible assets, Cost

138,906,000

117,000,000

65,000,000

65,000,000

36,100,000

36,100,000

36,066,000

14,160,000

'

'

'

1,400,000

1,400,000

340,000

340,000

'

'

'

Finite-lived intangible assets, Accumulated Amortization

72,689,000

60,196,000

28,631,000

19,345,000

27,980,000

25,649,000

14,438,000

13,596,000

'

'

'

1,400,000

1,400,000

240,000

206,000

'

'

'

Finite-lived intangible assets, Net Book Value

66,217,000

56,804,000

36,369,000

45,655,000

8,120,000

10,451,000

21,628,000

564,000

'

'

'

'

'

100,000

134,000

'

'

'

Amortization of intangible assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of intangibles

'

'

'

'

'

'

9,286,000

9,286,000

9,286,000

'

'

'

'

'

'

3,207,000

3,638,000

2,778,000

Expected future annual amortization of intangible assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2015

13,929,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2016

13,753,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2017

13,627,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2018

12,546,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2019

3,234,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Thereafter

9,128,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total

$66,217,000

$56,804,000

$36,369,000

$45,655,000

$8,120,000

$10,451,000

$21,628,000

$564,000

'

'

'

'

'

$100,000

$134,000

'

'

'

Borrowing_Arrangements_and_Rel2

Borrowing Arrangements and Related Derivative Instruments (Details)

0 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

Mar. 16, 2007

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Apr. 30, 2014

Apr. 30, 2013

Mar. 16, 2007

Apr. 30, 2014

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2014

Jul. 31, 2008

Apr. 30, 2014

Mar. 16, 2007

building

USD ($)

USD ($)

Other long-term liabilities

Other long-term liabilities

Other income (expense), net

Other income (expense), net

Other income (expense), net

Mortgage loan

Mortgage loan

Mortgage loan

Mortgage loan

Construction loan

Construction loan

Construction loan

Construction loan

Term loan

Term loan

Term loan

loan

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

LIBOR

USD ($)

USD ($)

OmniVision Technologies (Shanghai) Co., Ltd.

OmniVision Technologies (Shanghai) Co., Ltd.

USD ($)

USD ($)

contract

USD ($)

CNY

Borrowing arrangements

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total

'

$35,832,000

$39,478,000

'

'

'

'

'

$23,653,000

$24,207,000

'

'

$12,179,000

$15,271,000

'

'

'

'

'

Less: amount due within one year

'

-3,802,000

-3,769,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Non-current portion of long-term debt

'

32,030,000

35,709,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate debt maturities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2015

'

3,802,000

'

'

'

'

'

'

554,000

'

'

'

3,248,000

'

'

'

'

'

'

2016

'

7,049,000

'

'

'

'

'

'

554,000

'

'

'

6,495,000

'

'

'

'

'

'

2017

'

24,981,000

'

'

'

'

'

'

22,545,000

'

'

'

2,436,000

'

'

'

'

'

'

Total

'

35,832,000

39,478,000

'

'

'

'

'

23,653,000

24,207,000

'

'

12,179,000

15,271,000

'

'

'

'

'

Number of buildings purchased against Loan and Security Agreement with a domestic bank

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount

'

'

'

'

'

'

'

'

'

'

27,900,000

'

'

'

'

'

'

'

'

Aggregate maximum principal amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,000,000

Amount borrowed (repaid)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,000,000

'

'

Reference rate of debt

'

'

'

'

'

'

'

'

'

'

'

'LIBOR

'

'

'

'

'

'

'

Basis points added to reference rate of debt (as a percent)

'

'

'

'

'

'

'

'

'

'

'

0.90%

'

'

'

'

'

'

'

Interest rate on debt (as a percent)

'

'

'

'

'

'

'

'

1.10%

1.10%

'

'

'

'

5.90%

5.90%

'

'

'

Interest rates swap period

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

Stated interest rate on debt (as a percent)

'

'

'

'

'

'

'

'

5.30%

'

'

'

'

'

'

'

'

4.30%

'

Effective interest rate on debt (as a percent)

'

'

'

'

'

'

'

'

6.20%

'

'

'

'

'

'

'

'

5.50%

'

Amount outstanding under line of credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,200,000

75,000,000

'

'

'

Location of amounts recognized in Consolidated Statements of Income and amount of gains (losses):

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain (loss) on interest rate swap recorded in other income (expense), net

'

'

'

'

'

1,204,000

625,000

-880,000

'

'

'

'

'

'

'

'

'

'

'

Location of amounts on Consolidated Balance Sheets and fair values:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate swap recorded in Other long-term liabilities

'

$2,980,000

$4,184,000

$2,980,000

$4,184,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative Instruments and Hedging Activities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate swap, number (in contracts)

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of loans with interest rate swaps

