Electro Scientific Industries (ESIO) 10-K 8 Jun 18 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2018	Jun. 04, 2018	Sep. 30, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Entity Registrant Name	ELECTRO SCIENTIFIC INDUSTRIES INC
Entity Central Index Key	726,514
Current Fiscal Year End Date	--03-28
Entity Well-know Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		34,104,459
Entity Public Float			$ 402,636,055

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Apr. 01, 2017
Current assets:
Cash and Cash Equivalents, at Carrying Value	$ 76,792	$ 56,642
Short-term investments	47,121	5,743
Accounts Receivable, Net, Current	63,044	40,494
Inventories	87,686	58,942
Shipped systems pending acceptance	4,734	5,713
Other current assets	5,493	6,180
Total current assets	284,870	173,714
Non-current assets:
Property, plant and equipment, net	22,025	21,619
Non-current deferred income taxes, net	43,518	890
Goodwill	2,626	3,027
Acquired intangible assets, net	5,169	6,564
Other assets	14,780	18,931
Total assets	372,988	224,745
Current liabilities:
Accounts payable	37,354	21,213
Accrued liabilities	34,533	22,186
Deferred revenue	9,818	14,712
Total current liabilities	81,705	58,111
Long-term Debt, Excluding Current Maturities	12,766	13,489
Non-current liabilities:
Non-current income taxes payable	1,901	1,036
Liabilities, Other than Long-term Debt, Noncurrent	10,258	7,578
Liabilities	106,630	80,214
Commitments and Contingencies
Shareholders' equity:
Preferred stock, without par value	0	0
Common stock, without par value	210,995	207,152
Retained earnings	54,816	(61,407)
Accumulated other comprehensive income	547	(1,214)
Total shareholders' equity	266,358	144,531
Total liabilities and shareholders' equity	$ 372,988	$ 224,745

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Apr. 01, 2017
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 832	$ 603
Preferred Stock, No Par Value	$ 0	$ 0
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, Shares Issued	0	0
Common Stock, No Par Value	$ 0	$ 0
Common Stock, Shares Authorized	100,000,000	100,000,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 83,159	$ 112,075
Finite-Lived Intangible Assets, Accumulated Amortization	$ 22,766	$ 21,994
Common Stock, Shares, Issued	34,387,000	33,260,000
Common Stock, Shares, Outstanding	34,387,000	33,260,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Revenue, Net	$ 367,884	$ 161,023	$ 184,391
Sales Revenue, Goods, Net	325,349	125,098	142,957
Sales Revenue, Services, Net	42,535	35,925	41,434
Cost of sales	207,054	99,557	111,688
Gross Profit	160,830	61,466	72,703
Cost of Goods Sold	185,354	81,350	89,169
Cost of Services	21,700	18,207	22,519
Operating expenses:
Selling, service and administration	46,624	52,698	49,753
Research, development and engineering	34,411	31,719	32,400
Restructuring costs	3,935	6,935	2,824
Business Combination, Integration Related Costs	0	366	194
Goodwill, Impairment Loss	0	7,445	0
Net operating expenses	84,970	99,163	85,171
Operating (loss) income	75,860	(37,697)	(12,468)
Non-operating (expense) income:
Interest and other (expense) income, net	93	265	195
Total non-operating (expense) income	93	265	195
Income (loss) before income taxes	75,953	(37,432)	(12,273)
Provision for (benefit from) income taxes	(40,270)	(23)	(16)
Net (loss) income	$ 116,223	$ (37,409)	$ (12,257)
Net (loss) income per share - basic	$ 3.42	$ (1.15)	$ (0.39)
Net (loss) income per share - diluted	$ 3.27	$ (1.15)	$ (0.39)
Weighted average number of shares - basic	33,967	32,551	31,411
Weighted average number of shares - diluted	35,571	32,551	31,411

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) Statement - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Net (loss) income	$ 75,088	$ 33,973	$ 4,260	$ 2,902	$ (17,923)	$ (9,693)	$ (9,675)	$ (118)	$ 116,223	$ (37,409)	$ (12,257)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax									1,832	(348)	(922)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax									(61)	135	(4)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax									(10)	(6)	3
Other Comprehensive Income (Loss), Net of Tax									1,761	(219)	(923)
Comprehensive (loss) income									$ 117,984	$ (37,628)	$ (13,180)

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	$ 339	$ 0	$ 0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	58	(74)	(21)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	$ 25	$ 0	$ 1

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of year at Mar. 28, 2015	$ 177,321	$ 189,134	$ (11,741)	$ (72)
Balance at beginning of year (shares) at Mar. 28, 2015		30,704
Stock plans:
Employee stock plans (shares)		909
Employee stock plans	5,827	$ 5,827
Stock Repurchased During Period, Value	0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value	(63)
Comprehensive income (loss):
Net (loss) income	(12,257)		(12,257)
Other Comprehensive Income (Loss), Net of Tax	(923)			(923)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	3
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(922)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	(4)
Comprehensive (loss) income	(13,180)
Balance at end of year at Apr. 02, 2016	170,031	$ 195,024	(23,998)	(995)
Balance at end of year (shares) at Apr. 02, 2016		31,613
Stock plans:
Employee stock plans (shares)		1,647
Employee stock plans	7,652	$ 7,652
Stock Repurchased During Period, Value	0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value	(4,476)
Comprehensive income (loss):
Net (loss) income	(37,409)
Other Comprehensive Income (Loss), Net of Tax	(219)			(219)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	(6)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(348)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	135
Comprehensive (loss) income	(37,628)			(219)
Balance at end of year at Apr. 01, 2017	144,531	$ 207,152	(61,407)	(1,214)
Balance at end of year (shares) at Apr. 01, 2017		33,260
Stock plans:
Employee stock plans (shares)		1,127
Employee stock plans	4,104	$ 4,104
Stock Repurchased During Period, Value	0
Business Combination, Step Acquisition, Equity Interest Clawback	(261)
Comprehensive income (loss):
Net (loss) income	116,223
Other Comprehensive Income (Loss), Net of Tax	1,761			1,761
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	(10)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	1,832
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	(61)
Comprehensive (loss) income	117,984			1,761
Balance at end of year at Mar. 31, 2018	$ 266,358	$ 210,995	$ 54,816	$ 547
Balance at end of year (shares) at Mar. 31, 2018		34,387

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Mar. 31, 2018USD ($)	Apr. 01, 2017USD ($)	Apr. 02, 2016USD ($)
Restructuring Costs and Asset Impairment Charges	$ 5,610	$ 0	$ 0
Proceeds from Divestiture of Businesses	2,999	0	0
Cash, Cash Equivalents, and Restricted Cash; At Carrying Value	77,885	57,732	42,413
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	116,223	(37,409)	(12,257)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	7,817	7,566	7,343
Amortization	1,373	1,530	1,376
Share-based compensation expense	4,802	7,095	5,103
Provision for (recovery of) doubtful accounts	731		329
Allowance for Doubtful Accounts Receivable, Recoveries		(429)
Gain on sale of property and equipment, net	197	1,323	862
Business Combination, Bargain Purchase, Gain Recognized, Amount	917	0	0
Impairment of Intangible Assets, Finite-lived	0	2,349	0
Impairment of Inventory due to Restructuring	8,200	1,700	1,400
Inventory Write-down	8,248	2,440	0
Goodwill, Impairment Loss	0	7,445	0
Decrease (increase) in deferred income taxes	(42,251)	(254)	(877)
Changes in operating accounts, net of acquisitions:
Decrease (increase) in trade receivables, net	(22,415)	2,571	2,984
Decrease (increase) in inventories	(37,241)	(6,252)	(7,303)
Decrease (increase) in shipped systems pending acceptance	979	(4,532)	1,631
Decrease (increase) in other current assets	1,249	(755)	1,154
Increase (decrease) in accounts payable and accrued liabilities	27,917	8,141	9,048
Increase (decrease) in deferred revenue	(4,894)	8,338	(4,691)
Net cash (usedin) provided by operating activities	67,428	(833)	4,702
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of investments	(73,044)	(464,893)	(380,841)
Proceeds from sales and maturities of investments	32,666	473,842	369,700
Purchase of property, plant and equipment	(4,848)	(4,039)	(3,693)
Proceeds from sale of property, plant and equipment	37	7	232
Cash paid to acquire subsidiaries	0	2,010	0
Decrease (increase) in other assets	(5,163)	(293)	790
Net cash provided by (used in) investing activities	(47,353)	2,614	(13,812)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from Issuance of Common Stock	3,463	1,398	1,362
Proceeds from Issuance of Other Long-term Debt	0	13,683	0
Repayments of Long-term Debt	(434)	(77)	0
Payments Related to Tax Withholding for Share-based Compensation	(4,161)	(839)	(638)
Stock Repurchased During Period, Value	0	0	0
Net cash (used in) provided by financing activities	(1,132)	14,165	724
Effect of exchange rate changes on cash	1,210	(627)	(195)
CashAndCashEquivalentsAndRestrictedCashPeriodIncreaseDecrease	20,153	15,319	(8,581)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	56,642
CASH AND CASH EQUIVALENTS AT END OF PERIOD	76,792	56,642
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for interest	(652)	(121)	(57)
Cash paid for income taxes	(1,198)	(530)	(806)
Income tax refunds received	132	123	140
Property, Plant and Equipment, Gross, Period Increase (Decrease)	(1,039)	5,985	3,866
Property, Plant and Equipment, Additions	$ 1,899	$ 40	766
Retained Earnings [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income			$ (12,257)

