Mercury Systems (MRCY) 10-Q 2 Feb 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Dec. 31, 2017	Jan. 31, 2018
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Trading Symbol	MRCY
Entity Registrant Name	MERCURY SYSTEMS INC
Entity Central Index Key	1,049,521
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		48,242,590

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017
Current assets:
Cash and cash equivalents	$ 32,035		$ 41,637
Accounts receivable, net of allowance for doubtful accounts of $52 and $83 at December 31, 2017 and June 30, 2017, respectively	87,315		76,341
Unbilled receivables and costs in excess of billings	35,655		37,332
Inventory	105,912		81,071
Prepaid income taxes	15		1,434
Prepaid expenses and other current assets	7,970		8,381
Total current assets	268,902		246,196
Property and equipment, net	51,640		51,643
Estimated fair value of goodwill	384,785		380,846
Intangible assets, net	120,672		129,037
Other non-current assets	9,817		8,023
Total assets	835,816		815,745
Current liabilities:
Accounts payable	37,628		27,485
Accrued expenses	10,427		20,594
Accrued compensation	17,781		18,406
Deferred revenues and customer advances	8,440		6,360
Total current liabilities	74,276		72,845
Deferred income taxes	0		4,856
Income taxes payable	855		855
Other non-current liabilities	11,454		11,772
Total liabilities	86,585		90,328
Commitments and contingencies (Note M)
Shareholders' equity:
Preferred stock, $0.01 par value; 1,000,000 shares authorized; no shares issued or outstanding	0		0
Common stock, $0.01 par value; 85,000,000 shares authorized; 46,833,499 and 46,303,075 shares issued and outstanding at December 31, 2017 and June 30, 2017, respectively	468		463
Additional paid-in capital	581,534		584,795
Retained earnings	166,171		139,085
Accumulated other comprehensive income	1,058		1,074
Total shareholders' equity	749,231		725,417
Total liabilities and shareholders' equity	$ 835,816		$ 815,745

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Jun. 30, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 67	$ 92
Preferred stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (shares)	1,000,000	1,000,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	85,000,000	85,000,000
Common Stock, Shares, Issued (shares)	46,158,735	38,675,340
Common stock, shares outstanding (shares)	46,158,735	38,675,340

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net revenues	$ 117,912	$ 98,014	$ 223,981	$ 185,663
Cost of revenues	63,752	50,625	119,147	98,830
Gross margin	54,160	47,389	104,834	86,833
Operating expenses:
Selling, general and administrative	21,222	19,320	41,790	36,864
Research and development	15,187	13,156	28,929	25,994
Amortization of intangible assets	5,827	4,888	11,464	9,490
Restructuring and other charges	313	69	408	366
Acquisition costs and other related expenses	723	998	984	1,419
Total operating expenses	43,272	38,431	83,575	74,133
Income from operations	10,888	8,958	21,259	12,700
Interest income	3	10	22	50
Interest expense	(107)	(1,898)	(110)	(3,720)
Other income, net	(316)	(87)	(1,131)	513
Income before income taxes	10,468	6,983	20,040	9,543
Tax provision (benefit)	1,335	1,779	(7,046)	520
Net income	$ 9,133	$ 5,204	$ 27,086	$ 9,023
Basic net earnings per share (in dollars per share)	$ 0.20	$ 0.13	$ 0.58	$ 0.23
Diluted net earnings per share (in dollars per share)	$ 0.19	$ 0.13	$ 0.57	$ 0.23
Weighted-average shares outstanding:
Basic (in shares)	46,752	39,151	46,701	39,004
Diluted (in shares)	47,447	39,985	47,538	39,920
Comprehensive income:
Net income	$ 9,133	$ 5,204	$ 27,086	$ 9,023
Foreign currency translation adjustments	22	(341)	(56)	(333)
Pension benefit plan, net of tax	10	0	40	0
Total other comprehensive income, net of tax	32	(341)	(16)	(333)
Total comprehensive income	$ 9,165	$ 4,863	$ 27,070	$ 8,690

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 27,086	$ 9,023
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	18,939	15,176
Stock-based compensation expense	9,448	7,725
Benefit for deferred income taxes	(4,833)	(1,002)
Non-cash interest expense	0	935
Other non-cash items	847	(341)
Changes in operating assets and liabilities, net of effects of businesses acquired:
Accounts receivable, unbilled receivable, and cost in excess of billings	(9,181)	1,189
Inventory	(22,455)	(3,882)
Prepaid income taxes	1,414	(1,623)
Prepaid expenses and other current assets	(1,970)	376
Other non-current assets	(2,507)	(97)
Accounts payable and accrued expenses	11,597	(1,903)
Deferred revenues and customer advances	1,976	(1,310)
Income taxes payable	(11,284)	305
Other non-current liabilities	(2,270)	(50)
Net cash provided by operating activities	16,807	24,521
Cash flows from investing activities:
Acquisition of business, net of cash acquired	(5,798)	(38,764)
Purchases of property and equipment	(7,592)	(13,753)
Other investing activities	(375)	(111)
Net cash used in investing activities	(13,765)	(52,628)
Cash flows from financing activities:
Proceeds from employee stock plans	2,049	2,733
Payments for retirement of common stock	(14,909)	(7,560)
Payments under credit facilities	(15,000)	(2,500)
Borrowings under credit facilities	15,000	0
Net cash used in financing activities	(12,860)	(7,327)
Effect of exchange rate changes on cash and cash equivalents	216	(72)
Net decrease in cash and cash equivalents	(9,602)	(35,506)
Cash and cash equivalents at beginning of period	41,637	81,691
Cash and cash equivalents at end of period	32,035	46,185
Cash paid during the period for:
Interest	111	2,785
Income taxes	9,928	2,731
Supplemental disclosures—non-cash activities:
Non-cash investing activity	$ 0	$ 1,816