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Current:	'	'	'
Federal	$5,802,000	$7,746,000	$3,068,000
State	17,000	16,000	16,000
Foreign	-4,315,000	3,863,000	808,000
Total current	1,504,000	11,625,000	3,892,000
Deferred:	'	'	'
Federal	6,066,000	-2,261,000	3,356,000
State	1,832,000	-837,000	-449,000
Foreign	530,000	-1,265,000	'
Total deferred	8,428,000	-4,363,000	2,907,000
Total provision	9,932,000	7,262,000	6,799,000
Income (loss) before provision for income taxes	'	'	'
United States	-16,581,000	-20,996,000	2,280,000
International	121,510,000	71,160,000	70,368,000
Income before income taxes	104,929,000	50,164,000	72,648,000
Differences in the provision for income taxes and the amount computed by applying the U.S. federal income tax rate	'	'	'
U.S. federal income tax rate (as a percent)	35.00%	'	'
Provision based on statutory federal income tax rate	36,725,000	17,557,000	25,426,000
State income tax expense (benefit), net of federal rate tax benefit	1,849,000	-868,000	-481,000
Foreign rate differential	-32,481,000	-14,843,000	-21,349,000
Non-deductible stock-based compensation	6,678,000	7,412,000	5,583,000
Tax credits	-3,691,000	-3,409,000	-2,979,000
Prior year adjustment	'	1,184,000	'
Other	852,000	229,000	599,000
Total provision	9,932,000	7,262,000	6,799,000
Other disclosures of the provision for (benefit from) income taxes	'	'	'
Combined U.S. federal and state statutory rate (as a percent)	40.00%	40.00%	40.00%
Reduction in unrecognized tax benefits, including the related interest and penalties, due to lapse of applicable statute of limitations in a foreign jurisdiction	8,507,000	3,123,000	2,667,000
Deferred tax assets:	'	'	'
Tax credits	28,589,000	23,832,000	'
Net operating loss	3,099,000	1,612,000	'
Stock-based compensation expenses	7,406,000	7,230,000	'
Unrealized loss on interest rate swap	1,044,000	1,694,000	'
Fixed assets	533,000	1,355,000	'
Accruals, reserves and other	6,174,000	6,105,000	'
Gross deferred tax assets	46,845,000	41,828,000	'
Valuation allowance	-17,326,000	-12,116,000	'
Deferred tax assets	29,519,000	29,712,000	'
Deferred tax liabilities:	'	'	'
Undistributed earnings of non-US equity investees not permanently reinvested	-25,771,000	-17,735,000	'
Other	-2,122,000	-1,698,000	'
Deferred tax liabilities	-27,893,000	-19,433,000	'
Net deferred tax assets	1,626,000	10,279,000	'
Deferred tax assets and liabilities, Other disclosures	'	'	'
Unrecognized deferred tax benefits related to excess tax benefits from stock-based awards	18,700,000	21,100,000	'
Foreign	'	'	'
Other disclosures of the provision for (benefit from) income taxes	'	'	'
Reduction in unrecognized tax benefits, including the related interest and penalties, due to lapse of applicable statute of limitations in a foreign jurisdiction	$8,900,000	'	'

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014
		California	California	U.S. federal
		Research and development	Research and development	Research and development
Tax credits	'	'	'	'
Deferred tax assets primarily pertaining to tax credit carryovers	'	$17.30	$12.10	'
Tax credits	'	35.3	'	31.5
Amount of additional interest accrued by the Company related to the unrecognized tax benefits	$496.20	'	'	'

Income_Taxes_Details_3

Income Taxes (Details 3) (USD $)	Apr. 30, 2014
In Millions, unless otherwise specified
U.S. federal	'
Operating loss carryforwards	'
Net operating loss carryforwards	$3.40
California	'
Operating loss carryforwards	'
Net operating loss carryforwards	$31.70

Income_Taxes_Details_4

Income Taxes (Details 4) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Reconciliation of the beginning balance and the ending balance of gross unrecognized tax benefits, excluding interest and penalties	'	'	'
Balance at beginning of fiscal year	$90,561,000	$87,433,000	$85,734,000
Increases in balances related to tax positions taken during current year	4,345,000	6,288,000	4,536,000
Decreases as a result of lapses of the applicable statute of limitations	-8,507,000	-3,123,000	-2,667,000
Increases in balances related to tax positions taken during prior years	1,363,000	422,000	89,000
Decreases in balances related to tax positions taken during prior years	-3,531,000	-459,000	-259,000
Balance at end of fiscal year	84,231,000	90,561,000	87,433,000
Reconciliation of the gross unrecognized tax benefits, including interest and penalties	'	'	'
Recorded as an increase in deferred tax liabilities - non-current	14,424,000	'	'
Recorded as a decrease in deferred tax assets - non-current	'	15,973,000	'
Long-term income taxes payable	86,498,000	90,777,000	'
Balance at end of fiscal year	100,922,000	106,750,000	'
Net amounts of interest and penalties and the related foreign exchange gain or loss	'	'	'
Recognized interest and penalties, net	502,000	1,449,000	865,000
Reversal of accrued interest and penalties related to the reductions to unrecognized tax benefits as a result of lapses of the statute of limitations	394,000	463,000	'
Cumulatively accrued the following amounts for potential interest and penalties as of the dates indicated	'	'	'
Balance at end of fiscal year	16,691,000	16,189,000	'
Unrecognized tax benefits, other disclosures	'	'	'
Total amount of unrecognized tax benefits, net of federal benefit, if recognized, would affect the effective tax rate	95,400,000	'	'
Anticipated decrease in gross unrecognized tax benefits due to the lapse of the applicable statutes of limitations in certain foreign jurisdictions over the next 12 months	15,100,000	'	'
Singapore Economic Development Board	'	'	'
Reconciliation of the beginning balance and the ending balance of gross unrecognized tax benefits, excluding interest and penalties	'	'	'
Decreases as a result of lapses of the applicable statute of limitations	-8,900,000	'	'
Income tax holiday	'	'	'
Reduction in overall provision for income taxes due to partial tax holiday	$22,600,000	'	'
Increase in diluted net income per share due to partial tax holiday (in dollars per share)	$0.40	'	'