The Company

The Company	12 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	Electro Scientific Industries, Inc. and its wholly-owned subsidiaries (ESI or the Company) is a leading supplier of innovative laser-based microfabrication solutions for industries reliant on microtechnologies. ESI enables its customers to commercialize technology using precision laser processes. Founded in 1944, ESI is headquartered in Portland, Oregon, with global operations and subsidiaries in Asia, Europe and North America.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	sis of Presentation The accompanying Consolidated Financial Statements include the accounts of Electro Scientific Industries, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated. The Company’s fiscal year consists of 52 or 53 week periods ending on the Saturday nearest March 31. Accordingly, the fiscal 2018 reporting period consisted of a 52 -week period ending on March 31, 2018 , the fiscal 2017 reporting period consisted of a 52 -week period ending on April 1, 2017 and the fiscal 2016 reporting period consisted of a 53 -week period ending on April 2, 2016 . All references to years or quarters relate to fiscal years or fiscal quarters unless otherwise noted. Estimates The preparation of Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of commitments and contingencies at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results may differ from those estimates. Management believes that the estimates used are reasonable. Estimates made by management include: revenue recognition; inventory valuation; valuation of investments; accrued restructuring costs; share-based compensation; income taxes, including the valuation of deferred tax assets; valuation of long-lived assets, including intangibles; goodwill and acquisition accounting. Risks and Uncertainties The Company uses financial instruments that potentially subject it to concentrations of credit risk. Such instruments include cash equivalents, available-for-sale marketable securities, trade receivables and financial instruments used in hedging activities. The Company primarily invests cash in money market funds, commercial paper, highly rated corporate bonds, certificates of deposit and readily marketable securities. Investments are placed with high credit quality financial institutions and the credit exposure from any one institution or instrument is minimized. See Note 4: Fair Value Measurements for further discussion on these investments. The Company sells a significant portion of its products to a small number of large printed circuit board (PCB), semiconductor and microelectronics manufacturers. The Company's top ten customers for 2018 , 2017 and 2016 accounted for approximately 59% , 47% and 51% of total net sales, respectively. In 2018 , two customers, Career Technology (Mfg.). Co. Ltd. and Top Unique Trading Co. LTD., accounted for approximately 17% and 13% of net sales, respectively. In 2017 , two customers, Sumitomo Corporation and Zhen Ding Technologies, accounted for approximately 12% and 11% of net sales, respectively. One customer, Apple Inc. and its affiliates, accounted for approximately 15% of net sales in 2016 . No other customer individually accounted for more than 10% of total net sales in 2018 , 2017 or 2016 . The Company uses qualified manufacturers to supply many components and sub-system modules of its products. The systems that the Company manufactures use high-performance computers, peripherals, lasers and other components from various suppliers. The Company obtains some of the components from a single source or a limited group of suppliers. An interruption in the supply of a particular component may have a temporary adverse impact on the Company’s operating results. The Company’s operations involve a number of other risks and uncertainties including but not limited to those relating to the cyclicality and seasonality of the microelectronics and semiconductor markets, the effect of general economic conditions, rapid changes in technology and international operations. Cash Equivalents and Investments All highly liquid investments with a maturity of 90 days or less at the date of purchase are considered to be cash equivalents. Short-term investments reflect marketable securities that have maturities of less than one year or are subject to immediate pre-payment or call provisions. These securities consist primarily of marketable debt securities and are classified as “available-for-sale securities” and recorded at fair market value. Unrealized gains and losses on investments are recorded as a component of accumulated other comprehensive income (loss). To determine whether any existing impairment is other-than-temporary and requires recognition of an impairment loss in the results of operations, the Company evaluates its marketable securities based on the nature of the investments and the Company’s intent and ability to hold the securities until the securities are no longer in an unrealized loss position. Restricted Cash Cash and cash equivalents that are restricted as to withdrawal or use under the terms of certain long-term contractual agreements are recorded in Other non-current assets on the Company's Consolidated Balance Sheets. The following table provides a reconciliation of cash, cash equivalents, and restricted cash as shown in the statement of cash flows: (In thousands) 2018 2017 Cash and cash equivalents $ 76,792 $ 56,642 Restricted cash included in other long-term assets 1,093 1,090 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 77,885 $ 57,732 Accounts Receivable and Allowance for Doubtful Accounts Trade receivables are stated at the amount the Company expects to collect and generally do not bear interest. Credit limits are established by reviewing the financial history and stability of each customer. Where appropriate, the Company obtains credit rating reports and financial statements of the customer to establish or modify credit limits. On certain foreign sales, letters of credit are obtained. The collectability of trade receivable balances is regularly evaluated based on a combination of factors such as customer reputation and credit-worthiness, past transaction history with the customer, current economic and industry trends, among other factors. If it is determined or expected that a customer will be unable to fully meet its financial obligation, such as in the case of a bankruptcy filing or other material events impacting its business, a specific allowance for bad debt is recorded to reduce the related receivable to the amount expected to be recovered. Accrued Restructuring Costs The Company has engaged, and may continue to engage, in restructuring actions, which require it to make estimates in certain areas including expenses for severance and other employee separation costs. Because the Company has a history of paying severance benefits, expenses associated with exit or disposal activities are recognized when probable and estimable. Should the actual amounts differ from the Company's estimates, the amount of the restructuring charges could be materially impacted. See Note 22: Restructuring and Cost Management Plans for further discussion. Inventories Inventories are principally valued at standard costs, which approximate the lower of cost or net realizable value on a first-in, first-out basis. Costs utilized for inventory valuation purposes include material, labor and manufacturing overhead. The Company regularly evaluates the carrying value of inventory based on a combination of factors including, but not limited to, the following: product maturity, forecasted sales or usage, historical usage rates, estimated service period, product end-of-life dates, estimated current and future market values, service inventory requirements and new product introductions. Purchasing requirements and alternative uses for the inventory are explored within these processes to mitigate inventory exposure. Inventory materials with quantities in excess of forecasted usage are reviewed quarterly for obsolescence. Obsolescence write-downs are typically caused by strategic decisions to exit or alter product lines, engineering change orders or product life cycle changes. If circumstances related to the Company's inventories change, its estimate of the value of inventory could materially change. Research and development product costs are generally expensed as incurred. Engineering materials that are expected to be sold to a customer for value are generally classified as raw materials inventory. Shipped Systems Pending Acceptance Shipped systems pending acceptance relate to systems that have been ordered and shipped to the customer, but where revenue has been deferred in accordance with the Company’s revenue recognition policy. Shipped systems pending acceptance are recognized as cost of sales once all criteria for revenue recognition have been met and revenue is recorded. Shipped systems pending acceptance are valued at standard costs, which approximate the lower of cost (first-in, first-out) or net realizable value. Costs utilized in the valuation of shipped systems pending acceptance include material, labor and manufacturing overhead and exclude costs of installation. Property, Plant and Equipment Property, plant and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line basis over the estimated useful lives of the assets. Expenditures for maintenance, repairs and minor improvements are expensed as incurred. Major improvements and additions are capitalized. When assets are sold or retired in the normal course of business, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss is included as a component of operating expenses. Long-Lived Assets Long-lived assets, principally property, plant and equipment and identifiable long-lived intangibles, are reviewed for impairment whenever events or circumstances indicate that the carrying amount of the assets may not be recoverable. The Company evaluates the recoverability of assets to be held and used by comparing the carrying amount of an asset or asset group to estimated future net undiscounted cash flows generated by the asset. If such assets are considered to be impaired, the impairment recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. The Company’s purchased patents are amortized over their estimated useful lives, generally nine to seventeen years. Other purchased intangible assets with finite useful lives are carried at cost less accumulated amortization. Amortization expense is recognized on a straight-line basis over the estimated useful lives of the intangible assets, which range from one to ten years. Acquisition Accounting The fair value of the consideration exchanged in an acquisition is allocated to tangible assets and identifiable intangible assets acquired and liabilities assumed at acquisition date fair value. Goodwill is measured as the excess of the consideration transferred over the net fair value of identifiable assets acquired and liabilities assumed. The accounting for an acquisition involves a considerable amount of judgment and estimation. Cost, income, market or a combination of approaches may be used to establish the fair value of consideration exchanged, assets acquired and liabilities assumed, depending on the nature of those items. The valuation approach is determined in accordance with generally accepted valuation methods or other generally accepted methods. Key areas of estimation and judgment may include the selection of valuation approaches, identification and selection of comparable companies or transactions, projections of future performance, cost of capital, market characteristics, cost structure, impacts of synergies, and estimates of terminal value, among other factors. While the Company uses best estimates and assumptions as part of the purchase price allocation process to estimate the value of assets acquired and liabilities assumed, estimates are inherently uncertain and subject to refinement. During the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed, with a corresponding offset to goodwill, to the extent that adjustments are identified to the preliminary purchase price allocation. Upon conclusion of the measurement period, or final determination of the value of the assets acquired and liabilities assumed, whichever comes first, any subsequent adjustments are recorded to results from operations. See Note 26: Business Acquisitions for further discussion of purchase accounting, valuation methodology and assumptions. Goodwill The Company tests goodwill for impairment annually or more frequently if an event occurs or circumstances would indicate that it is more likely than not the fair value of the reporting unit is less than the carrying value. The date of the annual test of goodwill is the first day of the fourth quarter. The carrying value of the reporting unit is determined based on an allocation of the Company's assets and liabilities to the reporting unit using reasonable assumptions. An impairment is recorded in the period identified in the amount by which the carrying value of reporting unit exceeds the fair value of the reporting unit, up to the amount of goodwill recorded. Other Assets Other assets include customer loans, consignment, demonstration (demo) and training equipment, long-term deposits, and non-current accounts receivable. Customer loans, consignment, demo and training equipment are recorded at the lower of standard costs or estimated market values. Fair Value of Financial Instruments The carrying amounts of financial instruments, including cash equivalents, accounts receivable, accounts payable, accrued liabilities and income taxes payable approximate fair value because of the nature of the underlying transactions and short-term maturities involved. Current and non-current marketable securities are recorded at fair value which is defined under FASB ASC Topic 820 “Fair Value Measurements and Disclosures” (ASC Topic 820). ASC Topic 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include the following: • Level 1 , defined as observable inputs such as quoted prices in active markets for identical assets or liabilities; • Level 2 , defined as inputs that are observable either directly or indirectly such as quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active and other inputs that can be corroborated by observable market data; and • Level 3 , defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. See Note 4: Fair Value Measurements for further discussion and disclosure of fair value on the Company's financial assets and investments. Derivative Financial Instruments The Company’s primary objective for holding derivative financial instruments is to manage currency risk. The Company’s accounting policies for these instruments are based on whether they meet the Company’s criteria for designation as hedging transactions, either as cash flow or fair value hedges. A hedge of the exposure to variability in the cash flows of an asset or a liability, or of a forecasted transaction, is referred to as a cash flow hedge. A hedge of the exposure to changes in fair value of an asset or a liability, or of an unrecognized firm commitment, is referred to as a fair value hedge. The criteria for designating a derivative as a hedge include the instrument’s effectiveness in risk reduction and, in most cases, a one-to-one matching of the derivative instrument to its underlying transaction. The Company enters into foreign currency exchange contracts as cashflow hedges to offset the earnings impact relating to the variability in exchange rates on certain short-term monetary assets and liabilities denominated in non-functional currencies. The Company does not designate these foreign currency contracts as hedges. The change in fair value of these derivative instruments not designated as hedging instruments is reported each period in other income (expense), net, in the Consolidated Statements of Operations. Revenue Recognition The Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or the services have been rendered, the sales price is fixed or determinable and collection of the related receivable is reasonably assured. Title and risk of loss generally pass to the customer at the time of delivery of the product to a common carrier. Revenue is recognized upon such delivery, provided that fulfillment of acceptance criteria can be demonstrated prior to shipment. Where the acceptance criteria cannot be demonstrated prior to shipment, as in the case of substantially new products, revenue is deferred until acceptance has been received. For multiple element arrangements, the relative fair value of any undelivered elements is deferred until the elements are delivered and acceptance criteria, if any, are met. Revenues are recorded net of taxes collected which are required to be submitted to government authorities. Installation services are not essential to the functionality of the delivered equipment and installation revenue is deferred as a separate deliverable until installation is complete. Neither accrued installation costs nor the fair value of installation service revenue deferred has been material. Revenues associated with sales to customers under local contracts in Japan are generally recognized upon title transfer, which occurs upon customer acceptance. Revenues related to spare parts and consumable sales are generally recognized upon shipment. Revenues related to maintenance and service contracts are generally recognized ratably over the duration of the contracts. Product Warranty The Company evaluates obligations related to product warranties quarterly. A standard warranty is provided on most of the Company's products over a specified period of time, generally 12 to 24 months, at no additional cost to its customers. Warranty charges are comprised of costs to service the warranty, including labor to repair the system and replacement parts for defective items, as well as other costs incidental to the repairs. Warranty charges are recorded net of any cost recoveries resulting from either successful repair of damaged parts or from warranties offered by the Company’s suppliers for defective components. Using historical data, the Company estimates average warranty cost per system or part type and records the provision for such charges as an element of cost of sales upon recognition of the related revenue. Additionally, the overall warranty accrual balance is separately analyzed using the remaining warranty periods outstanding on systems and items under warranty, and any resulting changes in estimates are recorded as an adjustment to cost of sales. If circumstances change, or if a significant change in warranty-related incidents occurs, the impact of the change in the warranty accrual could be material. Accrued product warranty is included on the Consolidated Balance Sheets as a component of accrued liabilities. Research and Development Research and development costs, which include labor and related employee expenses, patent maintenance fees, project materials costs, development tool placement and installation costs, project subcontractors, depreciation of engineering equipment, building costs and other administration expenses, are generally expensed as incurred. Engineering materials that are expected to provide future value are included in inventories. Income Taxes The Company accounts for income taxes under the asset and liability method. Under this method, deferred income taxes are recognized for the future tax consequences attributable to temporary differences between the financial statement and tax balances of existing assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those assets and liabilities are expected to be recovered or settled. The effect on deferred taxes resulting from a change in tax rates is recognized in income in the period that includes the enactment date. When management determines that it is not more likely than not that a deferred tax asset will be fully realized, a valuation allowance is established to reduce deferred tax assets to the amount expected to be realized. Comprehensive Income (Loss) Comprehensive income (loss) includes net income (loss) and other comprehensive income (loss), which includes charges or credits to equity that are not the result of transactions with shareholders. Comprehensive income (loss) comprised primarily of cumulative foreign currency translation adjustments, benefit plan obligations and unrealized gains and losses on securities available for sale. The cumulative translation adjustment included in accumulated other comprehensive income (loss) at March 31, 2018 and April 1, 2017 was $0.6 million and $(1.2) million , respectively. Earnings Per Share Basic earnings per share (EPS) is computed by dividing income available to common stockholders by the weighted average number of shares outstanding during the period. Diluted EPS also considers common stock equivalents, such as stock options, stock-settled stock appreciation rights (SARs), employee stock purchase plan (ESPP) shares and restricted stock units, to the extent that they are not antidilutive. Share-Based Compensation The Company recognizes expense related to the fair value of SARs and ESPP using the Black-Scholes model to estimate the fair value of awards on the date of grant. The fair value of time-based and performance-based restricted stock units (RSUs) are measured on the grant date based on the market value of the Company's common stock. The market-based RSUs must achieve the total shareholder return (TSR) measures in order for the awards to vest, and the grant date fair value of the awards is calculated using a Monte Carlo simulation model. Except performance-based RSUs, the Company recognizes compensation expense for all share-based compensation awards, net of estimated forfeitures, on a straight-line basis over the requisite service period of the award. Expense for performance-based RSUs is recognized based on the probability of achievement of the performance criteria. The compensation cost for market-based RSUs is recognized on a straight-line basis over the related service period, even if the market condition is never satisfied. Segment Reporting The Company complies with ASC Topic 280 Segment Reporting (ASC Topic 280). ASC Topic 280, which is based on a management approach to segment reporting, establishes requirements to report selected segment information quarterly and to report annually entity-wide disclosures about products, major customers and the geographies in which the entity holds material assets and reports revenue. An operating segment is defined as a component that engages in business activities whose operating results are reviewed by the chief operating decision maker and for which discrete financial information is available. Based on the provisions of ASC Topic 280, the Company has determined that it operates in a single segment. There is no difference between the accounting policies used for the segment compared to those used on a consolidated basis. Employee Benefit Plans The Company has an employee savings plan under the provisions of Section 401(k) of the Internal Revenue Code. During 2018 , 2017 and 2016 , contributions to the plan by the Company were $0.7 million, $0.8 million and $0.7 million, respectively. The Company has defined benefit retirement plans at certain of its foreign subsidiaries. The Company accounts for these plans based on the provisions of ASC Topic 715, Compensation-Retirement Benefits . These plans are immaterial to the financial statements of the Company taken as a whole.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Mar. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	opted accounting pronouncements: In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-09, Compensation – Stock Compensation – Improvements to Employee Share-Based Payment Accounting . ASU 2016-09 simplifies the accounting for several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, classification on the statement of cash flows, and the accounting for forfeitures. ASU 2016-09 was effective for the Company as of April 2, 2017, the beginning of fiscal 2018. ASU 2016-09 was adopted in the first quarter of 2018 and at the time it increased diluted weighted average shares outstanding by approximately 40 thousand shares due to the change in recognition of excess tax benefits in the calculation. The ASU is expected to increase the volatility of the Company's diluted shares outstanding on a go-forward basis. In July 2015, the FASB issued ASU 2015-11, Simplifying the Measurement of Inventory . ASU 2015-11 simplifies the measurement of inventory by requiring companies to measure inventory at the lower of cost and net realizable value rather than measuring at the lower of cost or market where the market value was determined based off of three different measures. ASU 2015-11 was effective for the Company as of April 2, 2017, the beginning of fiscal 2018. Adopting ASU 2015-11 has not had a material effect on the Company's inventory valuation. Recently issued accounting pronouncements not yet adopted In February 2018, the FASB issued ASU 2018-03, Technical Corrections and Improvements to Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities , which made six targeted amendments to ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10) Recognition and Measurement of Financial Assets and Financial Liabilities . These amendments mostly affect the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. Public business entities with annual periods beginning between December 15, 2017, and June 15, 2018, are not required to adopt these amendments until the interim period beginning after June 15, 2018, and public business entities with fiscal years beginning between June 15, 2018, and December 15, 2018, are not required to adopt these amendments before adopting the amendments in Update 2016-01. ASU 2018-03 would be applicable for the Company's second quarter of fiscal 2019 ending September 29, 2018. The Company does not expect the adoption of ASU 2018-03 to have a material effect on its financial position, results of operations or cash flows. In February 2018, the FASB issued ASU 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , in response the enactment of the Tax Cuts and Jobs Act and the subsequent questions and concerns of stakeholders regarding how to apply the changes to the income tax effects of deferred tax assets and liabilities sitting in accumulated other comprehensive income. The guidance eliminates the resulting stranded tax effects and improves the usefulness of the information reported to users of the financial statements. ASU 2018-02 is effective for annual periods beginning after December 15, 2018, and interim periods within those annual periods, which would be the Company's fiscal year ending March 28, 2020. Early adoption is permitted, including adoption in any interim period, for public business entities for reporting periods for which financial statements have not yet been issued.The Company expects the adoption of ASU 2018-02 to not have a material effect on its financial position, results of operations or cash flows. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities , in order to (i) improve disclosures related to an entity's risk management activities through better transparency and understandability and (ii) simplify and reduce the complexity of hedge accounting by preparers. ASU 2017-12 is effective for annual periods beginning after December 15, 2018, and interim periods within those annual periods, which would be the Company's fiscal year ending March 28, 2020. Early adoption is permitted, including adoption in any interim period, for public business entities for reporting periods for which financial statements have not yet been issued. While the Company does not expect the adoption of ASU 2017-12 to have a material effect on its business, the Company is still evaluating any potential impact that adoption of ASU 2017-12 may have on its financial position, results of operations or cash flows. In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting , which amends the scope of modification accounting surrounding share-based payment arrangements as issued in ASU 2016-09 by providing guidance on the various types of changes which would trigger modification accounting for share-based payment awards, specifically an entity would not apply modification accounting under ASC 718 if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. ASU 2017-09 is effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods, which would be the Company's fiscal year ending March 30, 2019. The adoption of ASU 2017-09 will not have a material effect on the Company's financial position, results of operations or cash flows. In March 2017, the FASB issued ASU 2017-07, Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost , which requires companies to disaggregate the current-service-cost component from other components of net benefit cost and provides specific guidance for presentation in the income statement. ASU 2017-07 is effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods, which would be the Company's fiscal year ending March 30, 2019. Early adoption is permitted as of the beginning of an annual period for which financial statements (interim or annual) have not been issued or made available for issuance. The adoption of ASU 2017-07 will not have a material effect on the Company's financial position, results of operations or cash flows. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers: Topic 606 (ASU 2014-09) , to supersede nearly all existing revenue recognition guidance under GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. The FASB has continued to issue ASU topics to further clarify ASU 2014-09. These have included ASU 2016-08, ASU 2016-10, ASU 2016-12, and ASU 2016-20. The new standards are effective for the Company's fiscal year ending March 30, 2019, beginning with the first quarter of that fiscal year. The new standard permits adoption by using either (i) a full retrospective approach for all periods presented in the period of adoption or (ii) a modified retrospective approach with the cumulative effect of initially applying the new standard recognized at the date of initial application and providing certain additional disclosures. The Company has elected the modified retrospective approach as its transition method. The Company developed an implementation plan and assigned cross-functional internal resources to perform a comprehensive assessment of the new standard and its impact on the financial statements of the Company. This assessment is largely complete and included identification, consideration, and quantification of the impact of the new standard on the Company's financial statements, accounting policies, processes, control environment and systems. The outcome of this evaluation will be the implementation of supporting processes and systems that enable timely and accurate reporting under the new standard. The Company believes that, based on its assessment, the new standard is likely to result in an immaterial change to the amount or timing of revenue recognition related to system sales or service contracts, the Company's major revenue streams. This assessment is based on the Company's analysis of actual historical revenue transactions and current customer contracts under the new guidance and presumes certain conclusions as it relates to accounting policies under the new standard and the Company's current contracts. Final quantification of the impact is ongoing and will be impacted by the specific contracts in place as of the date of transition, but the primary expected changes are described here. There may be some impact related to the allocation of value and timing of recognition in situations where service contracts, which the Company expects to be recognized over time, are sold together with systems that are primarily recognized at a point in time. Further, the treatment of contract assets and liabilities under the new standard is expected to result in the netting of certain items that have been historically presented gross on the Consolidated Balance Sheets, specifically shipped systems pending acceptance and deferred revenues. Lastly, in connection with the adoption of the standard, there is a requirement to capitalize certain costs, which for the Company primarily comprises commission expenses for sales representatives. Any such costs required to be capitalized would amortize over the period of performance for the underlying contracts. The Company is still evaluating the impact of capitalizing costs to execute a contract. However, the potential impact related to these costs would stem from commissions on service contracts with a duration approximating or exceeding one year. The impact related to contracts with a duration over one year is not expected to be significant, and the Company expects to elect the practical expedient under the new standard for costs with a duration less than one year and expense those items as incurred. The Company believes that certain aspects of the new guidance will require significant judgment, including identification of relevant performance obligations and quantification and allocation of the consideration to which the entity expects to be entitled in exchange for those goods or services. Due to the complexity of certain of the Company's contracts and the possibility that contractual arrangements could change, the actual revenue recognition treatment required under the new standard for these arrangements may be dependent on contract-specific terms and may vary from the Company's expectations. The Company currently expects that necessary operational changes will be implemented upon adoption. The new standard will increase the Company's revenue related disclosures, primarily by expanding disclosure of the Company's policies, significant estimates, and performance obligations. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory , to improve and simplify the accounting for the income tax consequences of intra-entity transfers of assets other than inventory, requiring companies to recognize income tax consequences upon the transfer of the asset to a third party. ASU 2016-16 is effective for the Company's fiscal year ending March 30, 2019. While the Company does not expect the adoption of ASU 2016-16 to have a material effect on its business, the Company is still evaluating any potential impact that adoption of ASU 2016-16 may have on its financial position, results of operations or cash flows. In February 2016, the FASB issued ASU 2016-02, Leases . ASU 2016-02 increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requires disclosing key information about leasing arrangements. ASU 2016-02 is effective for annual periods beginning after December 15, 2018 and interim periods within those annual periods, which would be the Company's fiscal year ending March 28, 2020. The Company is still evaluating any potential impact that adoption of ASU 2016-02 may have on its financial position, results of operations or cash flows.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	nancial Assets Measured at Fair Value The Company’s fair value hierarchy for its financial assets measured at fair value on a recurring basis as of March 31, 2018 and April 1, 2017 was as follows (in thousands): March 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents: Money market securities $ 41,752 $ — $ — $ 41,752 U.S. treasury fund 2,500 — — 2,500 Commercial paper — 3,498 — 3,498 Corporate bonds — 1,999 — 1,999 Total cash equivalents $ 44,252 $ 5,497 $ — $ 49,749 Short term investments - available for sale: U.S. treasury fund $ 10,458 $ — $ — $ 10,458 Commercial paper — 25,913 — 25,913 Corporate bonds — 10,750 — 10,750 Total short-term investments - available for sale $ 10,458 $ 36,663 $ — $ 47,121 Forward purchase or sale contracts: Japanese Yen $ — $ (23 ) $ — $ (23 ) New Taiwan Dollar — 3 — 3 Korean Won — (12 ) — (12 ) Euro — 7 — 7 British Pound — 49 — 49 Chinese Renminbi — (29 ) — (29 ) Singapore Dollar — (1 ) — (1 ) Total forward contracts $ — $ (6 ) $ — $ (6 ) Deferred compensation plan assets:* Mutual funds and exchange traded funds $ 1,841 $ — $ — $ 1,841 Money market securities 207 — — 207 Total deferred compensation plan assets $ 2,048 $ — $ — $ 2,048 *These investments represent assets held in trust for ESI's deferred compensation plan April 1, 2017 Level 1 Level 2 Level 3 Total Cash equivalents: Money market securities $ 22,395 $ — $ — $ 22,395 Commercial paper — 4,945 — 4,945 Total cash equivalents $ 22,395 $ 4,945 $ — $ 27,340 Short term investments - available for sale: Commercial paper $ — $ 5,743 $ — $ 5,743 Total short-term investments - available for sale $ — $ 5,743 $ — $ 5,743 Forward purchase or sale contracts: Japanese Yen $ — $ 9 $ — $ 9 New Taiwan Dollar — 20 — 20 Korean Won — 39 — 39 Euro — (96 ) — (96 ) Chinese Renminbi — (5 ) — (5 ) Singapore Dollar — (1 ) — (1 ) Total forward contracts $ — $ (18 ) $ — $ (18 ) Deferred compensation plan assets:* Mutual funds and exchange traded funds $ 845 $ — $ — $ 845 Money market securities 2,213 — — 2,213 Total deferred compensation plan assets $ 3,058 $ — $ — $ 3,058 *These investments represent assets held in trust for ESI's deferred compensation plan For Level 1 assets, the Company utilized quoted prices in active markets for identical assets. For Level 2 assets, exclusive of forward contracts, the Company utilized quoted prices in active markets for similar assets. For forward contracts, spot prices at March 31, 2018 and April 1, 2017 were utilized to calculate fair values. During 2018 and 2017 , there were no transfers between Level 1, 2 or 3 assets. Investments The Company’s investments, including the investments classified as cash equivalents, at March 31, 2018 and April 1, 2017 were as follows (in thousands): Unrealized March 31, 2018 Cost Gain Loss Fair Value Available-for-sale securities (current): U.S. treasury fund $ 12,975 $ — $ (17 ) $ 12,958 Commercial paper 29,411 — — 29,411 Corporate bonds 12,768 — (19 ) 12,749 Total investments (current) $ 55,154 $ — $ (36 ) $ 55,118 Available-for-sale securities (non-current): Mutual funds, exchange traded funds and money market securities* $ 1,881 $ 167 $ — $ 2,048 Total investments (non-current) $ 1,881 $ 167 $ — $ 2,048 Unrealized April 1, 2017 Cost Gain Loss Fair Value Available-for-sale securities (current): Commercial paper $ 10,688 $ — $ — $ 10,688 Total investments (current) $ 10,688 $ — $ — $ 10,688 Available-for-sale securities (non-current): Mutual funds, exchange traded funds and money market securities* $ 2,974 $ 84 $ — $ 3,058 Total investments (non-current) $ 2,974 $ 84 $ — $ 3,058 *These investments represent assets held in trust for ESI's deferred compensation plan For purposes of determining gross realized gains and losses and reclassification out of accumulated other comprehensive income (loss), the cost of securities sold is based on specific identification. Net unrealized holding gains and losses on current available-for-sale securities included in accumulated other comprehensive income (loss) were insignificant as of March 31, 2018 and April 1, 2017 .