Net_Income_Per_Share_Details

Net Income Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Net Income Per Share	'	'	'	'	'	'	'	'	'	'	'
Antidilutive common stock subject to outstanding options (in shares)	'	'	'	'	'	'	'	'	2,510,000	2,957,000	1,222,000
Basic Numerator:	'	'	'	'	'	'	'	'	'	'	'
Net income	$15,073	$30,560	$26,303	$23,061	$8,922	$21,308	$10,345	$2,327	$94,997	$42,902	$65,849
Basic Denominator:	'	'	'	'	'	'	'	'	'	'	'
Weighted average common shares for net income per share	56,042,000	55,913,000	55,584,000	54,611,000	53,943,000	53,830,000	53,514,000	52,830,000	55,537,000	53,529,000	56,666,000
Basic net income per share (in dollars per share)	$0.27	$0.55	$0.47	$0.42	$0.17	$0.40	$0.19	$0.04	$1.71	$0.80	$1.16
Diluted Numerator:	'	'	'	'	'	'	'	'	'	'	'
Net income	$15,073	$30,560	$26,303	$23,061	$8,922	$21,308	$10,345	$2,327	$94,997	$42,902	$65,849
Diluted Denominator:	'	'	'	'	'	'	'	'	'	'	'
Denominator for basic net income per share	56,042,000	55,913,000	55,584,000	54,611,000	53,943,000	53,830,000	53,514,000	52,830,000	55,537,000	53,529,000	56,666,000
Weighted average effect of dilutive securities:	'	'	'	'	'	'	'	'	'	'	'
Stock options, restricted stock units and employee stock purchase plan shares	'	'	'	'	'	'	'	'	506,000	142,000	1,567,000
Weighted average common shares for diluted net income per share	56,882,000	56,186,000	55,732,000	55,344,000	54,061,000	53,930,000	53,675,000	52,865,000	56,043,000	53,671,000	58,233,000
Diluted net income per share (in dollars per share)	$0.26	$0.54	$0.47	$0.42	$0.17	$0.40	$0.19	$0.04	$1.70	$0.80	$1.13

Comprehensive_Income_Details

Comprehensive Income (Details) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Before Tax	'	'	'
Translation gains	$53,000	$431,000	$2,893,000
Reclassification adjustments for gains on sale of WLCSP	-1,023,000	'	'
Unrealized gains (losses) on available-for-sale securities	528,000	839,000	-638,000
Reclassification adjustments for losses on available-for-sale securities	-1,641,000	18,000	'
Total other comprehensive income	-2,083,000	1,288,000	2,255,000
Tax	'	'	'
Translation gains	-18,000	-151,000	-1,010,000
Reclassification adjustments for gains on sale of WLCSP	358,000	'	'
Unrealized gains (losses) on available-for-sale securities	-185,000	-148,000	299,000
Reclassification adjustments for losses on available-for-sale securities	354,000	-7,000	'
Total other comprehensive income	509,000	-306,000	-711,000
Net of Tax	'	'	'
Translation gains	35,000	280,000	1,883,000
Reclassification adjustments for gains on sale of WLCSP included, net of tax	-665,000	'	'
Unrealized gains (losses) on available-for-sale securities	343,000	691,000	-339,000
Reclassification adjustments for losses on available-for-sale securities	-1,287,000	11,000	'
Other comprehensive income (loss)	($1,574,000)	$982,000	$1,544,000

Comprehensive_Income_Details_2

Comprehensive Income (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Changes in accumulated other comprehensive income	'	'	'
Balance at the beginning of the period	$3,952	$2,970	'
Other Comprehensive Income (Loss), Before Tax	581	1,288	'
Amounts Reclassified out of Accumulated Other Comprehensive Income	-2,664	'	'
Related Tax Effects	509	-306	-711
Balance at the end of the period	2,378	3,952	2,970
Accumulated translation gains	'	'	'
Changes in accumulated other comprehensive income	'	'	'
Balance at the beginning of the period	3,036	2,756	'
Other Comprehensive Income (Loss), Before Tax	53	431	'
Amounts Reclassified out of Accumulated Other Comprehensive Income	-1,023	'	'
Related Tax Effects	340	-151	'
Balance at the end of the period	2,406	3,036	'
Accumulated unrealized gains (losses) on available-for-sale securities, net	'	'	'
Changes in accumulated other comprehensive income	'	'	'
Balance at the beginning of the period	916	214	'
Other Comprehensive Income (Loss), Before Tax	528	857	'
Amounts Reclassified out of Accumulated Other Comprehensive Income	-1,641	'	'
Related Tax Effects	169	-155	'
Balance at the end of the period	($28)	$916	'

Comprehensive_Income_Details_3

Comprehensive Income (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Amounts reclassified out of accumulated other comprehensive income	'	'	'
Other income (expense), net	($25,996)	($356)	$1,050
Amounts Reclassified out of Accumulated Other Comprehensive Income	'	'	'
Amounts reclassified out of accumulated other comprehensive income	'	'	'
Total amounts reclassified out of Accumulated Other Comprehensive Income	-2,664	'	'
Accumulated translation gains | Amounts Reclassified out of Accumulated Other Comprehensive Income	'	'	'
Amounts reclassified out of accumulated other comprehensive income	'	'	'
Other income (expense), net	-1,023	'	'
Accumulated unrealized gains (losses) on available-for-sale securities, net | Amounts Reclassified out of Accumulated Other Comprehensive Income	'	'	'
Amounts reclassified out of accumulated other comprehensive income	'	'	'
Other income (expense), net	($1,641)	'	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Jan. 31, 2014

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2014

Apr. 30, 2013

In Thousands, except Per Share data, unless otherwise specified

WLCSP

WLCSP

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Recurring Basis

Total

Total

Total

Total

Total

Total

Total

Total

Total

Level 1

Level 1

Level 1

Level 1

Level 1

Level 2

Level 2

Level 2

Level 2

Level 2

Level 2

Money market funds

Money market funds

U.S. government debt securities and municipal bonds

U.S. government debt securities and municipal bonds

Corporate debt securities/commercial paper

Corporate debt securities/commercial paper

Equity investment

Money market funds

Money market funds

Equity investment

U.S. government debt securities and municipal bonds

U.S. government debt securities and municipal bonds

Corporate debt securities/commercial paper

Corporate debt securities/commercial paper

Tong Hsing

Tong Hsing

Financial assets and liabilities measured at fair value on a recurring basis

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash equivalents

'

'

'

'

$102,812

$44,409

'

'

'

'

'

'

'

$57,207

$44,409

'

'

'

$45,605

'

'

'

'

'

Short-term investments

'

'

'

'

152,993

22,164

'

'

'

'

'

'

'

'

'

'

'

'

152,993

22,164

'

'

'

'

Long-term investments

'

'

'

'

'

5,313

'

'

'

'

'

'

'

'

5,313

'

'

'

'

'

'

'

'

'

Total assets

'

'

'

'

255,805

71,886

57,207

44,409

17,834

1,707

180,764

20,457

'

57,207

49,722

57,207

44,409

'

198,598

22,164

17,834

1,707

180,764

20,457

Interest rate swaps

-2,980

-4,184

'

'

-2,980

-4,184

'

'

'

'

'

'

'

'

'

'

'

'

-2,980

-4,184

'

'

'

'

Total liabilities

'

'

'

'

-2,980

-4,184

'

'

'

'

'

'

'

'

'

'

'

'

-2,980

-4,184

'

'

'

'

Closing price of stock (in dollars per share)

'

'

$5.50

$3.14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of equity method investment

'

'

$166,500

'

'

'

'

'

'

'

'

'

$5,313

'

'

'

'

$5,313

'

'

'

'

'

'

Common_Stock_and_Treasury_Stoc1

Common Stock and Treasury Stock (Details)	Apr. 30, 2014	Apr. 30, 2013
Common Stock and Treasury Stock	'	'
Number of shares of common stock authorized	100,000,000	100,000,000
Number of shares of common stock outstanding	56,081,586	53,975,195
Number of shares of treasury stock held by the entity	20,599,187	20,599,187

Common_Stock_and_Treasury_Stoc2

Common Stock and Treasury Stock (Details 2) (USD $)	Apr. 30, 2014	Apr. 30, 2013	Dec. 31, 2011	Nov. 30, 2011	Apr. 30, 2014	Apr. 30, 2014
			2011 new stock repurchase program	2011 new stock repurchase program	Equity incentive plans	Employee stock purchase plan
Common Stock and Treasury Stock	'	'	'	'	'	'
Common stock, shares reserved for issuance	'	'	'	'	13,655,166	2,543,504
Stock repurchase programs	'	'	'	'	'	'
Amount approved for repurchase of common stock	'	'	'	$100,000,000	'	'
Purchase of stock for treasury (in shares)	'	'	8,058,187	'	'	'
Aggregate cost of common stock repurchased	$278,683,000	$278,683,000	$100,000,000	'	'	'

Employee_Stock_Purchase_Equity2

Employee Stock Purchase, Equity Incentive and Stock Option Plans (Details)

12 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

12 Months Ended

Apr. 30, 2012

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2011

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Apr. 30, 2011

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Apr. 30, 2011

Feb. 29, 2000

Feb. 29, 2000

Apr. 30, 2014

Feb. 29, 2000

Feb. 29, 2000

Feb. 29, 2000

Feb. 29, 2000

Feb. 29, 2000

Feb. 29, 2000

Mar. 31, 2000

Mar. 31, 2000

Apr. 30, 2014

Mar. 31, 2000

Mar. 31, 2000

Sep. 30, 2013

Sep. 30, 2011

Apr. 30, 2014

Sep. 30, 2007

Sep. 30, 2007

Apr. 30, 2014

Sep. 30, 2007

Sep. 30, 2007

Apr. 30, 2014

Sep. 30, 2009

Apr. 30, 2014

Sep. 30, 2013

Stock options

Stock options

Stock options

Stock options

Restricted stock units

Restricted stock units

Restricted stock units

Restricted stock units

2000 Stock Plan

2000 Stock Plan

2000 Stock Plan

2000 Stock Plan

2000 Stock Plan

2000 Stock Plan

2000 Stock Plan

2000 Stock Plan

2000 Stock Plan

2000 Director Option Plan

2000 Director Option Plan

2000 Director Option Plan

2000 Director Option Plan

2000 Director Option Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2007 Equity Incentive Plan

2009 Purchase Plan

2009 Purchase Plan

2009 Purchase Plan

Stock options

Stock options

Stock options

Stock options

Stock options available for employees

Stock options available for employees

Nonstatutory stock options available for nonemployees

Nonstatutory stock options available for nonemployees

Stock options

Stock options

Nonstatutory stock options available for nonemployees

Nonstatutory stock options available for nonemployees

Stock options

Stock options

Stock option and stock appreciation right awards

Restricted stock units

Restricted stock units

item

Any person who owned more than 10% of the voting power of all classes of stock

Maximum

Minimum

Minimum

Minimum

Minimum

Nonemployee director

Minimum

Minimum

Any person who owned more than 10% of the voting power of all classes of stock

Any person who owned more than 10% of the voting power of all classes of stock

Nonemployee director

Employee Stock Purchase, Equity Incentive and Stock Option Plans

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares Authorized

'