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Company enters into derivative financial instruments on a limited basis and does not use them for trading purposes. It does, however, use derivatives in the form of forward exchange contracts to manage well-defined foreign currency risks. The Company enters into economic hedges of material non-functional currency monetary asset and liability balances. Foreign exchange contract gains and losses are recognized at the end of each fiscal period in the Company’s results of operations. Such gains and losses are typically offset by the corresponding changes to the related underlying hedged item. Cash flows from derivative financial instruments are classified in the same category as the cash flows from the items hedged. At March 31, 2018 and April 1, 2017 , the Company had net forward exchange contracts to purchase foreign currencies totaling $10.6 million and $7.3 million , respectively. In general, these contracts have a duration of approximately one month and the counterparties are large, highly rated banks; therefore, the Company believes that the risk of loss as a result of nonperformance by the banks is minimal. The table below summarizes, by currency, the notional amounts of forward exchange contracts in U.S. dollars as of March 31, 2018 and April 1, 2017 . The “bought” amounts represent the net U.S. dollar equivalents of commitments to purchase foreign currencies, and the “sold” amounts represent the net U.S. dollar equivalents of commitments to sell foreign currencies. The foreign currency amounts have been translated into a U.S. dollar equivalent value using the exchange rates as of March 31, 2018 and April 1, 2017 . Bought (Sold) (In thousands) 2018 2017 Japanese Yen $ 5,456 $ 1,352 Euro 6,613 7,568 New Taiwan Dollar (1,546 ) (686 ) Korean Won (218 ) 32 British Pound (3,031 ) (1,992 ) Chinese Renminbi 2,665 995 Singapore Dollar 659 74 $ 10,598 $ 7,343

Trade Receivables, net (Notes)

Trade Receivables, net (Notes)	12 Months Ended
	Mar. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	Trade accounts receivable at March 31, 2018 and April 1, 2017 consisted of the following: (In thousands) 2018 2017 Current trade accounts receivable, net $ 63,044 $ 40,494 Non-current trade accounts receivable — 489 $ 63,044 $ 40,983 Non-current trade accounts receivable are included in Other assets in the Consolidated Balance Sheets.

Inventories

Inventories	12 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Inventories	e components of inventories at March 31, 2018 and April 1, 2017 were as follows: (In thousands) 2018 2017 Raw materials and purchased parts $ 52,591 $ 41,383 Work-in-process 18,634 13,829 Finished goods 16,461 3,730 $ 87,686 $ 58,942 In 2018 , 2017 and 2016 , the Company recorded charges to cost of sales for inventory write-offs associated with discontinued products of $8.2 million , $1.7 million and $1.4 million , respectively. The 2018 write-offs primarily relate to the restructuring which began in the fourth quarter of 2017 and continued into 2018. Additionally, in 2017, $0.9 million of inventory write-off was recorded for flood damaged inventory at the Company's Wuhan manufacturing facility. See Note 22: Restructuring and Cost Management Plans for further discussion on discontinued product costs.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	perty, plant and equipment as of March 31, 2018 and April 1, 2017 consisted of the following: (In thousands) Weighted Average 2018 2017 Land n/a $ 2,152 $ 2,152 Buildings and improvements 18 38,467 36,204 Machinery and equipment 5 41,889 59,099 Computer equipment and software 5 22,676 36,239 105,184 133,694 Less accumulated depreciation (83,159 ) (112,075 ) $ 22,025 $ 21,619 Depreciation expense totaled $5.9 million, $6.9 million and $6.8 million in 2018 , 2017 and 2016 , respectively. For the year ended March 31, 2018 , the Company performed a review for impairment based on certain triggering events. As a result of this review, no impairments of property, plant and equipment were identified. Additionally, in 2018 the Company recorded impairment charges of $1.7 million associated with completion of the 2017 restructuring plan in 2018. See Note 22: Restructuring and Cost Management Plans for further discussion.

Acquired Intangible Assets

Acquired Intangible Assets	12 Months Ended
	Mar. 31, 2018
Intangible Assets Disclosure [Abstract]
Acquired Intangible Assets	uired intangible assets as of March 31, 2018 and April 1, 2017 consisted of the following: (In thousands, except years) Weighted 2018 2017 Developed technology 7.5 $ 18,646 $ 18,646 Customer relationships 5.3 3,914 3,914 Customer backlog 1.0 1,270 1,270 Trade name and trademarks 3.8 793 793 Fair value of below-market lease (non-current portion) 3.8 310 310 Change of control agreements and non-compete agreements 2.1 160 160 Patents 12.7 2,842 3,465 27,935 28,558 Less accumulated amortization (22,766 ) (21,994 ) $ 5,169 $ 6,564 Amortization expense for acquired intangible assets has been recorded in the Consolidated Statements of Operations as follows: (In thousands) 2018 2017 2016 Cost of sales $ 977 $ 1,133 $ 1,140 Selling, general and administration 208 209 36 Research, development and engineering 188 188 200 $ 1,373 $ 1,530 $ 1,376 The estimated amortization expense for acquired intangible assets in future years is as follows (in thousands): Year Amortization 2019 $ 1,427 2020 1,404 2021 1,245 2022 695 2023 298 Future years 100 $ 5,169

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Mar. 31, 2018
Disclosure Accrued Liabilities [Abstract]
Accrued Liabilities	Accrued liabilities (current) consisted of the following at March 31, 2018 and April 1, 2017 : (In thousands) 2018 2017 Payroll-related liabilities $ 15,879 $ 6,335 Restructuring and cost management amounts payable 429 4,996 Product warranty accrual 4,646 3,394 Purchase order commitments and receipts 2,978 2,522 Customer deposits 2,214 1,242 Professional fees payable 778 734 Current portion, long-term debt 421 434 Other current liabilities 7,188 2,529 $ 34,533 $ 22,186 Included in other liabilities above are accrued amounts for value-added taxes, income taxes, commissions payable to external representatives, freight and other similar items.

Product Warranty

Product Warranty	12 Months Ended
	Mar. 31, 2018
Product Warranties Disclosures [Abstract]
Product Warranty	following is a reconciliation of the changes in the aggregate product warranty accrual for 2018 , 2017 and 2016 : (In thousands) 2018 2017 2016 Product warranty accrual, beginning $ 5,474 $ 5,734 $ 3,342 Warranty charges incurred, net (11,247 ) (8,297 ) (7,781 ) Provision for warranty charges 15,993 8,037 10,173 Product warranty accrual, ending $ 10,220 $ 5,474 $ 5,734 Net warranty charges incurred include labor charges and costs of replacement parts for system repairs under warranty. These costs are recorded net of any estimated cost recoveries resulting from either successful repair of damaged parts or from warranties offered by the Company’s suppliers for defective components. The provision for warranty charges reflects the estimate of future anticipated net warranty costs to be incurred for all products under warranty at fiscal year-end and is recorded to cost of sales. Of the total of $10.2 million and $5.5 million in product warranty accrual at March 31, 2018 and April 1, 2017 , $5.6 million and $2.1 million were non-current and were included in Other liabilities on the Consolidated Balance Sheets.

Deferred Revenue

Deferred Revenue	12 Months Ended
	Mar. 31, 2018
Deferred Revenue Disclosure [Abstract]
Deferred Revenue	following is a reconciliation of the changes in deferred revenue for 2018 , 2017 and 2016 : (In thousands) 2018 2017 2016 Deferred revenue, beginning $ 15,397 $ 7,685 $ 12,376 Revenue deferred 82,394 43,379 58,416 Revenue recognized (87,277 ) (35,667 ) (63,107 ) Deferred revenue, ending $ 10,514 $ 15,397 $ 7,685 Of the total of $10.5 million , $15.4 million , and $7.7 million in deferred revenue at March 31, 2018 , April 1, 2017 and April 2, 2016 , $0.7 million , $0.7 million and $1.3 million is non-current and is included in Other liabilities on the Consolidated Balance Sheets.

Revolving Credit Facility (Note

Revolving Credit Facility (Notes)	12 Months Ended
	Mar. 31, 2018
Line of Credit Facility [Line Items]
Debt Disclosure [Text Block]	The Company is party to a loan and security agreement (Credit Facility) with Silicon Valley Bank, which was initially entered into on March 20, 2015 and amended on July 12, 2016. The Credit Facility provides for a senior secured asset-based revolving facility with availability up to $30 million , including a $15 million sublimit for letters of credit. The Credit Facility expires March 20, 2019. At March 31, 2018, the Company had no amounts outstanding under the Credit Facility, was in compliance with all covenants, and was not in default under the Credit Facility. The commitment fee on the amount of unused credit was 0.3 percent. If the Company fails to meet the covenants in its Credit Facility or its lenders fail to fund, access to the facility may be limited or the facility may become unavailable altogether.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	aggregate minimum commitment obligation under operating leases beyond March 31, 2018 was as follows (in thousands): Year Operating Leases 2019 $ 2,504 2020 2,080 2021 1,513 2022 902 2023 199 Thereafter 585 $ 7,783 The Company leases certain equipment, automobiles, manufacturing and office space under operating leases, which are non-cancelable and expire on various dates through the first quarter of 2027. Rental expense for all operating leases was $2.4 million , $2.6 million and $2.5 million in 2018 , 2017 and 2016 , respectively. The operating lease amounts include the contractual facility lease obligations at the Company's Singapore; Bordeaux, France; Shanghai, China; and Dongtan, Korea sites. The Company routinely enters into inventory purchase contracts which require purchase commitments. As a result, if the Company experiences lower than anticipated demand for its products, in many cases it would not be able to avoid the cost of purchasing the associated inventory, which could negatively impact its results of operations and liquidity. The Company had purchase commitments of $84.3 million at March 31, 2018 , up significantly from previous years primarily due to increased production levels. Of these commitments, $7.9 million represent long term purchase contracts.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	re Repurchase Program In December 2011, the Board of Directors authorized a share repurchase program totaling $20.0 million to acquire shares of the Company's outstanding common stock. The repurchases are to be made at management’s discretion in the open market or in privately negotiated transactions in compliance with applicable securities laws and other legal requirements and are subject to market conditions, share price and other factors. The Company did not repurchase any shares during 2018 , 2017 or 2016 . There is no fixed completion date for the repurchase program.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	e Company's employee share-based compensation plans consist of its 2004 Stock Incentive Plan (the 2004 Plan) and the ESPP. The 2004 plan, as amended, has been approved to reserve a total of 4,750,000 shares of common stock for issuance to employees and directors of the Company. It allows for grants of stock options, stock appreciation rights; stock bonuses; RSUs including time-based, performance-based, and market-based RSU awards; and dividend equivalents. The ESPP, as approved, reserves 5,400,000 shares of common stock for issuance to participating employees. Eligible employees may elect to contribute up to 15 percent of their base wage and commissions during each pay period. As of the second quarter of 2018, new offerings are for six month periods with a maximum of 1,000 shares per purchase date with each new offering beginning on February 15 or August 15 of each year. At the end of each offering period, the purchase price is determined and the accumulated funds are used to automatically purchase shares of common stock. The purchase price per share is equal to 85 percent of the lower of the fair market value of the common stock on (a) the first day of the offering period or (b) the date of purchase. Previously, employees could purchase up to a maximum of 500 shares per purchase date and the ESPP provided for separate overlapping twenty-four month offerings starting every three months. The Company has a small minority of employees still purchasing under the three month offering period plan. SARs grant the right to receive shares of the Company's stock equivalent to the increase in stock value of a specified number of shares over a specified period of time, divided by the stock price at the time of exercise. RSU's grant the right to receive a set number of shares on the vest date, assuming all criteria have been met and continued service through the vest date. Time-based RSU's vest solely based on continued service through the vest date. Performance-based RSU's are earned based on specifically stated performance criteria in the grant agreement. Market-based RSUs must achieve the TSR measures based on the Company's stock performance relative to a stated index. See Note 2: Summary of Significant Accounting Policies for further discussion concerning the Company's policies for recognizing compensation expense for these awards. Share-based compensation expense was included in the Company’s Consolidated Statements of Operations as follows: (In thousands) 2018 2017 2016 Cost of sales $ 277 $ 503 $ 445 Selling, general and administration 3,657 5,197 3,004 Research, development and engineering 679 737 783 Share-based compensation expense $ 4,613 $ 6,437 $ 4,232 The total amount of net cash used related to stock plan awards in 2018 was $0.7 million , in 2017 and 2016 net cash received was $0.5 million and $0.7 million . All stock plan awards are settled with newly issued shares. No share-based compensation costs were capitalized during 2018 , 2017 or 2016 . As of March 31, 2018 , the Company had $7.4 million of total unrecognized share-based compensation costs, net of estimated forfeitures, which are expected to be recognized over a weighted average period of 2.1 years . Valuation Assumptions The Black-Scholes pricing model is utilized to determine the fair value of SARs granted and ESPP issued. No SARs were granted in 2018 and 2017 . The following weighted average assumptions were used in calculating the grant date fair value of SARs during the periods presented: 2018 2017 2016 Risk-free interest rate — % — % 1.94 % Expected lives 0.0 years 0.0 years 7.4 years Expected volatility — % — % 47 % The following weighted average assumptions were used to estimate the fair value of ESPP shares issued in the periods presented: 2018 2017 2016 Risk-free interest rate 1.37 % 0.68 % 0.34 % Expected lives 0.6 years 1.1 years 1.1 years Expected volatility 55 % 45 % 35 % The risk-free interest rates used are based on the U.S. Treasury yields over the expected terms. The fair value of time-based RSUs and performance-based RSUs are measured on the grant date based on the market value of the Company's common stock. The market-based RSUs must achieve the TSR measures in order for the awards to vest, and the grant date fair value of the awards is calculated using a Monte Carlo simulation model. The assumptions used in the Monte Carlo simulation includes the risk free rate, expected divided yield, expected term, and possible future stock prices over the performance period based on historical stock and market prices. At March 31, 2018 , the Company had 6,767,223 shares of its common stock reserved for issuance under all of the above plans combined. Of those shares, 1,606,815 are subject to issuance under currently outstanding stock options, SARs and stock awards and 5,160,408 shares, including 999,091 shares available for issuance under the ESPP, are available for future grants. In addition to standard forfeitures, 817 thousand shares were returned to the pool of shares available for issuance due to SAR exercises. The total fair value of stock option and SAR awards granted and vested during the period, restricted stock unit awards granted and vested during the period, the intrinsic value of stock options and SARs exercised during the period and the total grant date fair value were: (In thousands, except per share data) 2018 2017 2016 Stock-Option and SAR Awards: Grant date fair value per share $ — $ — $ 2.89 Total fair value of options and SARs granted — — 1,350 Total fair value of options and SARs vested 755 820 336 Total intrinsic value of options and SARs exercised 6,641 17 1 Restricted Stock Unit Awards: Grant date fair value per share 10.59 6.71 5.52 Total fair value of awards granted 7,084 11,382 4,072 Total fair value of awards vested 4,945 3,693 4,324 Employee Stock Purchase Plan: Grant date fair value per share 2.14 1.40 1.22 Total grant date fair value 613 473 394 Share-Based Payment Award Activity Information with respect to stock option and SAR activity was as follows: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at March 28, 2015 2,229,046 $ 12.52 Granted 467,000 5.63 Exercised (2,500 ) 6.71 Expired or forfeited (537,946 ) 16.53 Outstanding at April 2, 2016 2,155,600 $ 10.03 5.35 $ 904 Granted — — Exercised (22,500 ) 6.23 Expired or forfeited (191,097 ) 19.20 Outstanding at April 1, 2017 1,942,003 $ 9.17 4.82 $ 634 Granted — — Exercised (1,280,478 ) 8.17 Expired or forfeited (548,000 ) 11.92 Outstanding at March 31, 2018 113,525 $ 7.26 4.17 $ 1,371 Vested and expected to vest at March 31, 2018 113,140 $ 7.26 4.16 $ 1,365 Exercisable at March 31, 2018 89,525 $ 7.64 3.42 $ 1,046 Information with respect to time-based restricted stock unit awards activity was as follows: Shares Weighted Weighted Average Remaining Contractual Term (In years) Aggregate Outstanding at March 28, 2015 835,841 $ 8.90 Awarded 737,200 5.52 Vested (360,349 ) 11.75 Forfeited (130,888 ) 7.66 Outstanding at April 2, 2016 1,081,804 $ 6.77 1.93 $ 7,781 Awarded 1,051,445 6.63 Vested (483,239 ) 7.64 Forfeited (42,093 ) 6.67 Outstanding at April 1, 2017 1,607,917 $ 6.41 2.04 $ 11,168 Awarded 446,400 9.81 Vested (757,462 ) 6.53 Forfeited (396,830 ) 6.83 Outstanding at March 31, 2018 900,025 $ 7.82 2.39 $ 17,397 Information with respect to performance-based and market-based restricted stock unit awards activity was as follows: Shares Weighted Weighted Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at March 28, 2015 593,704 $ 7.88 Awarded — — Vested (1) (5,592 ) 14.64 Forfeited (187,125 ) 10.84 Outstanding at April 2, 2016 400,987 $ 6.93 1.00 $ 2,928 Awarded 643,565 6.85 Vested (1) — — Forfeited (400,987 ) 6.93 Outstanding at April 1, 2017 643,565 $ 6.85 2.43 $ 4,409 Awarded 222,400 12.17 Vested (1) — — Forfeited (272,700 ) 7.27 Outstanding at March 31, 2018 593,265 $ 8.76 1.78 $ 11,468 (1) Zero performance-based or market-based shares were earned in 2017 and 2016 . Based on 2018 performance, the Company believes 182,671 market-based shares and zero performance-based shares were earned.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Mar. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	The sum of the quarterly data presented in the table above for fiscal 2018 and 2017 may not equal annual results due to rounding. 1. In the fourth quarter of 2018, net income included $41.2 million favorable impact due to the release of tax valuation allowance (See Note 23: Income Taxes ). 2. In the first and second quarters of 2018, gross profit included $13.3 million of charges for inventory and other asset write-offs related to restructuring activities (See Note 22: Restructuring and Cost Management Plans ). 3. In the fourth quarter of 2017, gross profit included $2.3 million of charges for intangible write-off (See Note 12: Accrued Liabilities ) and $1.7 million of charges in inventory write-off related to discontinued products (See Note 22: Restructuring and Cost Management Plans ). 4. In the fourth quarter of 2017, net operating expenses included a non-cash goodwill impairment charge of $7.4 million (See Note 9: Goodwill ) and $6.6 million of restructuring charges related to the Q4 2017 Corporate restructuring plan (See Note 22: Restructuring and Cost Management Plans ).