18,100,000

'

'

'

'

'

'

'

'

'

'

6,000,000

'

'

'

'

'

'

'

'

500,000

'

'

'

'

'

'

18,100,000

6,000,000

'

'

'

'

'

2,500,000

'

2,500,000

Shares Available for Grant

7,488,000

6,921,000

4,759,000

2,717,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,921,000

'

'

'

'

'

'

'

'

'

Options Outstanding (in shares)

'

4,003,000

'

'

4,003,000

3,994,000

3,570,000

3,936,000

'

'

'

'

'

'

1,358,000

'

'

'

'

'

'

'

'

88,000

'

'

'

'

'

'

'

2,557,000

'

'

'

'

'

'

Restricted Stock Units Outstanding (in shares)

'

'

'

'

'

'

'

'

2,732,000

2,454,000

2,053,000

2,005,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,732,000

'

'

'

Grant date fair value (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

110.00%

85.00%

110.00%

'

100.00%

'

'

'

'

'

'

'

'

'

100.00%

'

'

85.00%

'

'

Expiration period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'7 years

'

'

'

'

'

'

'

Vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'3 years

'

'

'

'

Number of additional shares authorized

7,200,000

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

4,900,000

7,200,000

'

'

'

'

'

'

'

'

'

'

Annual increase in number of authorized shares under the first condition

'

'

'

'

'

'

'

'

'

'

'

'

3,000,000

'

'

'

'

'

'

'

'

150,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Annual increase in the number of shares reserved as a percent of the outstanding shares of the common stock on the last day of the prior fiscal year

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

'

'

'

'

'

'

'

'

0.25%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercisable period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Initial grant to purchase shares of common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

40,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Subsequent grants to purchase shares of common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Period served on the board of directors to be eligible for subsequent grants

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 months

'

'

'

'

'

'

'

'

'

'

'

'

Expiration period due to termination of optionee

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expiration period due to death or disability

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'12 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Initial share grants, exercisable rate on the first anniversary of the grant date (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.25

'

'

'

'

'

'

'

'

'

'

'

'

'

Initial share grants, exercisable rate per quarter thereafter (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.0625

'

'

'

'

'

'

'

'

'

'

'

'

'

Subsequent share grants, exercisable rate per quarter

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.0625

'

'

'

'

'

'

'

'

'

'

'

'

'

Offering period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'24 months

'

'

Number of purchase periods in each offering period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4

'

'

Purchase period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 months

'

'

Shares purchased

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,456,496

'

Employee_Stock_Purchase_Equity3

Employee Stock Purchase, Equity Incentive and Stock Option Plans (Details 2) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Shares Available For Grant	'	'	'
Balance at the beginning of the period (in shares)	4,759,000	7,488,000	2,717,000
2007 Plan amendment (in shares)	4,900,000	'	'
2007 Plan share increased (in shares)	'	'	7,200,000
Stock options granted (in shares)	-692,000	-644,000	-600,000
Stock options expired or forfeited (in shares)	171,000	2,000	28,000
Restricted stock units granted (in shares)	-2,627,000	-2,446,000	-2,088,000
Restricted stock units expired or forfeited (in shares)	410,000	359,000	231,000
Balance at the end of the period (in shares)	6,921,000	4,759,000	7,488,000
Options Outstanding, Number of Shares	'	'	'
Stock options granted (in shares)	692,000	644,000	600,000
Stock options expired or forfeited (in shares)	-171,000	-2,000	-28,000
Balance at the end of the period (in shares)	4,003,000	'	'
Restricted Stock Units Outstanding, Number of Shares	'	'	'
Restricted stock units granted (in shares)	2,627,000	2,446,000	2,088,000
Restricted stock units expired or forfeited (in shares)	-410,000	-359,000	-231,000
Stock options	'	'	'
Shares Available For Grant	'	'	'
Stock options granted (in shares)	-692,000	-644,000	-600,000
Stock options expired or forfeited (in shares)	218,000	83,000	81,000
Options Outstanding, Number of Shares	'	'	'
Balance at the beginning of the period (in shares)	3,994,000	3,570,000	3,936,000
Stock options granted (in shares)	692,000	644,000	600,000
Stock options exercised (in shares)	-465,000	-137,000	-885,000
Stock options expired or forfeited (in shares)	-218,000	-83,000	-81,000
Balance at the end of the period (in shares)	4,003,000	3,994,000	3,570,000
Exercisable at the end of the period (in shares)	2,806,000	'	'
Vested and expected to vest at the end of the period (in shares)	3,894,000	'	'
Options Outstanding, Weighted Average Exercise Price Per Share	'	'	'
Balance at the beginning of the period (in dollars per share)	18.93	19.53	16.31
Stock options granted (in dollars per share)	18.47	13.53	34.65
Stock options exercised (in dollars per share)	14.66	7.95	15.41
Stock options expired or forfeited (in dollars per share)	24.66	20.8	20.42
Balance at the end of the period (in dollars per share)	19.04	18.93	19.53
Exercisable at the end of the period (in dollars per share)	18.94	'	'
Vested and expected to vest at the end of the period (in dollars per share)	19.06	'	'
Restricted stock units	'	'	'
Shares Available For Grant	'	'	'
Restricted stock units granted (in shares)	-1,642,000	-1,528,000	-1,305,000
Restricted stock units expired or forfeited (in shares)	254,000	224,000	141,000
Restricted Stock Units Outstanding, Number of Shares	'	'	'
Balance at the beginning of the period (in shares)	2,454,000	2,053,000	2,005,000
Restricted stock units granted (in shares)	1,642,000	1,528,000	1,305,000
Restricted stock units vested (in shares)	-1,110,000	-903,000	-1,116,000
Restricted stock units expired or forfeited (in shares)	-254,000	-224,000	-141,000
Balance at the end of the period (in shares)	2,732,000	2,454,000	2,053,000
Vested and expected to vest at the end of the period (in shares)	2,430,000	'	'
Restricted Stock Units Outstanding, Weighted Average Grant Date Fair Market Value Per Share	'	'	'
Balance at the beginning of the period (in dollars per share)	20.3	27.24	16.81
Restricted stock units granted (in dollars per share)	18.36	13.39	32.27
Restricted stock units vested (in dollars per share)	22.02	24.39	14.84
Restricted stock units expired or forfeited (in dollars per share)	18.82	20.26	23.71
Balance at the end of the period (in dollars per share)	18.57	20.3	27.24
Vested and expected to vest at the end of the period (in dollars per share)	18.57	'	'
Restricted stock units granted after September 2009	'	'	'
Other general disclosures	'	'	'
Number of shares reserved for every one share subject to awards granted for less than fair market value on the date of grant	1.6	'	'
Number of shares to be credited back to the reserve when a share is returned to the plan	1.6	'	'
Restricted stock units granted before September 2009	'	'	'
Other general disclosures	'	'	'
Number of shares reserved for every one share subject to awards granted for less than fair market value on the date of grant	2	'	'
Number of shares to be credited back to the reserve when a share is returned to the plan	2	'	'