(Loss) Earnings Per Share

(Loss) Earnings Per Share	12 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
(Loss) Earnings Per Share	following was a reconciliation of weighted average shares outstanding used in the calculation of basic and diluted earnings (loss) per share for 2018 , 2017 and 2016 : (In thousands, except per share data) 2018 2017 2016 Net income (loss) $ 116,223 $ (37,409 ) $ (12,257 ) Weighted average shares used for basic earnings per share 33,967 32,551 31,411 Incremental diluted shares 1,604 — — Weighted average shares used for diluted earnings per share 35,571 32,551 31,411 Net income (loss) per share: Basic $ 3.42 $ (1.15 ) $ (0.39 ) Diluted $ 3.27 $ (1.15 ) $ (0.39 ) Awards of options, SARs and unvested restricted stock units representing an additional 0.3 million , 2.0 million and 2.3 million shares of stock for 2018 , 2017 and 2016 , respectively, were not included in the calculation of diluted net earnings per share because their effect would have been antidilutive.

Income Taxes

Income Taxes	12 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	t deferred tax assets and liabilities at March 31, 2018 and April 1, 2017 consisted of the following: (In thousands) 2018 2017 Deferred tax assets and liabilities: Inventory valuation and warranty costs $ 7,904 $ 11,246 Receivables and other non-current assets (49 ) (274 ) Payroll-related accruals 5,130 7,574 Intangible assets and investments (272 ) (382 ) Accrued liabilities 2,322 3,006 Deferred revenue 821 3,478 Property, plant and equipment 3,142 5,029 Other comprehensive income 3 456 Tax loss and credit carryforwards, net of unrecognized tax benefits 43,201 73,805 Other (liabilities) assets (185 ) 259 Total deferred tax assets 62,017 104,197 Valuation allowance (18,499 ) (103,315 ) Net deferred tax assets $ 43,518 $ 882 The Company had approximately $57.4 million and $84.7 million in tax assets resulting from federal, state and foreign net operating losses and tax credits as of March 31, 2018 and April 1, 2017 , respectively as follows: (In thousands) 2018 2017 Federal net operating losses $ 5,071 $ 35,566 State net operating losses 1,868 3,679 Foreign operating losses and tax credits 17,826 12,504 Federal research credits 24,127 22,590 State research credits 5,438 4,409 Federal minimum tax credit — 935 Federal capital losses 3,039 5,015 $ 57,369 $ 84,698 The federal and state net operating losses expire on various dates through fiscal 2039. The majority of the foreign tax credits expire on various dates through fiscal 2029. The federal and most of the state research credits expire on various dates through fiscal 2039. Certain state research credits and the federal minimum tax credits are available indefinitely. The state net operating losses and credits are reflected net of their federal tax impact. A valuation allowance is required if it is more likely than not that all or a part of a deferred tax asset will not be realized in the future. A valuation allowance of $18.5 million and $103.3 million existed as of March 31, 2018 and April 1, 2017 , respectively. The $84.8 million decrease in valuation allowance in 2018 was due to (1) the release of $42.3 million of valuation allowance resulting from positive evidence of future utilization of existing deferred tax assets, including three years of cumulative pre-tax income; (2) the utilization of $24.9 million of net operating losses in 2018; and (3) changes in the statutory tax rate caused by the Tax Act, which drove a further reduction in the allowance of $17.6 million related to the revaluation of deferred tax assets at the new statutory rate. The remaining valuation allowance relates to assets that are expected to expire prior to utilization, primarily foreign and state-related tax credits, and expiring capital loss carryforwards. The components of income before income taxes and the (benefit from) provision for income taxes, all from continuing operations, were as follows: (In thousands) 2018 2017 2016 Income (loss) before income taxes: Domestic $ 61,539 $ (32,646 ) $ (13,385 ) Foreign 14,414 (4,786 ) 1,112 Total income (loss) before income taxes $ 75,953 $ (37,432 ) $ (12,273 ) Provision for (benefit from) income taxes: Current: U.S. federal and state $ (248 ) $ (379 ) $ 8 Foreign 2,614 557 916 Total current 2,366 178 924 Deferred: U.S. federal and state (42,329 ) — — Foreign (307 ) (201 ) (940 ) Total deferred (42,636 ) (201 ) (940 ) Total benefit from income taxes $ (40,270 ) $ (23 ) $ (16 ) The portion of the tax benefit derived from stock-based compensation that is allocated as common stock was zero in 2018 , 2017 and 2016 . A reconciliation of the Company’s effective tax rate to the United States federal statutory income tax rate was as follows: 2018 2017 2016 U.S. federal statutory income tax rate 31.5 % 35.0 % 35.0 % State income taxes, net of federal benefit 3.7 (0.3 ) (0.5 ) Tax credits (4.5 ) 4.2 17.1 Non-U.S. income taxed at different rates (3.3 ) (0.9 ) 14.3 Changes in unrecognized tax benefits 4.5 (0.3 ) (4.1 ) Change in valuation allowance (111.2 ) (25.0 ) (51.8 ) Stock compensation (3.3 ) (2.6 ) (10.2 ) Intangible write-off — (5.1 ) — Acquisitions — (5.9 ) — Change in Rate 22.5 — — Mandated Repatriation of Foreign Earnings 9.0 — — Other, net (1.9 ) 1.0 0.3 Effective tax rate (53.0 )% 0.1 % 0.1 % The Company operates globally but considers its significant tax jurisdictions to include Canada, China, France, Japan, Korea, Singapore, Taiwan, the United Kingdom and the United States. The Company currently benefits from a tax incentive program in Singapore pursuant to which it pays no Singapore income tax with respect to its manufacturing income. The incentive period ends on June 30, 2021. The Company provides for income taxes on its foreign subsidiaries’ taxable income based on the effective income tax rate in each respective jurisdiction. Prior to 2018, the Company provided for deferred taxes on the undistributed earnings of a subsidiary, except to the extent that the income is intended to be indefinitely reinvested or remitted in a tax-free liquidation. The Tax Act required a deemed repatriation of earnings at a reduced rate to transition from a worldwide to a territorial tax regime. The Company recognized $19.5 million in taxable income as a result of the deemed dividend and reversed the deferred taxes on previously undistributed earnings. Prior to 2018, the foreign jurisdictions where the Company was permanently reinvested included Singapore and China (Wuhan Topwin Optoelectronics Technology Co., Ltd.). Due to the changes from the Tax Act, the Company no longer intends to permanently reinvest earnings. As of March 31, 2018 , the following tax years remained subject to examination by the major tax jurisdictions indicated: Major Jurisdictions Open Tax Years Canada 2011 and forward China 2008 and forward France 2015 and forward Japan 2011 and forward Korea 2013 and forward Singapore 2012 and forward Taiwan 2013 and forward United Kingdom 2014 and forward United States 2004 and forward A reconciliation of the beginning and ending amount of the consolidated liability for unrecognized income tax benefits for the years ended March 31, 2018 , April 1, 2017 and April 2, 2016 was as follows: (In thousands) 2018 2017 2016 Beginning unrecognized tax benefits balance $ 10,744 $ 10,385 $ 9,654 Gross increases for tax positions of prior years 2,909 62 731 Gross decreases for tax positions of prior years (397 ) (242 ) — Gross increases for tax positions for current year 1,060 539 — Ending unrecognized tax benefits balance $ 14,316 $ 10,744 $ 10,385 The unrecognized tax benefits were presented as long-term income taxes payable on the Consolidated Balance Sheets or netted against deferred tax assets, where applicable. If recognized, the net impact to the effective tax rate associated with the unrecognized tax benefits would be $0.1 million and zero as of March 31, 2018 and April 1, 2017 , respectively. The Company records interest and penalties related to unrecognized tax benefits as tax expense. The interest and penalties were minimal in 2018 , 2017 and 2016 . The Company does not expect a decrease in unrecognized tax benefits within the next twelve months due to a lapse in statute of limitations. The Company also expects the annual increases to be consistent with prior years and does not anticipate any significant changes in unrecognized tax benefits in the next twelve months as the result of examinations.

Legal Proceedings

Legal Proceedings	12 Months Ended
	Mar. 31, 2018
Disclosure Legal Proceedings [Abstract]
Legal Proceedings	In the ordinary course of business, the Company is involved in various legal matters, either asserted or unasserted. In the opinion of management, ultimate resolution of these matters will not have a material effect on the Company's consolidated financial position, results of operations or cash flows. *****

Restructuring and Cost Manageme

Restructuring and Cost Management Plans	12 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Restructuring and Cost Management Plans	2017 Corporate Restructuring: In the fourth quarter of 2017, the Company initiated a restructuring plan to improve business effectiveness and streamline operations to achieve a stated target profit level for the Company as a whole. As a part of the restructuring plan, the management team was reorganized from a business unit to a functional structure; the Company closed facilities in Montreal, Canada; Napa, California; and Sunnyvale, California; the Company discontinued certain products; and the Company made select reductions in headcount across the Company. Actions under this plan were completed as of the end of the third fiscal quarter of 2018. Total expenses related to the plan were $17.1 million in 2018 and $7.6 million in the fourth quarter of 2017. Included in the 2018 expenses are approximately $13.3 million of charges impacting gross margins, all incurred in the first and second quarters of 2018, primarily related to impairment of other assets and inventory stemming from the product portfolio program reviews which resulted in discontinuing certain products. Operating expense charges included $2.3 million of facilities and fixed assets charges related to streamlining facilities and discontinued products and $1.3 million of employee severance and related costs. Product portfolio reviews related to the restructuring plan were completed as of the end of the third quarter of 2018. The impacts of the decisions made in the portfolio reviews involve the use of certain estimates. Actual results could differ from those estimates and result in additional charges. The following table presents the total expected restructuring costs as of March 31, 2018 (in thousands): Total Expected Costs for the Plan Costs Recognized from Inception of the Plan Through the Year Ended March 31, 2018 Remaining Costs to be Recognized Subsequent to March 31, 2018 Employee severance and related personnel costs $ 4,925 $ 4,925 $ — Site closure costs 1,516 1,516 — Current asset impairments and other gross profit charges (1) 14,947 14,947 — Non-current asset impairments 3,033 3,033 — Other Costs 239 239 — Total $ 24,660 $ 24,660 $ — (1) Current asset impairments include inventory charges recorded in cost of sales. The following table presents the amounts payable related to the 2017 Corporate Restructuring (in thousands): Employee severance and related personnel costs Site closure costs Current asset impairments and other gross profit charges (1) Non-current asset impairments Other Costs Total Balance as of April 2, 2016 $ — $ — $ — $ — $ — $ — Costs incurred 3,588 888 1,669 1,376 66 7,587 Cash payments (341 ) — — — (66 ) (407 ) Non-cash items — — (1,669 ) (1,376 ) — (3,045 ) Balance as of April 1, 2017 $ 3,247 $ 888 $ — $ — $ — $ 4,135 Costs incurred 1,337 627 13,278 1,657 175 17,074 Cash (payments) receipts (4,445 ) (1,515 ) (2,402 ) 32 (175 ) (8,505 ) Non-cash items — — (10,876 ) (1,689 ) — (12,565 ) Balance as of March 31, 2018 $ 139 $ — $ — $ — $ — $ 139 (1) Asset and facilities costs include inventory charges recorded in cost of sales. Other restructuring plans: The Company's previously disclosed restructuring plans are largely complete. Net restructuring costs related to these plans were $0.4 million in 2018 and $0.4 million in 2017 . The amounts payable of $0.3 million at March 31, 2018 are expected to be future cash outflows, primarily relating to facility costs to be paid through the end of calendar 2018. The Company does not expect to incur additional expenses related to these plans. The following table presents the amounts related to restructuring and costs payable (in thousands): Restructuring & cost management amounts payable as of March 28, 2015 $ 1,997 Cash payments and other adjustments (4,064 ) Costs incurred 2,824 Restructuring & cost management amounts payable as of April 2, 2016 757 Cash payments and other adjustments (297 ) Costs incurred 401 Restructuring & cost management amounts payable as of April 1, 2017 861 Cash payments and other adjustments (980 ) Costs incurred 409 Restructuring & cost management amounts payable as of March 31, 2018 $ 290 Overall restructuring reserve: As of March 31, 2018 and April 1, 2017 , the amount of unpaid restructuring costs included in accrued liabilities on the Consolidated Balance Sheets were $0.4 million and $5.0 million , respectively. Included in the payable balance are amounts for severance and employee benefits, asset retirement obligation and net lease commitments.

Product and Geographic Informat

Product and Geographic Information	12 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Product and Geographic Information	erating segments are defined as components of an enterprise about which separate financial information is available and evaluated regularly by the chief operating decision maker (CODM) in deciding how to allocate resources and in assessing performance. The Company's CODM is its Chief Executive Officer (CEO). The Company and its consolidated subsidiaries operate in a single segment, defined as a manufacturer of high-technology microfabrication and related equipment. This segment sells products into a variety of end markets that are grouped into four major categories for the purpose of providing an understanding of the principal end markets for the products manufactured by the Company, specifically: 1) Printed Circuit Board (PCB), 2) Component Test, 3) Semiconductor, and 4) Industrial Machining. The following table presents net sales information by the four major product categories addressed by the Company's single segment: (In thousands) 2018 2017 2016 Printed Circuit Board $ 256,430 $ 88,771 $ 94,121 Component Test 32,790 22,381 19,901 Semiconductor 55,171 29,557 38,262 Industrial Machining 23,493 20,314 32,107 $ 367,884 $ 161,023 $ 184,391 Net sales by geographic area, based on the location of the end user, were as follows: (In thousands) 2018 2017 2016 Asia $ 332,499 $ 134,394 $ 152,259 Americas 19,241 16,378 21,206 Europe 16,144 10,251 10,926 $ 367,884 $ 161,023 $ 184,391 Long-lived assets; exclusive of investments, restricted cash and deferred taxes; by geographic area were as follows: (In thousands) 2018 2017 Americas $ 22,057 $ 32,234 Asia 13,811 8,111 Europe 5,591 5,648 $ 41,459 $ 45,993

Business Acquisitions

Business Acquisitions	12 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Business Acquisitions	Fiscal 2017 On August 1, 2016, the Company acquired all of the outstanding shares of Visicon Technologies, Inc. (Visicon), a leading supplier of high-accuracy and high-throughput measurement and defect detection systems based in Napa, California. The consideration under the merger agreement is subject to adjustment for indebtedness, seller's transaction expenses, working capital and other items. Based on closing working capital and other adjustments, the Company paid $2.0 million in cash and issued 603,939 shares of ESI common stock, valued at approximately $4.2 million . The value of the common stock was based on the closing price of stock on August 1, 2016. A portion of the shares issued in connection with the agreement were reserved in escrow to serve as a source of payment for any purchase price adjustments or indemnity claims by the Company. The shares issued as a part of this merger represented a non-cash investing activity of $4.2 million . The total purchase price of $6.2 million , net of cash acquired, was allocated to the underlying assets acquired and liabilities assumed based on relative fair value, as shown in the following table: (In thousands) Accounts receivable $ 391 Inventory 982 Prepaid expense and other current assets 116 Property, plant and equipment 737 Acquired intangibles 3,300 Goodwill 2,626 Other assets 26 Accounts payable and other accrued liabilities (1,952 ) Total purchase price, net of cash acquired $ 6,226 The acquisition provided the Company with complementary defect detection technology for integrated verification of laser machining and an expanded presence in the medical device market, resulting in synergies with the Company's current consumer electronics customer base. None of the goodwill was deductible for tax purposes. The acquired intangible assets consisted primarily of approximately $2.1 million of developed technology. Identified intangible assets are expected to be amortized over their useful lives of one to six years. The operating results of the acquired entity are included in the Company’s results of operations since the date of acquisition. Pro forma financial information has not been provided for the acquisition of Visicon as it is not material to the Company’s operations and financial position. Fiscal 2015

Subsequent Events

Subsequent Events	12 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated subsequent events from balance sheet date through the date at which the financial statements were issued, and determined there are no other material items to disclose.