Employee_Stock_Purchase_Equity4

Employee Stock Purchase, Equity Incentive and Stock Option Plans (Details 3) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Apr. 30, 2014
Other disclosures	'
Closing stock price (in dollars per share)	$19.53
Total number of in-the-money stock options exercisable (in shares)	1,933,798
Stock options	'
Options outstanding	'
Options Outstanding (in shares)	4,003,000
Weighted Average Remaining Contractual Life	'3 years 11 months 12 days
Weighted Average Exercise Price (in dollars per share)	$19.04
Aggregate Intrinsic Value	$11,589
Options Vested and Exercisable (in shares)	2,806,000
Weighted Average Remaining Contractual Life	'3 years 3 months 4 days
Weighted Average Exercise Price (in dollars per share)	$18.94
Aggregate Intrinsic Value	$8,792
$5.82 - $13.34 | Stock options	'
Options outstanding	'
Exercise price, lower range limit (in dollars per share)	$5.82
Exercise price, upper range limit (in dollars per share)	$13.34
Options Outstanding (in shares)	875,000
Weighted Average Remaining Contractual Life	'5 years 4 days
Weighted Average Exercise Price (in dollars per share)	$12.34
Options Vested and Exercisable (in shares)	570,000
Weighted Average Exercise Price (in dollars per share)	$11.80
$13.61 - $16.69 | Stock options	'
Options outstanding	'
Exercise price, lower range limit (in dollars per share)	$13.61
Exercise price, upper range limit (in dollars per share)	$16.69
Options Outstanding (in shares)	938,000
Weighted Average Remaining Contractual Life	'2 years 10 months 28 days
Weighted Average Exercise Price (in dollars per share)	$15.51
Options Vested and Exercisable (in shares)	889,000
Weighted Average Exercise Price (in dollars per share)	$15.53
$16.85 - $18.47 | Stock options	'
Options outstanding	'
Exercise price, lower range limit (in dollars per share)	$16.85
Exercise price, upper range limit (in dollars per share)	$18.47
Options Outstanding (in shares)	964,000
Weighted Average Remaining Contractual Life	'4 years 10 months 24 days
Weighted Average Exercise Price (in dollars per share)	$18.04
Options Vested and Exercisable (in shares)	305,000
Weighted Average Exercise Price (in dollars per share)	$17.11
$18.77 - $25.56 | Stock options	'
Options outstanding	'
Exercise price, lower range limit (in dollars per share)	$18.77
Exercise price, upper range limit (in dollars per share)	$25.56
Options Outstanding (in shares)	718,000
Weighted Average Remaining Contractual Life	'2 years 6 months 25 days
Weighted Average Exercise Price (in dollars per share)	$21.98
Options Vested and Exercisable (in shares)	693,000
Weighted Average Exercise Price (in dollars per share)	$21.98
$34.80 - $34.80 | Stock options	'
Options outstanding	'
Exercise price, lower range limit (in dollars per share)	$34.80
Exercise price, upper range limit (in dollars per share)	$34.80
Options Outstanding (in shares)	508,000
Weighted Average Remaining Contractual Life	'4 years 2 months 1 day
Weighted Average Exercise Price (in dollars per share)	$34.80
Options Vested and Exercisable (in shares)	349,000
Weighted Average Exercise Price (in dollars per share)	$34.80