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of presentation	The accompanying Consolidated Financial Statements include the accounts of Electro Scientific Industries, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated. The Company’s fiscal year consists of 52 or 53 week periods ending on the Saturday nearest March 31. Accordingly, the fiscal 2018 reporting period consisted of a 52 -week period ending on March 31, 2018 , the fiscal 2017 reporting period consisted of a 52 -week period ending on April 1, 2017 and the fiscal 2016 reporting period consisted of a 53 -week period ending on April 2, 2016 . All references to years or quarters relate to fiscal years or fiscal quarters unless otherwise noted.
Estimates	The preparation of Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of commitments and contingencies at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results may differ from those estimates. Management believes that the estimates used are reasonable. Estimates made by management include: revenue recognition; inventory valuation; valuation of investments; accrued restructuring costs; share-based compensation; income taxes, including the valuation of deferred tax assets; valuation of long-lived assets, including intangibles; goodwill and acquisition accounting.
Cash equivalents	All highly liquid investments with a maturity of 90 days or less at the date of purchase are considered to be cash equivalents.
Investments	Short-term investments reflect marketable securities that have maturities of less than one year or are subject to immediate pre-payment or call provisions. These securities consist primarily of marketable debt securities and are classified as “available-for-sale securities” and recorded at fair market value. Unrealized gains and losses on investments are recorded as a component of accumulated other comprehensive income (loss). To determine whether any existing impairment is other-than-temporary and requires recognition of an impairment loss in the results of operations, the Company evaluates its marketable securities based on the nature of the investments and the Company’s intent and ability to hold the securities until the securities are no longer in an unrealized loss position.
Accounts receviable and allowance for doubtful accounts	Trade receivables are stated at the amount the Company expects to collect and generally do not bear interest. Credit limits are established by reviewing the financial history and stability of each customer. Where appropriate, the Company obtains credit rating reports and financial statements of the customer to establish or modify credit limits. On certain foreign sales, letters of credit are obtained. The collectability of trade receivable balances is regularly evaluated based on a combination of factors such as customer reputation and credit-worthiness, past transaction history with the customer, current economic and industry trends, among other factors. If it is determined or expected that a customer will be unable to fully meet its financial obligation, such as in the case of a bankruptcy filing or other material events impacting its business, a specific allowance for bad debt is recorded to reduce the related receivable to the amount expected to be recovered.
Accrued restructuring costs
Inventories	Inventories are principally valued at standard costs, which approximate the lower of cost or net realizable value on a first-in, first-out basis. Costs utilized for inventory valuation purposes include material, labor and manufacturing overhead
Shipped systems pending acceptance	Shipped systems pending acceptance relate to systems that have been ordered and shipped to the customer, but where revenue has been deferred in accordance with the Company’s revenue recognition policy. Shipped systems pending acceptance are recognized as cost of sales once all criteria for revenue recognition have been met and revenue is recorded. Shipped systems pending acceptance are valued at standard costs, which approximate the lower of cost (first-in, first-out) or net realizable value. Costs utilized in the valuation of shipped systems pending acceptance include material, labor and manufacturing overhead and exclude costs of installation.
Property, plant and equipment	Property, plant and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line basis over the estimated useful lives of the assets. Expenditures for maintenance, repairs and minor improvements are expensed as incurred. Major improvements and additions are capitalized. When assets are sold or retired in the normal course of business, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss is included as a component of operating expenses.
Long-lived asset impairment and amortization	Long-lived assets, principally property, plant and equipment and identifiable long-lived intangibles, are reviewed for impairment whenever events or circumstances indicate that the carrying amount of the assets may not be recoverable. The Company evaluates the recoverability of assets to be held and used by comparing the carrying amount of an asset or asset group to estimated future net undiscounted cash flows generated by the asset. If such assets are considered to be impaired, the impairment recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets. The Company’s purchased patents are amortized over their estimated useful lives, generally nine to seventeen years. Other purchased intangible assets with finite useful lives are carried at cost less accumulated amortization. Amortization expense is recognized on a straight-line basis over the estimated useful lives of the intangible assets, which range from one to ten years.
Goodwill impairment
Cost method investments
Fair value of financial instruments	The carrying amounts of financial instruments, including cash equivalents, accounts receivable, accounts payable, accrued liabilities and income taxes payable approximate fair value because of the nature of the underlying transactions and short-term maturities involved. Current and non-current marketable securities are recorded at fair value which is defined under FASB ASC Topic 820 “Fair Value Measurements and Disclosures” (ASC Topic 820).
Derivative financial instruments	The Company’s primary objective for holding derivative financial instruments is to manage currency risk. The Company’s accounting policies for these instruments are based on whether they meet the Company’s criteria for designation as hedging transactions, either as cash flow or fair value hedges. A hedge of the exposure to variability in the cash flows of an asset or a liability, or of a forecasted transaction, is referred to as a cash flow hedge. A hedge of the exposure to changes in fair value of an asset or a liability, or of an unrecognized firm commitment, is referred to as a fair value hedge. The criteria for designating a derivative as a hedge include the instrument’s effectiveness in risk reduction and, in most cases, a one-to-one matching of the derivative instrument to its underlying transaction. The Company enters into foreign currency exchange contracts as cashflow hedges to offset the earnings impact relating to the variability in exchange rates on certain short-term monetary assets and liabilities denominated in non-functional currencies. The Company does not designate these foreign currency contracts as hedges. The change in fair value of these derivative instruments not designated as hedging instruments is reported each period in other income (expense), net, in the Consolidated Statements of Operations.
Revenue recognition	The Company sells a significant portion of its products to a small number of large printed circuit board (PCB), semiconductor and microelectronics manufacturers. The Company's top ten customers for 2018 , 2017 and 2016 accounted for approximately 59% , 47% and 51% of total net sales, respectively. In 2018 , two customers, Career Technology (Mfg.). Co. Ltd. and Top Unique Trading Co. LTD., accounted for approximately 17% and 13% of net sales, respectively. In 2017 , two customers, Sumitomo Corporation and Zhen Ding Technologies, accounted for approximately 12% and 11% of net sales, respectively. One customer, Apple Inc. and its affiliates, accounted for approximately 15% of net sales in 2016 . No other customer individually accounted for more than 10% of total net sales in 2018 , 2017 or 2016 . The Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or the services have been rendered, the sales price is fixed or determinable and collection of the related receivable is reasonably assured. Title and risk of loss generally pass to the customer at the time of delivery of the product to a common carrier. Revenue is recognized upon such delivery, provided that fulfillment of acceptance criteria can be demonstrated prior to shipment. Where the acceptance criteria cannot be demonstrated prior to shipment, as in the case of substantially new products, revenue is deferred until acceptance has been received. For multiple element arrangements, the relative fair value of any undelivered elements is deferred until the elements are delivered and acceptance criteria, if any, are met. Revenues are recorded net of taxes collected which are required to be submitted to government authorities. Installation services are not essential to the functionality of the delivered equipment and installation revenue is deferred as a separate deliverable until installation is complete. Neither accrued installation costs nor the fair value of installation service revenue deferred has been material. Revenues associated with sales to customers under local contracts in Japan are generally recognized upon title transfer, which occurs upon customer acceptance. Revenues related to spare parts and consumable sales are generally recognized upon shipment. Revenues related to maintenance and service contracts are generally recognized ratably over the duration of the contracts.
Product warranty	The Company evaluates obligations related to product warranties quarterly. A standard warranty is provided on most of the Company's products over a specified period of time, generally 12 to 24 months, at no additional cost to its customers. Warranty charges are comprised of costs to service the warranty, including labor to repair the system and replacement parts for defective items, as well as other costs incidental to the repairs. Warranty charges are recorded net of any cost recoveries resulting from either successful repair of damaged parts or from warranties offered by the Company’s suppliers for defective components. Using historical data, the Company estimates average warranty cost per system or part type and records the provision for such charges as an element of cost of sales upon recognition of the related revenue. Additionally, the overall warranty accrual balance is separately analyzed using the remaining warranty periods outstanding on systems and items under warranty, and any resulting changes in estimates are recorded as an adjustment to cost of sales. If circumstances change, or if a significant change in warranty-related incidents occurs, the impact of the change in the warranty accrual could be material. Accrued product warranty is included on the Consolidated Balance Sheets as a component of accrued liabilities.
Research and development	Research and development costs, which include labor and related employee expenses, patent maintenance fees, project materials costs, development tool placement and installation costs, project subcontractors, depreciation of engineering equipment, building costs and other administration expenses, are generally expensed as incurred. Engineering materials that are expected to provide future value are included in inventories.
Comprehensive income (loss)	Comprehensive income (loss) includes net income (loss) and other comprehensive income (loss), which includes charges or credits to equity that are not the result of transactions with shareholders. Comprehensive income (loss) comprised primarily of cumulative foreign currency translation adjustments, benefit plan obligations and unrealized gains and losses on securities available for sale. The cumulative translation adjustment included in accumulated other comprehensive income (loss) at March 31, 2018 and April 1, 2017 was $0.6 million and $(1.2) million , respectively.
Earnings per share	Basic earnings per share (EPS) is computed by dividing income available to common stockholders by the weighted average number of shares outstanding during the period. Diluted EPS also considers common stock equivalents, such as stock options, stock-settled stock appreciation rights (SARs), employee stock purchase plan (ESPP) shares and restricted stock units, to the extent that they are not antidilutive.
Share-based compensation	The Company recognizes expense related to the fair value of SARs and ESPP using the Black-Scholes model to estimate the fair value of awards on the date of grant. The fair value of time-based and performance-based restricted stock units (RSUs) are measured on the grant date based on the market value of the Company's common stock. The market-based RSUs must achieve the total shareholder return (TSR) measures in order for the awards to vest, and the grant date fair value of the awards is calculated using a Monte Carlo simulation model. Except performance-based RSUs, the Company recognizes compensation expense for all share-based compensation awards, net of estimated forfeitures, on a straight-line basis over the requisite service period of the award. Expense for performance-based RSUs is recognized based on the probability of achievement of the performance criteria. The compensation cost for market-based RSUs is recognized on a straight-line basis over the related service period, even if the market condition is never satisfied.
Segment reporting	The Company complies with ASC Topic 280 Segment Reporting (ASC Topic 280). ASC Topic 280, which is based on a management approach to segment reporting, establishes requirements to report selected segment information quarterly and to report annually entity-wide disclosures about products, major customers and the geographies in which the entity holds material assets and reports revenue. An operating segment is defined as a component that engages in business activities whose operating results are reviewed by the chief operating decision maker and for which discrete financial information is available. Based on the provisions of ASC Topic 280, the Company has determined that it operates in a single segment. There is no difference between the accounting policies used for the segment compared to those used on a consolidated basis.
Employee benefit plans	The Company has an employee savings plan under the provisions of Section 401(k) of the Internal Revenue Code. During 2018 , 2017 and 2016 , contributions to the plan by the Company were $0.7 million, $0.8 million and $0.7 million, respectively. The Company has defined benefit retirement plans at certain of its foreign subsidiaries. The Company accounts for these plans based on the provisions of ASC Topic 715, Compensation-Retirement Benefits .

Other Assets Other Assets (Poli

Other Assets Other Assets (Policies)	12 Months Ended
	Mar. 31, 2018
Other Assets [Abstract]
Consignment Demo And Training Equipment [Policy Text Block]	onsignment, demo and training equipment are recorded at the lower of standard costs or estimated market values.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Hierarchy for Financial Assets Measured at Fair Value on Recurring Basis	Financial Assets Measured at Fair Value The Company’s fair value hierarchy for its financial assets measured at fair value on a recurring basis as of March 31, 2018 and April 1, 2017 was as follows (in thousands): March 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents: Money market securities $ 41,752 $ — $ — $ 41,752 U.S. treasury fund 2,500 — — 2,500 Commercial paper — 3,498 — 3,498 Corporate bonds — 1,999 — 1,999 Total cash equivalents $ 44,252 $ 5,497 $ — $ 49,749 Short term investments - available for sale: U.S. treasury fund $ 10,458 $ — $ — $ 10,458 Commercial paper — 25,913 — 25,913 Corporate bonds — 10,750 — 10,750 Total short-term investments - available for sale $ 10,458 $ 36,663 $ — $ 47,121 Forward purchase or sale contracts: Japanese Yen $ — $ (23 ) $ — $ (23 ) New Taiwan Dollar — 3 — 3 Korean Won — (12 ) — (12 ) Euro — 7 — 7 British Pound — 49 — 49 Chinese Renminbi — (29 ) — (29 ) Singapore Dollar — (1 ) — (1 ) Total forward contracts $ — $ (6 ) $ — $ (6 ) Deferred compensation plan assets:* Mutual funds and exchange traded funds $ 1,841 $ — $ — $ 1,841 Money market securities 207 — — 207 Total deferred compensation plan assets $ 2,048 $ — $ — $ 2,048 *These investments represent assets held in trust for ESI's deferred compensation plan April 1, 2017 Level 1 Level 2 Level 3 Total Cash equivalents: Money market securities $ 22,395 $ — $ — $ 22,395 Commercial paper — 4,945 — 4,945 Total cash equivalents $ 22,395 $ 4,945 $ — $ 27,340 Short term investments - available for sale: Commercial paper $ — $ 5,743 $ — $ 5,743 Total short-term investments - available for sale $ — $ 5,743 $ — $ 5,743 Forward purchase or sale contracts: Japanese Yen $ — $ 9 $ — $ 9 New Taiwan Dollar — 20 — 20 Korean Won — 39 — 39 Euro — (96 ) — (96 ) Chinese Renminbi — (5 ) — (5 ) Singapore Dollar — (1 ) — (1 ) Total forward contracts $ — $ (18 ) $ — $ (18 ) Deferred compensation plan assets:* Mutual funds and exchange traded funds $ 845 $ — $ — $ 845 Money market securities 2,213 — — 2,213 Total deferred compensation plan assets $ 3,058 $ — $ — $ 3,058 *These investments represent assets held in trust for ESI's deferred compensation plan
Investments	March 31, 2018 and April 1, 2017 were as follows (in thousands): Unrealized March 31, 2018 Cost Gain Loss Fair Value Available-for-sale securities (current): U.S. treasury fund $ 12,975 $ — $ (17 ) $ 12,958 Commercial paper 29,411 — — 29,411 Corporate bonds 12,768 — (19 ) 12,749 Total investments (current) $ 55,154 $ — $ (36 ) $ 55,118 Available-for-sale securities (non-current): Mutual funds, exchange traded funds and money market securities* $ 1,881 $ 167 $ — $ 2,048 Total investments (non-current) $ 1,881 $ 167 $ — $ 2,048 Unrealized April 1, 2017 Cost Gain Loss Fair Value Available-for-sale securities (current): Commercial paper $ 10,688 $ — $ — $ 10,688 Total investments (current) $ 10,688 $ — $ — $ 10,688 Available-for-sale securities (non-current): Mutual funds, exchange traded funds and money market securities* $ 2,974 $ 84 $ — $ 3,058 Total investments (non-current) $ 2,974 $ 84 $ — $ 3,058

Derivative Financial Instrume36

Derivative Financial Instruments (Tables)	12 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions	Bought (Sold) (In thousands) 2018 2017 Japanese Yen $ 5,456 $ 1,352 Euro 6,613 7,568 New Taiwan Dollar (1,546 ) (686 ) Korean Won (218 ) 32 British Pound (3,031 ) (1,992 ) Chinese Renminbi 2,665 995 Singapore Dollar 659 74 $ 10,598 $ 7,343

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Components of Inventories	The components of inventories at March 31, 2018 and April 1, 2017 were as follows: (In thousands) 2018 2017 Raw materials and purchased parts $ 52,591 $ 41,383 Work-in-process 18,634 13,829 Finished goods 16,461 3,730 $ 87,686 $ 58,942

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, plant and equipment as of March 31, 2018 and April 1, 2017 consisted of the following: (In thousands) Weighted Average 2018 2017 Land n/a $ 2,152 $ 2,152 Buildings and improvements 18 38,467 36,204 Machinery and equipment 5 41,889 59,099 Computer equipment and software 5 22,676 36,239 105,184 133,694 Less accumulated depreciation (83,159 ) (112,075 ) $ 22,025 $ 21,619

Acquired Intangible Assets (Tab

Acquired Intangible Assets (Tables)	12 Months Ended
	Mar. 31, 2018
Intangible Assets Disclosure [Abstract]
Schedule of Finite and Indefinite Lived Intangible Assets	Acquired intangible assets as of March 31, 2018 and April 1, 2017 consisted of the following: (In thousands, except years) Weighted 2018 2017 Developed technology 7.5 $ 18,646 $ 18,646 Customer relationships 5.3 3,914 3,914 Customer backlog 1.0 1,270 1,270 Trade name and trademarks 3.8 793 793 Fair value of below-market lease (non-current portion) 3.8 310 310 Change of control agreements and non-compete agreements 2.1 160 160 Patents 12.7 2,842 3,465 27,935 28,558 Less accumulated amortization (22,766 ) (21,994 ) $ 5,169 $ 6,564
Schedule of Components of Amortization Expense	Amortization expense for acquired intangible assets has been recorded in the Consolidated Statements of Operations as follows: (In thousands) 2018 2017 2016 Cost of sales $ 977 $ 1,133 $ 1,140 Selling, general and administration 208 209 36 Research, development and engineering 188 188 200 $ 1,373 $ 1,530 $ 1,376
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated amortization expense for acquired intangible assets in future years is as follows (in thousands): Year Amortization 2019 $ 1,427 2020 1,404 2021 1,245 2022 695 2023 298 Future years 100 $ 5,169

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Mar. 31, 2018
Disclosure Accrued Liabilities [Abstract]
Accrued Liabilities	Accrued liabilities (current) consisted of the following at March 31, 2018 and April 1, 2017 : (In thousands) 2018 2017 Payroll-related liabilities $ 15,879 $ 6,335 Restructuring and cost management amounts payable 429 4,996 Product warranty accrual 4,646 3,394 Purchase order commitments and receipts 2,978 2,522 Customer deposits 2,214 1,242 Professional fees payable 778 734 Current portion, long-term debt 421 434 Other current liabilities 7,188 2,529 $ 34,533 $ 22,186 Included in other liabilities above are accrued amounts for value-added taxes, income taxes, commissions payable to external representatives, freight and other similar items.

Product Warranty (Tables)

Product Warranty (Tables)	12 Months Ended
	Mar. 31, 2018
Product Warranties Disclosures [Abstract]
Reconciliation of the Change in Aggregate Accrual for Product Warranty	The following is a reconciliation of the changes in the aggregate product warranty accrual for 2018 , 2017 and 2016 : (In thousands) 2018 2017 2016 Product warranty accrual, beginning $ 5,474 $ 5,734 $ 3,342 Warranty charges incurred, net (11,247 ) (8,297 ) (7,781 ) Provision for warranty charges 15,993 8,037 10,173 Product warranty accrual, ending $ 10,220 $ 5,474 $ 5,734

Deferred Revenue (Tables)

Deferred Revenue (Tables)	12 Months Ended
	Mar. 31, 2018
Deferred Revenue Disclosure [Abstract]
Reconciliation of the Changes in Deferred Revenue	The following is a reconciliation of the changes in deferred revenue for 2018 , 2017 and 2016 : (In thousands) 2018 2017 2016 Deferred revenue, beginning $ 15,397 $ 7,685 $ 12,376 Revenue deferred 82,394 43,379 58,416 Revenue recognized (87,277 ) (35,667 ) (63,107 ) Deferred revenue, ending $ 10,514 $ 15,397 $ 7,685

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Aggregate commitments under operating leases	The aggregate minimum commitment obligation under operating leases beyond March 31, 2018 was as follows (in thousands): Year Operating Leases 2019 $ 2,504 2020 2,080 2021 1,513 2022 902 2023 199 Thereafter 585 $ 7,783

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense	Share-based compensation expense was included in the Company’s Consolidated Statements of Operations as follows: (In thousands) 2018 2017 2016 Cost of sales $ 277 $ 503 $ 445 Selling, general and administration 3,657 5,197 3,004 Research, development and engineering 679 737 783 Share-based compensation expense $ 4,613 $ 6,437 $ 4,232
Fair value assumptions of options and SARs granted	The Black-Scholes pricing model is utilized to determine the fair value of SARs granted and ESPP issued. No SARs were granted in 2018 and 2017 . The following weighted average assumptions were used in calculating the grant date fair value of SARs during the periods presented: 2018 2017 2016 Risk-free interest rate — % — % 1.94 % Expected lives 0.0 years 0.0 years 7.4 years Expected volatility — % — % 47 %
Fair value assumptions for ESPP	The following weighted average assumptions were used to estimate the fair value of ESPP shares issued in the periods presented: 2018 2017 2016 Risk-free interest rate 1.37 % 0.68 % 0.34 % Expected lives 0.6 years 1.1 years 1.1 years Expected volatility 55 % 45 % 35 %
Summary of awards	The total fair value of stock option and SAR awards granted and vested during the period, restricted stock unit awards granted and vested during the period, the intrinsic value of stock options and SARs exercised during the period and the total grant date fair value were: (In thousands, except per share data) 2018 2017 2016 Stock-Option and SAR Awards: Grant date fair value per share $ — $ — $ 2.89 Total fair value of options and SARs granted — — 1,350 Total fair value of options and SARs vested 755 820 336 Total intrinsic value of options and SARs exercised 6,641 17 1 Restricted Stock Unit Awards: Grant date fair value per share 10.59 6.71 5.52 Total fair value of awards granted 7,084 11,382 4,072 Total fair value of awards vested 4,945 3,693 4,324 Employee Stock Purchase Plan: Grant date fair value per share 2.14 1.40 1.22 Total grant date fair value 613 473 394
Stock option activity	Information with respect to stock option and SAR activity was as follows: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at March 28, 2015 2,229,046 $ 12.52 Granted 467,000 5.63 Exercised (2,500 ) 6.71 Expired or forfeited (537,946 ) 16.53 Outstanding at April 2, 2016 2,155,600 $ 10.03 5.35 $ 904 Granted — — Exercised (22,500 ) 6.23 Expired or forfeited (191,097 ) 19.20 Outstanding at April 1, 2017 1,942,003 $ 9.17 4.82 $ 634 Granted — — Exercised (1,280,478 ) 8.17 Expired or forfeited (548,000 ) 11.92 Outstanding at March 31, 2018 113,525 $ 7.26 4.17 $ 1,371 Vested and expected to vest at March 31, 2018 113,140 $ 7.26 4.16 $ 1,365 Exercisable at March 31, 2018 89,525 $ 7.64 3.42 $ 1,046
Restricted stock activity	Information with respect to time-based restricted stock unit awards activity was as follows: Shares Weighted Weighted Average Remaining Contractual Term (In years) Aggregate Outstanding at March 28, 2015 835,841 $ 8.90 Awarded 737,200 5.52 Vested (360,349 ) 11.75 Forfeited (130,888 ) 7.66 Outstanding at April 2, 2016 1,081,804 $ 6.77 1.93 $ 7,781 Awarded 1,051,445 6.63 Vested (483,239 ) 7.64 Forfeited (42,093 ) 6.67 Outstanding at April 1, 2017 1,607,917 $ 6.41 2.04 $ 11,168 Awarded 446,400 9.81 Vested (757,462 ) 6.53 Forfeited (396,830 ) 6.83 Outstanding at March 31, 2018 900,025 $ 7.82 2.39 $ 17,397

Quarterly Financial Informati45

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Mar. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly financial information	(In thousands, except per share data) 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter Year Ended March 31, 2018 Net sales Systems $ 62,093 $ 60,316 $ 99,418 $ 103,522 Services 10,591 10,651 11,422 9,871 Total net sales 72,684 70,967 110,840 113,393 Cost of sales: Systems 41,426 38,179 52,502 53,247 Services 4,838 6,256 5,182 5,424 Total cost of sales 46,264 44,435 57,684 58,671 Gross profit 26,420 26,532 53,156 54,722 Net income 2,902 4,260 33,973 75,088 Basic net income per share 0.09 0.13 0.99 2.19 Diluted net income per share 0.08 0.12 0.94 2.10 Year Ended April 1, 2017 Net sales Systems $ 38,200 $ 21,442 $ 25,427 $ 40,029 Service 9,468 8,216 8,352 9,889 Total net sales 47,668 29,658 33,779 49,918 Cost of sales: Systems 22,422 14,146 17,283 27,499 Service 4,438 4,532 5,048 4,189 Total cost of sales 26,860 18,678 22,331 31,688 Gross profit 20,808 10,980 11,448 18,230 Net loss (118 ) (9,675 ) (9,693 ) (17,923 ) Basic net loss per share — (0.30 ) (0.29 ) (0.54 ) Diluted net loss per share — (0.30 ) (0.29 ) (0.54 )

(Loss) Earnings Per Share (Tabl

(Loss) Earnings Per Share (Tables)	12 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Reconciliation of Weighted Average Shares Outstanding Used in Calculation of Basic and Diluted Earnings Per Share	The following was a reconciliation of weighted average shares outstanding used in the calculation of basic and diluted earnings (loss) per share for 2018 , 2017 and 2016 : (In thousands, except per share data) 2018 2017 2016 Net income (loss) $ 116,223 $ (37,409 ) $ (12,257 ) Weighted average shares used for basic earnings per share 33,967 32,551 31,411 Incremental diluted shares 1,604 — — Weighted average shares used for diluted earnings per share 35,571 32,551 31,411 Net income (loss) per share: Basic $ 3.42 $ (1.15 ) $ (0.39 ) Diluted $ 3.27 $ (1.15 ) $ (0.39 )

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Components of net deferred tax assets	Net deferred tax assets and liabilities at March 31, 2018 and April 1, 2017 consisted of the following:
Components of income tax expense and provision for income taxes	The components of income before income taxes and the (benefit from) provision for income taxes, all from continuing operations, were as follows: (In thousands) 2018 2017 2016 Income (loss) before income taxes: Domestic $ 61,539 $ (32,646 ) $ (13,385 ) Foreign 14,414 (4,786 ) 1,112 Total income (loss) before income taxes $ 75,953 $ (37,432 ) $ (12,273 ) Provision for (benefit from) income taxes: Current: U.S. federal and state $ (248 ) $ (379 ) $ 8 Foreign 2,614 557 916 Total current 2,366 178 924 Deferred: U.S. federal and state (42,329 ) — — Foreign (307 ) (201 ) (940 ) Total deferred (42,636 ) (201 ) (940 ) Total benefit from income taxes $ (40,270 ) $ (23 ) $ (16 )
Reconciliation of effective tax rate	A reconciliation of the Company’s effective tax rate to the United States federal statutory income tax rate was as follows: 2018 2017 2016 U.S. federal statutory income tax rate 31.5 % 35.0 % 35.0 % State income taxes, net of federal benefit 3.7 (0.3 ) (0.5 ) Tax credits (4.5 ) 4.2 17.1 Non-U.S. income taxed at different rates (3.3 ) (0.9 ) 14.3 Changes in unrecognized tax benefits 4.5 (0.3 ) (4.1 ) Change in valuation allowance (111.2 ) (25.0 ) (51.8 ) Stock compensation (3.3 ) (2.6 ) (10.2 ) Intangible write-off — (5.1 ) — Acquisitions — (5.9 ) — Change in Rate 22.5 — — Mandated Repatriation of Foreign Earnings 9.0 — — Other, net (1.9 ) 1.0 0.3 Effective tax rate (53.0 )% 0.1 % 0.1 %
Tax years subject to examination	As of March 31, 2018 , the following tax years remained subject to examination by the major tax jurisdictions indicated: Major Jurisdictions Open Tax Years Canada 2011 and forward China 2008 and forward France 2015 and forward Japan 2011 and forward Korea 2013 and forward Singapore 2012 and forward Taiwan 2013 and forward United Kingdom 2014 and forward United States 2004 and forward
Rollforward of unrecognized income tax benefits	A reconciliation of the beginning and ending amount of the consolidated liability for unrecognized income tax benefits for the years ended March 31, 2018 , April 1, 2017 and April 2, 2016 was as follows: (In thousands) 2018 2017 2016 Beginning unrecognized tax benefits balance $ 10,744 $ 10,385 $ 9,654 Gross increases for tax positions of prior years 2,909 62 731 Gross decreases for tax positions of prior years (397 ) (242 ) — Gross increases for tax positions for current year 1,060 539 — Ending unrecognized tax benefits balance $ 14,316 $ 10,744 $ 10,385

Product and Geographic Inform48

Product and Geographic Information (Tables)	12 Months Ended
	Mar. 31, 2018
Revenue from External Customer [Line Items]
Gross profit (loss) by segments	(In thousands) 2018 2017 2016 Printed Circuit Board $ 256,430 $ 88,771 $ 94,121 Component Test 32,790 22,381 19,901 Semiconductor 55,171 29,557 38,262 Industrial Machining 23,493 20,314 32,107 $ 367,884 $ 161,023 $ 184,391
Net sales by geographic area, based on location of end user	Net sales by geographic area, based on the location of the end user, were as follows: (In thousands) 2018 2017 2016 Asia $ 332,499 $ 134,394 $ 152,259 Americas 19,241 16,378 21,206 Europe 16,144 10,251 10,926 $ 367,884 $ 161,023 $ 184,391
Long-lived assets by geographic area	Long-lived assets; exclusive of investments, restricted cash and deferred taxes; by geographic area were as follows: (In thousands) 2018 2017 Americas $ 22,057 $ 32,234 Asia 13,811 8,111 Europe 5,591 5,648 $ 41,459 $ 45,993

Summary of Significant Accoun49

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Significant Accounting Policies [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 76,792	$ 56,642
Contributions to 401(k) during the period	700	800	$ 700
Restricted Cash	1,093	1,090
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 77,885	$ 57,732
Top ten customers | Net sales
Significant Accounting Policies [Line Items]
Customer concentration risk, percentage	59.00%	47.00%	51.00%
Individually Significant Customer1 [Member] | Net sales
Significant Accounting Policies [Line Items]
Customer concentration risk, percentage	17.00%
Individually Significant Customer2 [Member] | Net sales
Significant Accounting Policies [Line Items]
Customer concentration risk, percentage	13.00%
Individually Significant Customer3 [Member] | Net sales
Significant Accounting Policies [Line Items]
Customer concentration risk, percentage		12.00%
Individually Significant Customer4 [Member] [Domain] | Net sales
Significant Accounting Policies [Line Items]
Customer concentration risk, percentage		11.00%
Individually Significant Customer5 [Member] [Domain] | Net sales
Significant Accounting Policies [Line Items]
Customer concentration risk, percentage			15.00%
Minimum | Patents
Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	9 years
Minimum | Other intangible assets
Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	1 year
Maximum | Patents
Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	17 years
Maximum | Other intangible assets
Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	10 years

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy for Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Apr. 01, 2017
Available for sale Securities Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale Securities		$ 55,118	$ 10,688
Commercial Paper | Available for sale Securities Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale Securities		29,411	10,688
Corporate Bonds | Available for sale Securities Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale Securities		12,749
US Treasury Securities [Member] | Available for sale Securities Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale Securities		12,958
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Plan Assets	[1]	2,048
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Plan Assets	[1]	2,048
Fair Value, Measurements, Recurring | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		47,121	5,743
Fair Value, Measurements, Recurring | Short-term Investments [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		10,458	0
Fair Value, Measurements, Recurring | Short-term Investments [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		36,663	5,743
Fair Value, Measurements, Recurring | Short-term Investments [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets			0
Fair Value, Measurements, Recurring | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		3,058
Fair Value, Measurements, Recurring | Other Assets [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		3,058
Fair Value, Measurements, Recurring | Other Assets [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		0
Fair Value, Measurements, Recurring | Other Assets [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		0
Fair Value, Measurements, Recurring | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		49,749	27,340
Fair Value, Measurements, Recurring | Cash Equivalents [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		44,252	22,395
Fair Value, Measurements, Recurring | Cash Equivalents [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		5,497	4,945
Fair Value, Measurements, Recurring | Cash Equivalents [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets			0
Fair Value, Measurements, Recurring | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Plan Assets	[1]	207
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Plan Assets	[1]	207
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		2,213
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Other Assets [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		2,213
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Other Assets [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		0
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Other Assets [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		0
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		41,752	22,395
Fair Value, Measurements, Recurring | Money Market Funds [Member] | Cash Equivalents [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		41,752	22,395
Fair Value, Measurements, Recurring | Commercial Paper | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		25,913	5,743
Fair Value, Measurements, Recurring | Commercial Paper | Short-term Investments [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		25,913	5,743
Fair Value, Measurements, Recurring | Commercial Paper | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		3,498	4,945
Fair Value, Measurements, Recurring | Commercial Paper | Cash Equivalents [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		3,498	4,945
Fair Value, Measurements, Recurring | Corporate Bonds | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		10,750
Fair Value, Measurements, Recurring | Corporate Bonds | Short-term Investments [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		10,750
Fair Value, Measurements, Recurring | Corporate Bonds | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		1,999
Fair Value, Measurements, Recurring | Corporate Bonds | Cash Equivalents [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		1,999
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(6)	(18)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Japanese Yen
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets			9
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(23)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | New Taiwan Dollars
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		3	20
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Korean Won
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets			39
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(12)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Euro
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		7
Financial and Nonfinancial Liabilities, Fair Value Disclosure			(96)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | British Pound
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		49
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Chinese Renminbi
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(29)	(5)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Singapore Dollar
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(1)	(1)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(6)	(18)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2 | Japanese Yen
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets			9
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(23)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2 | New Taiwan Dollars
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		3	20
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2 | Korean Won
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets			39
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(12)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2 | Euro
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		7
Financial and Nonfinancial Liabilities, Fair Value Disclosure			(96)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2 | British Pound
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		49
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2 | Chinese Renminbi
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(1)	(5)
Fair Value, Measurements, Recurring | Forward purchase or (sale) contracts | Level 2 | Singapore Dollar
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Financial and Nonfinancial Liabilities, Fair Value Disclosure		(29)	(1)
Fair Value, Measurements, Recurring | US Treasury Securities [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		10,458
Fair Value, Measurements, Recurring | US Treasury Securities [Member] | Short-term Investments [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		10,458
Fair Value, Measurements, Recurring | US Treasury Securities [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		2,500
Fair Value, Measurements, Recurring | US Treasury Securities [Member] | Cash Equivalents [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets		2,500
Fair Value, Measurements, Recurring | Exchange Traded Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Plan Assets	[1]	1,841
Fair Value, Measurements, Recurring | Exchange Traded Funds [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Plan Assets	[1]	$ 1,841
Fair Value, Measurements, Recurring | Exchange Traded Funds [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		845
Fair Value, Measurements, Recurring | Exchange Traded Funds [Member] | Other Assets [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		845
Fair Value, Measurements, Recurring | Exchange Traded Funds [Member] | Other Assets [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		0
Fair Value, Measurements, Recurring | Exchange Traded Funds [Member] | Other Assets [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of financial assets	[2]		$ 0
[1]	*These investments represent assets held in trust for ESI's deferred compensation plan
[2]	*These investments represent assets held in trust for ESI's deferred compensation plan