Employee_Stock_Purchase_Equity5

Employee Stock Purchase, Equity Incentive and Stock Option Plans (Details 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Stock options	'	'
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'	'
Total intrinsic value of options exercised	$1,784	$1,015
Total cash received from employees as a result of employee stock option exercises	6,825	1,085
Restricted stock units	'	'
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'	'
Total intrinsic value of restricted stock units vested	$20,330	$12,096

Employee_Stock_Purchase_Equity6

Employee Stock Purchase, Equity Incentive and Stock Option Plans (Details 5) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Stock options	'	'
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'	'
Unrecognized compensation expense, net of forfeitures	$8,403	$8,444
Weighted average period	'2 years 6 months	'2 years 6 months
Restricted stock units	'	'
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'	'
Unrecognized compensation expense, net of forfeitures	28,749	28,818
Weighted average period	'1 year 8 months 12 days	'1 year 8 months 12 days
2009 Employee Stock Purchase Plan	'	'
Employee Stock Purchase, Equity Incentive and Stock Option Plans	'	'
Unrecognized compensation expense, net of forfeitures	$3,396	$1,063
Weighted average period	'1 year 1 month 6 days	'7 months 6 days

Employee_Stock_Purchase_Equity7

Employee Stock Purchase, Equity Incentive and Stock Option Plans (Details 6) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Stock options	'	'	'
Per share weighted average estimated grant date fair value for employee options granted using the Black-Scholes option pricing model	'	'	'
Per share weighted average estimated grant date fair value (in dollars per share)	$7.92	$6.36	$15.37
Assumptions used to estimate fair value calculations for stock options granted	'	'	'
Risk-free interest rate (as a percent)	1.00%	0.60%	1.30%
Expected term of options	'4 years 7 months 2 days	'4 years 3 months 18 days	'4 years 2 months 12 days
Expected volatility (as a percent)	51.00%	60.00%	55.00%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%
The minimum life for Company traded options used in the determination of implied volatility for option pricing models	'6 months	'	'
Employee Stock Purchase Plan	'	'	'
Assumptions used to estimate fair value calculations for stock options granted	'	'	'
Risk-free interest rate (as a percent)	0.10%	0.10%	0.10%
Expected term of options	'6 months	'6 months	'6 months
Expected volatility (as a percent)	46.00%	63.00%	53.00%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%
Per share weighted average estimated fair value of rights issued using the Black-Scholes option pricing model	'	'	'
Per share weighted average estimated fair value of rights issued (in dollars per share)	$5.83	$6.06	$5.54

Risks_and_Uncertainties_Detail

Risks and Uncertainties (Details)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Revenue | Customer concentration | Customer A	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	13.80%	10.70%	'
Revenue | Customer concentration | Customer A | Maximum percentage	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	'	'	10.00%
Revenue | Customer concentration | Customer B	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	12.50%	10.30%	'
Revenue | Customer concentration | Customer B | Maximum percentage	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	'	'	10.00%
Revenue | Customer concentration | Customer C	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	11.00%	11.70%	13.50%
Revenue | Customer concentration | Customer D	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	'	18.00%	15.20%
Revenue | Customer concentration | Customer D | Maximum percentage	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	10.00%	'	'
Accounts receivable, net | Credit concentration | Customer A	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	17.00%	'	'
Accounts receivable, net | Credit concentration | Customer A | Maximum percentage	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	'	10.00%	'
Accounts receivable, net | Credit concentration | Customer B	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	12.70%	15.10%	'
Accounts receivable, net | Credit concentration | Customer C	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	10.40%	'	'
Accounts receivable, net | Credit concentration | Customer C | Maximum percentage	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	'	10.00%	'
Accounts receivable, net | Credit concentration | Customer D	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	'	15.30%	'
Accounts receivable, net | Credit concentration | Customer D | Maximum percentage	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	10.00%	'	'
Accounts receivable, net | Credit concentration | Customer E	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	'	11.10%	'
Accounts receivable, net | Credit concentration | Customer E | Maximum percentage	'	'	'
Risks and Uncertainties	'	'	'
Percentage of concentration risk	10.00%	'	'

Segment_and_Geographic_Informa2

Segment and Geographic Information (Details) (Sales)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Geographical segment information	'	'	'
Revenues by customer segment (as a percent)	100.00%	100.00%	100.00%
OEMs and VARs	'	'	'
Geographical segment information	'	'	'
Revenues by customer segment (as a percent)	81.20%	81.20%	78.10%
Distributors	'	'	'
Geographical segment information	'	'	'
Revenues by customer segment (as a percent)	18.80%	18.80%	21.90%

Segment_and_Geographic_Informa3

Segment and Geographic Information (Details 2) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Revenues	$330,969	$352,023	$397,249	$373,688	$336,215	$423,513	$390,137	$258,064	$1,453,929	$1,407,929	$897,730
Long-lived assets	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Long-lived assets	340,202	'	'	'	328,555	'	'	'	340,202	328,555	'
China | Sales	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	1,122,802	955,378	520,452
China | Long-lived assets	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Long-lived assets	162,207	'	'	'	139,482	'	'	'	162,207	139,482	'
Taiwan | Sales	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	23,748	27,120	18,253
Taiwan | Long-lived assets	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Long-lived assets	126,820	'	'	'	137,359	'	'	'	126,820	137,359	'
South Korea | Sales	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	158,693	275,105	147,390
Japan | Sales	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	89,311	57,604	46,108
United States | Sales	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	4,781	3,997	61,766
United States | Long-lived assets	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Long-lived assets	50,552	'	'	'	50,903	'	'	'	50,552	50,903	'
All other | Sales	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	54,594	88,725	103,761
All other | Long-lived assets	'	'	'	'	'	'	'	'	'	'	'
Geographical segment information	'	'	'	'	'	'	'	'	'	'	'
Long-lived assets	$623	'	'	'	$811	'	'	'	$623	$811	'