Fair Value Measurements - Inves

Fair Value Measurements - Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Available for sale Securities Current
Schedule of Available-for-sale Securities
Available-for-sale Securities	$ 55,118	$ 10,688
Unrealized Gain	0	0
Unrealized Loss	(36)	0
Cost	55,154	10,688
Available for sale Securities Current | US Treasury Securities [Member]
Schedule of Available-for-sale Securities
Available-for-sale Securities	12,958
Unrealized Gain	0
Unrealized Loss	(17)
Cost	12,975
Available for sale Securities Current | Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale Securities	29,411	10,688
Unrealized Gain	0	0
Unrealized Loss	0	0
Cost	29,411	10,688
Available for sale Securities Current | Corporate Bonds
Schedule of Available-for-sale Securities
Available-for-sale Securities	12,749
Unrealized Gain	0
Unrealized Loss	(19)
Cost	12,768
Available for sale Securities Non Current
Schedule of Available-for-sale Securities
Available-for-sale Securities	2,048	3,058
Unrealized Gain	167	84
Unrealized Loss	0	0
Cost	1,881	2,974
Available for sale Securities Non Current | Exchange Traded Funds [Member]
Schedule of Available-for-sale Securities
Available-for-sale Securities	2,048
Unrealized Gain	167
Unrealized Loss	0
Cost	$ 1,881
Available for sale Securities Non Current | Municipal Bonds
Schedule of Available-for-sale Securities
Available-for-sale Securities		3,058
Unrealized Gain		84
Unrealized Loss		0
Cost		$ 2,974

Derivative Financial Instrume52

Derivative Financial Instruments (Details) - Forward exchange contract - USD ($) $ in Thousands	Mar. 31, 2018	Apr. 01, 2017
Long [Member]
Derivative [Line Items]
Notional amount of currencies purchased and sold	$ (10,598)	$ (7,343)
Long [Member] | Japanese Yen
Derivative [Line Items]
Notional amount of currencies purchased and sold	(5,456)	(1,352)
Long [Member] | Euro
Derivative [Line Items]
Notional amount of currencies purchased and sold	(6,613)	(7,568)
Long [Member] | Korean Won
Derivative [Line Items]
Notional amount of currencies purchased and sold		(32)
Long [Member] | Chinese Renminbi
Derivative [Line Items]
Notional amount of currencies purchased and sold	(2,665)
Long [Member] | Singapore Dollar
Derivative [Line Items]
Notional amount of currencies purchased and sold	(659)	(74)
Short [Member] | New Taiwan Dollars
Derivative [Line Items]
Notional amount of currencies purchased and sold	(1,546)	(686)
Short [Member] | Korean Won
Derivative [Line Items]
Notional amount of currencies purchased and sold	(218)
Short [Member] | British Pound
Derivative [Line Items]
Notional amount of currencies purchased and sold	$ (3,031)	(1,992)
Short [Member] | Chinese Renminbi
Derivative [Line Items]
Notional amount of currencies purchased and sold		$ (995)

Trade Receivables, net (Details

Trade Receivables, net (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Apr. 01, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Net, Current	$ 63,044	$ 40,494
Accounts Receivable, Net, Noncurrent	0	489
Accounts Receivable, Net	$ 63,044	$ 40,983

Inventories - Components of Inv

Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Inventory [Line Items]
Impairment of Inventory due to Restructuring	$ 8,200	$ 1,700	$ 1,400
Inventory, Raw Materials, Net of Reserves	52,591	41,383
Inventory, Work in Process, Net of Reserves	18,634	13,829
Inventory Write-off due to Storm Damage	900
Inventory, Finished Goods, Net of Reserves	16,461	3,730
Inventories	$ 87,686	$ 58,942

Property, Plant and Equipment55

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 105,184	$ 133,694
Less accumulated depreciation	(83,159)	(112,075)
Property, plant and equipment, net	22,025	21,619
Depreciation and amortization	$ 5,900	6,900	$ 6,800
Document Period End Date	Mar. 31, 2018
Restructuring and Related Cost, Accelerated Depreciation	$ 1,700
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,152	2,152
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 38,467	36,204
Estimated useful lives	18 years
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 41,889	59,099
Estimated useful lives	5 years
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 22,676	$ 36,239
Estimated useful lives	5 years

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Goodwill [Abstract]
Goodwill Disclosure Text Block		Company had approximately $2.6 million and $3.0 million of goodwill as of March 31, 2018 and April 1, 2017 , respectively. The entire balance was associated with the 2017 acquisition of Visicon (See Note 26: Business Acquisitions for further discussion). Purchase accounting was not finalized for the Visicon acquisition as of April 1, 2017. During 2018, purchase accounting was completed and goodwill was adjusted down by $401 thousand . Changes in these balances are shown below: (In thousands) 2018 2017 Goodwill, beginning $ 3,027 $ 7,445 Purchase accounting adjustment - Visicon acquisition (401 ) — Recognized goodwill - Visicon acquisition (provisional) — 3,027 Impaired goodwill - Topwin reporting unit — (7,445 ) Goodwill, ending $ 2,626 $ 3,027 The Company tests goodwill for impairment annually or more frequently if an event occurs or circumstances would indicate that it is more likely than not the fair value of the reporting unit is less than the carrying value. The date of the annual test of goodwill is the first day of the fourth quarter. Accordingly, the Company performed a quantitative test for impairment of the recorded goodwill as of December 31, 2018 and January 1, 2017 for 2018 and 2017 , respectively. As a result of the 2017 test, the estimated fair value of the reporting unit associated with the Topwin acquisition was determined to be less than the carrying value of the reporting unit, indicating a full impairment and hence the Company recognized an impairment loss of $7.4 million . The 2017 loss from impairment of goodwill was recorded as a component of operating expenses in a separate line on the Consolidated Statements of Operations. The fair value of the goodwill was determined using generally accepted valuation approaches. These approaches included a discounted cash flow model, a guideline transaction approach, and a guideline public company market multiples approach, each weighted according to the relevance of each approach. In supporting these valuations, management used assumptions based on the best information available. The 2018 test did not indicate impairment. The primary assumption used in determining that the single reporting unit was not impaired, was the increase in the Company's stock price which provided significant headroom before an impairment would be indicated.
Goodwill [Line Items]
Goodwill	$ 3,027	$ 2,626	$ 3,027	$ 7,445
Goodwill, Purchase Accounting Adjustments		(401)	0
Goodwill, Acquired During Period		0	3,027
Goodwill, Impairment Loss	$ (7,400)	$ 0	$ (7,445)	$ 0

Acquired Intangible Assets - Co

Acquired Intangible Assets - Components of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 27,935	$ 28,558
Less accumulated amortization	(22,766)	(21,994)
Total acquired intangible assets	5,169	6,564
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 18,646	18,646
Weighted average useful life	7 years 5 months 16 days
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 3,914	3,914
Weighted average useful life	5 years 3 months 5 days
Customer backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 1,270	1,270
Weighted average useful life	1 year
Trade name and trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 793	793
Weighted average useful life	3 years 9 months 30 days
Fair value of below-market lease
Acquired Finite-Lived Intangible Assets [Line Items]
Below Market Lease, Gross	$ 310	310
Weighted average useful life	3 years 9 months 18 days
Change of control agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 160	160
Weighted average useful life	2 years 1 month 15 days
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 2,842	$ 3,465
Weighted average useful life	12 years 8 months 1 day

Acquired Intangible Assets - 58

Acquired Intangible Assets - Components of Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangibles	$ 1,373	$ 1,530	$ 1,376
Cost of Sales
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangibles	977	1,133	1,140
Selling, service and administration
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangibles	208	209	36
Research, development and engineering
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangibles	$ 188	$ 188	$ 200

Acquired Intangible Assets - Fu

Acquired Intangible Assets - Future Amortization Expense (Details) $ in Thousands	Mar. 31, 2018USD ($)
Intangible Assets Disclosure [Abstract]
2,015	$ 1,427
2,016	1,404
2,017	1,245
2,018	695
2,019	298
Future years	100
Total	$ 5,169

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Disclosure Other Assets [Abstract]
Schedule of Other Assets, Noncurrent [Table Text Block]	Other assets consisted of the following as of March 31, 2018 and April 1, 2017 : (In thousands) 2018 2017 Demo and leased equipment, net $ 6,746 $ 11,011 Long term deposits 3,232 2,872 Long term restricted cash 1,093 1,090 Other non-current assets 3,709 3,958 $ 14,780 $ 18,931
Other Assets Noncurrent Disclosure [Text Block]	er assets consisted of the following as of March 31, 2018 and April 1, 2017 : (In thousands) 2018 2017 Demo and leased equipment, net $ 6,746 $ 11,011 Long term deposits 3,232 2,872 Long term restricted cash 1,093 1,090 Other non-current assets 3,709 3,958 $ 14,780 $ 18,931 Depreciation expense for demo equipment totaled $1.8 million in 2018 , $0.4 million in 2017 and $0.5 million 2016 . Included in Other non-current assets are long-term investments, vendor prepayments and other similar items.
Consignment and demo equipment, net	$ 6,746	$ 11,011
Long term deposits	3,232	2,872
Restricted Cash and Cash Equivalents, Noncurrent	1,093	1,090
Other	3,709	3,958
Other assets	14,780	18,931
Schedule of Cost-method Investments [Line Items]
Demo equipment depreciation expense	1,800	400	$ 500
Accounts Receivable, Net, Noncurrent	$ 0	$ 489

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Apr. 01, 2017
Disclosure Accrued Liabilities [Abstract]
Employee-related Liabilities, Current	$ 15,879	$ 6,335
Restructuring Reserve	429	4,996
Product warranty accrual	4,646	3,394
Purchase order commitments and receipts	2,978	2,522
Customer deposits	2,214	1,242
Professional fees payable	778	734
Freight accrual	421	434
Other	7,188	2,529
Accrued liabilities	$ 34,533	$ 22,186

Product Warranty (Details)

Product Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Product Warranties Disclosures [Abstract]
Product Warranty Accrual, Noncurrent	$ 5,600
Standard and Extended Product Warranty Accrual Beginning	5,474	$ 5,734	$ 3,342
Standard and Extended Product Warranty Accrual, Decrease for Payments	11,247	8,297	7,781
Standard and Extended Product Warranty Accrual, Increase for Warranties Issued	15,993	8,037	10,173
Standard and Extended Product Warranty Accrual Ending	$ 10,220	$ 5,474	$ 5,734

Deferred Revenue (Details)

Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Deferred Revenue Disclosure [Abstract]
Deferred Revenue, Noncurrent	$ 700	$ 700	$ 1,300
Deferred revenue, beginning	15,397	7,685	12,376
Revenue deferred	82,394	43,379	58,416
Revenue recognized	(87,277)	(35,667)	(63,107)
Deferred revenue, ending	$ 10,514	$ 15,397	$ 7,685

Debt (Details)

Debt (Details) - USD ($) $ in Thousands, number in Millions	120 Months Ended
	Jan. 01, 2027	Mar. 31, 2018	Apr. 01, 2017	Jan. 09, 2017
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months		$ 455
Long-term Debt, Excluding Current Maturities		12,766	$ 13,489
Long-term Debt, Maturities, Repayments of Principal in Year Two		475
Long-term Debt, Maturities, Repayments of Principal in Year Three		500
Long-term Debt, Maturities, Repayments of Principal in Year Four		524
Long-term Debt, Maturities, Repayments of Principal in Year Five		550
Mortgages [Member] | FacilityMorgageAgreementJan92017Member [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross				$ 14,000
Debt Instrument, Interest Rate, Stated Percentage				0.00%
Long-term Debt		13,187	13,923
Long-term Debt, Current Maturities		(421)	(434)
Debt Issuance Costs, Net		302	337
Long-term Debt, Excluding Current Maturities		$ 12,766	$ 13,489
Scenario, Forecast [Member] | Mortgages [Member] | FacilityMorgageAgreementJan92017Member [Member]
Debt Instrument [Line Items]
Debt Instrument, Term	20 years
Debt Instrument, Maturity Date	Jan. 1, 2027

Revolving Credit Facility (Deta

Revolving Credit Facility (Details) - Loan and Security Agreement (Loan Agreement) [Member] - Silicon Valley Bank (SVB) [Member] $ in Millions	Mar. 20, 2015USD ($)
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 30
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 15

Commitments and Contingencies66

Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Commitments and Contingencies Disclosure [Abstract]
2,015	$ 2,504
2,016	2,080
2,017	1,513
2,018	902
2,019	199
Thereafter	585
Total lease commitments	7,783
Rental expense	2,400	$ 2,600	$ 2,500
Purchase Obligation	84,300
purchase obligation Long-term	$ 7,900

Shareholders' Equity - Share Re

Shareholders' Equity - Share Repurchase Program (Details) $ in Millions	Dec. 09, 2011USD ($)
Stockholders' Equity Note [Abstract]
Share repurchase authorization amount	$ 20

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016	Mar. 28, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	$ 266,358	$ 144,531	$ 170,031	$ 177,321
Other Comprehensive Income (Loss), before Reclassifications, before Tax	1,339	(145)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Other Comprehensive Income (Loss), Tax	422	(74)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	1,832	(348)	(922)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	(61)	135	(4)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	(10)	(6)	3
Other Comprehensive Income (Loss), Net of Tax	1,761	(219)	(923)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	590	(1,242)	(894)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	1,493	(348)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Other Comprehensive Income (Loss), Tax	339	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	1,832	(348)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(16)	45	(90)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(119)	209
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Other Comprehensive Income (Loss), Tax	58	(74)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	(61)	135
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(27)	(17)	(11)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(35)	(6)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Other Comprehensive Income (Loss), Tax	25	0
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	(10)	(6)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	547	(1,214)	(995)	$ (72)
Other Comprehensive Income (Loss), Net of Tax	$ 1,761	$ (219)	$ (923)

Share-Based Compensation - Expe

Share-Based Compensation - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	$ 4,613	$ 6,437	$ 4,232
Cost of Sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	277	503	445
Selling, General and Administrative Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	3,657	5,197	3,004
Research and Development Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total share-based compensation expense	$ 679	$ 737	$ 783

Share-Based Compensation - Valu

Share-Based Compensation - Valuation Assumptions (Details)	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
2004 plan | Options and SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.00%	0.00%	1.94%
Expected lives	0 years	0 years	7 years 5 months 8 days
Expected volatility	0.00%	0.00%	47.00%
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.37%	0.68%	0.34%
Expected lives	6 months 25 days	1 year 1 month 10 days	1 year 22 days
Expected volatility	55.00%	45.00%	35.00%

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Options and SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share	$ 0	$ 0	$ 2.89
Total grant date fair value	$ 0	$ 0	$ 1,350
Total fair value of awards vested	755	820	336
Total intrinsic value	$ 6,641	$ 17	$ 1
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share	$ 10.59	$ 6.71	$ 5.52
Total grant date fair value	$ 7,084	$ 11,382	$ 4,072
Total fair value of awards vested	$ 4,945	$ 3,693	$ 4,324
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value per share	$ 2.14	$ 1.40	$ 1.22
Total grant date fair value	$ 613	$ 473	$ 394

Share-Based Compensation - Shar

Share-Based Compensation - Share Based Payment Award Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016	Mar. 28, 2015
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	593,265	643,565	400,987	593,704
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 8.76	$ 6.85	$ 6.93	$ 7.88
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	222,400	643,565	0
Grant date fair value per share	$ 12.17	$ 6.85	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	0	0	(5,592)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 0	$ 0	$ 14.64
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(272,700)	(400,987)	(187,125)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 7.27	$ 6.93	$ 10.84
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	1 year 9 months 11 days	2 years 5 months 5 days	1 year
Awards Other Than Options Aggregate Intrinsic Value	$ 11,468	$ 4,409	$ 2,928
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	900,025	1,607,917	1,081,804	835,841
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 7.82	$ 6.41	$ 6.77	$ 8.90
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	446,400	1,051,445	737,200
Grant date fair value per share	$ 9.81	$ 6.63	$ 5.52
SharebasedcompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsTRSUgrantsinPeriodWeightedAverageGrantDateFairvalue	$ 6.53	$ 7.64	$ 11.75
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(757,462)	(483,239)	(360,349)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 10.59	$ 6.71	$ 5.52
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(396,830)	(42,093)	(130,888)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 6.83	$ 6.67	$ 7.66
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	2 years 4 months 20 days	2 years 14 days	1 year 11 months 5 days
Awards Other Than Options Aggregate Intrinsic Value	$ 17,397	$ 11,168	$ 7,781
Options and SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance (shares), beginning of period	1,942,003	2,155,600	2,229,046
Weighted average exercise price, beginning of period	$ 9.17	$ 10.03	$ 12.52
Granted (shares)	0	0	467,000
Granted, Weighted Average Exercise Price	$ 0	$ 0	$ 5.63
Exercised (shares)	(1,280,478)	(22,500)	(2,500)
Exercised, Weighted Average Exercise Price	$ 8.17	$ 6.23	$ 6.71
Expired or forfeited (shares)	(548,000)	(191,097)	(537,946)
Expired or forfeited, Weighted Average Exercise Price	$ 11.92	$ 19.20	$ 16.53
Balance (shares) , end of period	113,525	1,942,003	2,155,600
Weighted average exercise price, end of period	$ 7.26	$ 9.17	$ 10.03
Vested and expected to vest (shares)	113,140
Vested and expected to vest, Weighted Average Exercise Price	$ 7.26
Options exercisable (shares)	89,525
Options exercisable, Weighted Average Exercise Price	$ 7.64
Options outstanding, weighted average remaining contractual term	4 years 2 months 1 day	4 years 9 months 25 days	5 years 4 months 6 days
Options vested and expected to vest, weighted average remaining contractual term	4 years 1 month 28 days
Options exercisable, weighted average remaining contractual term	3 years 5 months 1 day
Options outstanding, aggregate intrinsic value	$ 1,371	$ 634	$ 904
Options vested and expected to vest, aggregate intrinsic value	1,365
Options exercisable, aggregate intrinsic value	$ 1,046

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total amount of cash received from stock plan awards	$ (0.7)
Proceeds from Stock Plans		$ 0.5	$ 0.7
Total unrecognized share-based compensation, net of estimated forfeitures, expected recognition period	2 years 21 days
Shares reserved for issuance under existing plans	6,767,223
Shares available for grant	5,160,408
Options and SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	0	0	467,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized share-based compensation, net of estimated forfeitures	$ 7.4
2004 plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance under existing plans	1,606,815
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	5,400,000
Maximum contribution rate by employees	15.00%
Percentage of fair market value of common stock	85.00%
Length of offering period	6 months
Shares available for grant	999,091

Quarterly Financial Informati74

Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended					15 Months Ended
	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Mar. 31, 2018		Apr. 01, 2017		Apr. 02, 2016	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Release of Tax Valuation Allowance and other adjustments									$ (41,200)
Sales Revenue, Goods, Net	$ 103,522	$ 99,418	$ 60,316	$ 62,093	$ 40,029	$ 25,427	$ 21,442	$ 38,200	325,349		$ 125,098		$ 142,957
Sales Revenue, Services, Net	9,871	11,422	10,651	10,591	9,889	8,352	8,216	9,468	42,535		35,925		41,434
Net sales	113,393	110,840	70,967	72,684	49,918	33,779	29,658	47,668	367,884		161,023		184,391
Cost of Goods Sold	53,247	52,502	38,179	41,426	27,499	17,283	14,146	22,422	185,354		81,350		89,169
Cost of Services	5,424	5,182	6,256	4,838	4,189	5,048	4,532	4,438	21,700		18,207		22,519
Cost of Goods and Services Sold	58,671	57,684	44,435	46,264	31,688	22,331	18,678	26,860	207,054		99,557		111,688
Gross Profit	54,722	53,156	26,532	26,420	18,230	11,448	10,980	20,808	160,830		61,466		72,703
Net income (loss)	$ 75,088	$ 33,973	$ 4,260	$ 2,902	$ (17,923)	$ (9,693)	$ (9,675)	$ (118)	$ 116,223		$ (37,409)		$ (12,257)
Basic net (loss) income per share	$ 2.19	$ 0.99	$ 0.13	$ 0.09	$ (0.54)	$ (0.29)	$ (0.30)	$ 0	$ 3.42		$ (1.15)		$ (0.39)
Diluted net (loss) income per share	$ 2.10	$ 0.94	$ 0.12	$ 0.08	$ (0.54)	$ (0.29)	$ (0.30)	$ 0	$ 3.27		$ (1.15)		$ (0.39)
Other Quarterly Information [Abstract]
Impairment of Intangible Assets, Finite-lived					$ 2,300				$ 0		$ 2,349		$ 0
Restructuring Costs					6,600
Goodwill, Impairment Loss					7,400				0		7,445		0
Business Combination, Integration Related Costs									0		366		194
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property									(197)		(1,323)		(862)
Inventory Write-down					$ 1,700				8,248		2,440		0
Restructuring costs									3,935		6,935		$ 2,824
Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost									17,074		7,587			$ 24,660
Current Asset Impairments [Member] | Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost									$ 13,278	[1]	$ 1,669	[1]		$ 14,947	[2]
[1]	(1) Asset and facilities costs include inventory charges recorded in cost of sales.
[2]	(1) Current asset impairments include inventory charges recorded in cost of sales.

(Loss) Earnings Per Share - Rec

(Loss) Earnings Per Share - Reconciliation of Weighted Average Shares Outstanding Used in Calculation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ 75,088	$ 33,973	$ 4,260	$ 2,902	$ (17,923)	$ (9,693)	$ (9,675)	$ (118)	$ 116,223	$ (37,409)	$ (12,257)
Weighted average number of shares - basic									33,967	32,551	31,411
Weighted Average Number Diluted Shares Outstanding Adjustment									1,604	0	0
Weighted average shares used for diluted earnings per share									35,571	32,551	31,411
Net (loss) income per share - basic	$ 2.19	$ 0.99	$ 0.13	$ 0.09	$ (0.54)	$ (0.29)	$ (0.30)	$ 0	$ 3.42	$ (1.15)	$ (0.39)
Net (loss) income per share - diluted	$ 2.10	$ 0.94	$ 0.12	$ 0.08	$ (0.54)	$ (0.29)	$ (0.30)	$ 0	$ 3.27	$ (1.15)	$ (0.39)

(Loss) Earnings Per Share - Add

(Loss) Earnings Per Share - Additional Information (Details) - shares shares in Millions	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share
Number of shares that are not included in the calculation of diluted net earnings per share	0.3	2	2.3

Income Taxes - Components of Ne

Income Taxes - Components of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Non-current
Deferred tax asset, inventory and warranty, non-current	$ 7,904	$ 11,246
Deferred Tax Assets Receivables and other non-current assets	(49)	(274)
Deferred compensation	5,130	7,574
Non-current deferred tax liabilities, Intangible assets and investments	(272)	(382)
Accrued liabilities	2,322	3,006
Non-current deferred income taxes, net	821	3,478
Property, plant and equipment	3,142	5,029
Other comprehensive income	3	456
Tax loss and credit carryforwards	43,201	73,805
Deferred Tax Assets, Other		259
Deferred Tax Liabilities, Other	(185)
Total non-current deferred tax asset	62,017	104,197
Valuation allowance, non-current	(18,499)	(103,315)
Net deferred tax assets	43,518	$ 882
Increase in valuation allowance	$ 84,800

Income Taxes - Operating Losses

Income Taxes - Operating Losses and Tax Credits (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Apr. 01, 2017
Income Tax Disclosure [Abstract]
Federal net operating losses	$ 5,071	$ 35,566
Federal net operating losses	1,868	3,679
Foreign operating losses and tax credits	17,826	12,504
Federal research credits	24,127	22,590
State research credits	5,438	4,409
Federal minimum tax credit	0	935
Federal capital losses	3,039	5,015
Net operating loss carryforward, net of tax and tax credits	$ 57,369	$ 84,698

Income Taxes - Components of In

Income Taxes - Components of Income Before Income Taxes and Provision for Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
(Loss) income before income taxes:
Domestic	$ 61,539	$ (32,646)	$ (13,385)
Foreign	14,414	(4,786)	1,112
Income (loss) before income taxes	75,953	(37,432)	(12,273)
Current:
U.S. federal and state	(248)	(379)	8
Foreign	2,614	557	916
Current (benefit from) provision for income taxes	2,366	178	924
Deferred:
U.S. federal and state	(42,329)	0	0
Foreign	(307)	(201)	(940)
Deferred provision for (benefit from) income taxes	(42,636)	(201)	(940)
Total provision for (benefit from) income taxes	(40,270)	$ (23)	$ (16)
Tax benefit derived from stock-based compensation	$ 0

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Tax Rate (Details)	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	31.50%	35.00%	35.00%
State income taxes, net of federal benefit	3.70%	(0.30%)	(0.50%)
Tax credits		4.20%	17.10%
Effective Income Tax Rate Reconciliation Tax Credits Rate Reduction	(4.50%)
Non-U.S. income taxed at different rates	(3.30%)	(0.90%)	14.30%
Changes in unrecognized tax benefits	4.50%	(0.30%)	(4.10%)
Change in valuation allowance	(111.20%)	(25.00%)	(51.80%)
Stock compensation	(3.30%)	(2.60%)	(10.20%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount	0.00%	5.10%	0.00%
Effective Income Tax Rate Reconciliation, Acquiitions, Percent	0.00%	(5.90%)	0.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	22.50%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Percent	9.00%	0.00%	0.00%
Other, net	(1.90%)	1.00%	0.30%
Effective tax rate	(53.00%)	0.10%	0.10%

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Income Tax Disclosure [Abstract]
Effective income tax rate reconciliation, unrecognized tax benefits	$ 100	$ 0
Beginning unrecognized tax benefits balance	10,744	10,385	$ 9,654
Gross increases for tax positions of prior years	2,909	62	731
Gross decreases for tax positions of prior years	(397)	(242)	0
Gorss increases for tax positions for current year	1,060	539	0
Ending unrecognized tax benefits balance	$ 14,316	$ 10,744	$ 10,385

Income Taxes Income Taxes Text

Income Taxes Income Taxes Text (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Income Tax Contingency [Line Items]
U.S. federal and state	$ (42,329)	$ 0	$ 0
Deferred Tax Assets, Valuation Allowance, Noncurrent	18,499	$ 103,315
Change in Valuation Allowance due to utilization of net operating losses	24,900
Change in Valuation Allowance due to changes in Tax Rates	$ 17,600

Restructuring and Cost Manage83

Restructuring and Cost Management Plans - Restructuring Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended			15 Months Ended	120 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016	Mar. 31, 2018	Jan. 01, 2027	Jan. 09, 2017	Mar. 28, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 429	$ 4,996		$ 429
Restructuring costs	3,935	6,935	$ 2,824
Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	139	4,135	0	139
Restructuring and Related Cost, Expected Cost	24,660			24,660
Cash Payments for Restructuring	8,505	407
Restructuring and Related Cost, Incurred Cost	(17,074)	(7,587)		(24,660)
Chelmsford [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	290	861	757	$ 290			$ 1,997
Cash Payments for Restructuring	980	297	4,064
Restructuring and Related Cost, Incurred Cost	$ (409)	$ (401)	$ (2,824)
Mortgages [Member] | FacilityMorgageAgreementJan92017Member [Member]
Restructuring Cost and Reserve [Line Items]
Long-term Debt, Gross						$ 14,000
Scenario, Forecast [Member] | Mortgages [Member] | FacilityMorgageAgreementJan92017Member [Member]
Restructuring Cost and Reserve [Line Items]
Debt Instrument, Term					20 years

Restructuring and Cost Manage84

Restructuring and Cost Management Plans Q4 FY17 Plan Accrual Reconciliation (Details) - USD ($) $ in Thousands		12 Months Ended				15 Months Ended
		Mar. 31, 2018		Apr. 01, 2017		Mar. 31, 2018		Apr. 02, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		$ 429		$ 4,996		$ 429
Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		139		4,135		139		$ 0
Restructuring and Related Cost, Incurred Cost		(17,074)		(7,587)		(24,660)
Cash Payments for Restructuring		(8,505)		(407)
Non-cash items		(12,565)		(3,045)
Employee Severance [Member] | Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		139		3,247		139		0
Restructuring and Related Cost, Incurred Cost		(1,337)		(3,588)		(4,925)
Cash Payments for Restructuring		(4,445)		(341)
Non-cash items		0		0
Site Closures [Member] | Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		0		888		0		0
Restructuring and Related Cost, Incurred Cost		(627)		(888)		(1,516)
Cash Payments for Restructuring		(1,515)		0
Non-cash items		0		0
Current Asset Impairments [Member] | Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	[1]	0		0		0		0
Restructuring and Related Cost, Incurred Cost		(13,278)	[1]	(1,669)	[1]	(14,947)	[2]
Cash Payments for Restructuring	[1]	(2,402)		0
Non-cash items	[1]	(10,876)		(1,669)
Non-Current Asset Impairment [Member] | Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		0		0		0		0
Restructuring and Related Cost, Incurred Cost		(1,657)		(1,376)		(3,033)
Cash Payments for Restructuring				0
Cash Receipts For Restructuring		32
Non-cash items		(1,689)		(1,376)
Other Restructuring [Member] | Q4 FY17 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		0		0		0		$ 0
Restructuring and Related Cost, Incurred Cost		(175)		(66)		$ (239)
Cash Payments for Restructuring		(175)		(66)
Non-cash items		$ 0		$ 0
[1]	(1) Asset and facilities costs include inventory charges recorded in cost of sales.
[2]	(1) Current asset impairments include inventory charges recorded in cost of sales.

Restructuring and Cost Manage85

Restructuring and Cost Management Plans Q4 FY17 Restructuring Plan Expected Costs (Details) - Q4 FY17 Restructuring Plan [Member] - USD ($) $ in Thousands		12 Months Ended				15 Months Ended
		Mar. 31, 2018		Apr. 01, 2017		Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		$ 24,660				$ 24,660
Restructuring and Related Cost, Incurred Cost		(17,074)		$ (7,587)		(24,660)
Restructuring and Related Cost, Expected Cost Remaining		0				0
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		4,925				4,925
Restructuring and Related Cost, Incurred Cost		(1,337)		(3,588)		(4,925)
Restructuring and Related Cost, Expected Cost Remaining		0				0
Site Closures [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		1,516				1,516
Restructuring and Related Cost, Incurred Cost		(627)		(888)		(1,516)
Restructuring and Related Cost, Expected Cost Remaining		0				0
Current Asset Impairments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	[1]	14,947				14,947
Restructuring and Related Cost, Incurred Cost		(13,278)	[2]	(1,669)	[2]	(14,947)	[1]
Restructuring and Related Cost, Expected Cost Remaining	[1]	0				0
Non-Current Asset Impairment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		3,033				3,033
Restructuring and Related Cost, Incurred Cost		(1,657)		(1,376)		(3,033)
Restructuring and Related Cost, Expected Cost Remaining		0				0
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		239				239
Restructuring and Related Cost, Incurred Cost		(175)		$ (66)		(239)
Restructuring and Related Cost, Expected Cost Remaining		$ 0				$ 0
[1]	(1) Current asset impairments include inventory charges recorded in cost of sales.
[2]	(1) Asset and facilities costs include inventory charges recorded in cost of sales.

Restructuring and Cost Manage86

Restructuring and Cost Management Plans Chelmsford Restructuring Plan Accrual (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016	Mar. 28, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 429	$ 4,996
Chelmsford [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	290	861	$ 757	$ 1,997
Cash Payments for Restructuring	(980)	(297)	(4,064)
Restructuring and Related Cost, Incurred Cost	$ 409	$ 401	$ 2,824

Product and Geographic Inform87

Product and Geographic Information - Net Sales & Gross Profit by Product Category (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Product Category Reporting Information [Line Items]
Gross Profit	$ 54,722	$ 53,156	$ 26,532	$ 26,420	$ 18,230	$ 11,448	$ 10,980	$ 20,808	$ 160,830	$ 61,466	$ 72,703
Revenue, Net	$ 113,393	$ 110,840	$ 70,967	$ 72,684	$ 49,918	$ 33,779	$ 29,658	$ 47,668	367,884	161,023	184,391
Printed Circuit Board [Member]
Product Category Reporting Information [Line Items]
Revenue, Net									256,430	88,771	94,121
Component Test [Member]
Product Category Reporting Information [Line Items]
Revenue, Net									32,790	22,381	19,901
Semiconductor [Member]
Product Category Reporting Information [Line Items]
Revenue, Net									55,171	29,557	38,262
Industrial Machining [Member]
Product Category Reporting Information [Line Items]
Revenue, Net									$ 23,493	$ 20,314	$ 32,107

Product and Geographic Inform88

Product and Geographic Information - Net Sales by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net	$ 113,393	$ 110,840	$ 70,967	$ 72,684	$ 49,918	$ 33,779	$ 29,658	$ 47,668	$ 367,884	$ 161,023	$ 184,391
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net									332,499	134,394	152,259
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net									19,241	16,378	21,206
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, Net									$ 16,144	$ 10,251	$ 10,926

Product and Geographic Inform89

Product and Geographic Information - Long-Lived Assets By Geographic Area (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Apr. 01, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 41,459	$ 45,993
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	22,057	32,234
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	13,811	8,111
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 5,591	$ 5,648

Product and Geographic Inform90

Product and Geographic Information Net sales by market (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Revenue from External Customer [Line Items]
Revenue, Net	$ 113,393	$ 110,840	$ 70,967	$ 72,684	$ 49,918	$ 33,779	$ 29,658	$ 47,668	$ 367,884	$ 161,023	$ 184,391
Printed Circuit Board [Member]
Revenue from External Customer [Line Items]
Revenue, Net									256,430	88,771	94,121
Component Test [Member]
Revenue from External Customer [Line Items]
Revenue, Net									32,790	22,381	19,901
Semiconductor [Member]
Revenue from External Customer [Line Items]
Revenue, Net									55,171	29,557	38,262
Industrial Machining [Member]
Revenue from External Customer [Line Items]
Revenue, Net									$ 23,493	$ 20,314	$ 32,107

Business Acquisitions - Allocat

Business Acquisitions - Allocation of Purchase Price of Assets Acquired and Liabilities Assumed Based on the Fair Value (Details) - USD ($) $ in Thousands	Aug. 01, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016	Jan. 15, 2015
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables					$ 268
Goodwill		$ 2,626	$ 3,027	$ 7,445
Cash paid to acquire subsidiaries		$ 0	$ 2,010	$ 0
Visicon [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	$ 391
Goodwill	2,626
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets	26
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	6,226
Payments to Acquire Businesses, Gross	2,000
Business Acquisition, Purchase Price Allocation, Current Assets, Inventory	982
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	737
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets	116
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	3,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	$ (1,952)

Business Acquisitions Business

Business Acquisitions Business Acquisition (Details) - USD ($) $ in Thousands	Aug. 01, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Compensation and Expenses for Business Acquisitions [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	$ 4,200
Business Combination, Integration Related Costs		$ 0	$ 366	$ 194
Visicon [Member]
Compensation and Expenses for Business Acquisitions [Line Items]
Payments to Acquire Businesses, Gross	$ 2,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	603,939
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 3,300
Topwin [Member]
Compensation and Expenses for Business Acquisitions [Line Items]
Business Combination, Integration Related Costs		$ 0
Developed Technology Rights [Member] | Visicon [Member]
Compensation and Expenses for Business Acquisitions [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 2,100

Uncategorized Items - esio-2018

Label	Element	Value
Cash, Cash Equivalents, and Restricted Cash; At Carrying Value	esio_CashCashEquivalentsandRestrictedCashAtCarryingValue	$ 50,994,000