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended					12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012	Jan. 31, 2014	Jul. 31, 2013	Apr. 30, 2014
				OmniVision Technologies (Wuhan) Co. Ltd. ("OV-Wuhan")	OmniVision Technologies (Wuhan) Co. Ltd. ("OV-Wuhan")	OmniVision Technologies (Wuhan) Co. Ltd. ("OV-Wuhan")
						Research and development efforts
Commitments	'	'	'	'	'	'
Aggregate payment commitment	'	'	'	$3,500,000	$1,000,000	'
Amount contributed under agreement	'	'	'	'	'	3,500,000
Future minimum lease commitments under operating leases	'	'	'	'	'	'
2015	6,012,000	'	'	'	'	'
2016	5,378,000	'	'	'	'	'
2017	2,078,000	'	'	'	'	'
2018	816,000	'	'	'	'	'
2019	796,000	'	'	'	'	'
Thereafter	1,320,000	'	'	'	'	'
Total	16,400,000	'	'	'	'	'
Rental expenses under all operating leases	'	'	'	'	'	'
Rental expenses under operating leases	$9,775,000	$11,491,000	$9,293,000	'	'	'

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 2)	0 Months Ended
	Aug. 09, 2012	Nov. 22, 2011	Dec. 06, 2010	Oct. 26, 2011	10-May-12	Mar. 21, 2012	Nov. 15, 2011
	Patent infringement	Patent infringement	Patent infringement	Violation of the federal securities laws	Shareholder derivative complaint	Shareholder derivative complaint	Shareholder derivative complaint
	patent	patent	patent	director	complaint	complaint	complaint
				executive
Litigation	'	'	'	'	'	'	'
Number of patents allegedly infringed	3	5	6	'	'	'	'
Number of executives against whom case has been filed	'	'	'	3	'	'	'
Number of Directors against whom case has been filed	'	'	'	1	'	'	'
Number of shareholder derivative complaints	'	'	'	'	5	4	3

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
VisEra Technologies Company, Ltd. ("VisEra")	'	'	'
Related Party Transactions	'	'	'
Purchases of services	$119,919	$166,100	$121,008
Rent and other services	3	3,664	1,972
Balance payable at year end, net	19,160	28,024	17,329
WLCSP	'	'	'
Related Party Transactions	'	'	'
Purchases of services	2,097	'	'
Balance payable at year end, net	$1,156	'	'

Supplementary_Data_Unaudited_D

Supplementary Data (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Supplementary Data (Unaudited)	'	'	'	'	'	'	'	'	'	'	'
Revenues	$330,969	$352,023	$397,249	$373,688	$336,215	$423,513	$390,137	$258,064	$1,453,929	$1,407,929	$897,730
Cost of revenues	264,406	282,891	322,383	308,527	277,486	352,027	325,453	208,849	1,178,207	1,163,815	649,719
Gross profit	66,563	69,132	74,866	65,161	58,729	71,486	64,684	49,215	275,722	244,114	248,011
Net income	$15,073	$30,560	$26,303	$23,061	$8,922	$21,308	$10,345	$2,327	$94,997	$42,902	$65,849
Net income per share:	'	'	'	'	'	'	'	'	'	'	'
Basic (in dollars per share)	$0.27	$0.55	$0.47	$0.42	$0.17	$0.40	$0.19	$0.04	$1.71	$0.80	$1.16
Diluted (in dollars per share)	$0.26	$0.54	$0.47	$0.42	$0.17	$0.40	$0.19	$0.04	$1.70	$0.80	$1.13
Shares used in computing net income per share:	'	'	'	'	'	'	'	'	'	'	'
Basic (in shares)	56,042	55,913	55,584	54,611	53,943	53,830	53,514	52,830	55,537	53,529	56,666
Diluted (in shares)	56,882	56,186	55,732	55,344	54,061	53,930	53,675	52,865	56,043	53,671	58,233

SCHEDULE_II_VALUATION_AND_QUAL1

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Allowance for doubtful accounts	'	'	'
VALUATION AND QUALIFYING ACCOUNTS	'	'	'
Balance at Beginning of Year	$945	$555	$1,834
Additions and Charges to Expenses	53	390	-174
Write-offs and Deductions	'	'	1,105
Balance at End of Year	998	945	555
Deferred tax valuation allowance	'	'	'
VALUATION AND QUALIFYING ACCOUNTS	'	'	'
Balance at Beginning of Year	12,116	10,419	8,058
Additions and Charges to Expenses	5,210	1,697	2,361
Balance at End of Year	17,326	12,116	10,419
Allowance for sales returns	'	'	'
VALUATION AND QUALIFYING ACCOUNTS	'	'	'
Balance at Beginning of Year	5,371	2,489	2,305
Additions and Charges to Expenses	'	10,327	3,283
Write-offs and Deductions	2,265	7,445	3,099
Balance at End of Year	$3,106	$5,371	$2,489