Description of Business

Description of Business	6 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Description of Business	Description of Business Mercury Systems, Inc. (the “Company” or “Mercury”) is a leading commercial provider of secure sensor and safety critical mission processing subsystems. Optimized for customer and mission success, its solutions power a wide variety of critical defense and intelligence programs. Headquartered in Andover, Massachusetts, it is pioneering a next-generation defense electronics business model specifically designed to meet the industry's current and emerging technology and business needs. The Company delivers affordable innovative solutions, rapid time-to-value and service and support primarily to defense prime contractor customers. The Company's products and solutions have been deployed in more than 300 programs with over 25 different defense prime contractors. Key programs include Aegis, Patriot, Surface Electronic Warfare Improvement Program ("SEWIP"), Gorgon Stare, Predator, F-16 SABR, F-35, E2D Hawkeye, Reaper and Paveway. The Company's organizational structure allows it to deliver capabilities that combine technology building blocks and deep domain expertise in the aerospace and defense sector.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies B ASIS OF P RESENTATION The accompanying consolidated financial statements have been prepared by the Company in accordance with Generally Accepted Accounting Principles ("GAAP") in the United States of America for interim financial information and with the instructions to the Form 10-Q and Article 10 of Regulation S-X. Certain information and footnote disclosures normally included in annual consolidated financial statements have been condensed or omitted pursuant to those rules and regulations; however, in the opinion of management the financial information reflects all adjustments, consisting of adjustments of a normal recurring nature, necessary for fair presentation. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes for the fiscal year ended June 30, 2017 which are contained in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on August 18, 2017. The results for the three and six months ended December 31, 2017 are not necessarily indicative of the results to be expected for the full fiscal year. The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. U SE OF E STIMATES The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. B USINESS C OMBINATIONS The Company utilizes the acquisition method of accounting under FASB ASC 805, Business Combinations , (“FASB ASC 805”), for all transactions and events which it obtains control over one or more other businesses, to recognize the fair value of all assets and liabilities acquired, even if less than one hundred percent ownership is acquired, and in establishing the acquisition date fair value as the measurement date for all assets and liabilities assumed. The Company also utilizes FASB ASC 805 for the initial recognition and measurement, subsequent measurement and accounting, and disclosure of assets and liabilities arising from contingencies in business combinations. F OREIGN C URRENCY Local currencies are the functional currency for the Company’s subsidiaries in Switzerland, United Kingdom, Japan and Canada. The accounts of foreign subsidiaries are translated using exchange rates in effect at period-end for assets and liabilities and at average exchange rates during the period for results of operations. The related translation adjustments are reported in accumulated other comprehensive income in shareholders’ equity. Gains (losses) resulting from non-U.S. currency transactions are included in other income (expense), net in the Consolidated Statements of Operations and Comprehensive Income and were immaterial for all periods presented. A CCOUNTS R ECEIVABLE F ACTORING On December 21, 2017, the Company executed a Master Receivables Purchase Agreement (the “Purchase Agreement”) with Bank of America, N.A. (the “Bank”) for the sale of certain eligible accounts receivable balances of the Company, up to a maximum of $30,000 . Factoring under the Purchase Agreement is treated as a true sale of accounts receivable by the Company. The Company has a continued involvement in servicing accounts receivable under the Purchase Agreement, but has no significant retained interests related to the factored accounts receivable. Proceeds from amounts factored by the Company are recorded as an increase to cash and a reduction to accounts receivable outstanding in the consolidated balance sheets. Cash flows attributable to factoring are reflected as cash flows from operating activities in the Company’s consolidated statements of cash flows. Factoring fees are included as selling, general, and administrative expenses in the Company’s consolidated statements of operations and comprehensive income. The Company factored accounts receivable and incurred factoring fees of $18,821 and $69 , respectively, for the three and six months ended December 31, 2017. R EVENUE R ECOGNITION The Company relies upon FASB ASC 605, Revenue Recognition, to account for its revenue transactions. Revenue is recognized upon shipment provided that title and risk of loss have passed to the customer, there is persuasive evidence of an arrangement, the sales price is fixed or determinable, collection of the related receivable is reasonably assured, and customer acceptance criteria, if any, have been successfully demonstrated. Out-of-pocket expenses that are reimbursable by the customer are included in revenue and cost of revenue. Certain contracts with customers require the Company to perform tests of its products prior to shipment to ensure their performance complies with the Company’s published product specifications and, on occasion, with additional customer-requested specifications. In these cases, the Company conducts such tests and, if they are completed successfully, includes a written confirmation with each order shipped. As a result, at the time of each product shipment, the Company believes that no further customer testing requirements exist and that there is no uncertainty of acceptance by its customer. The Company uses FASB Accounting Standards Update ("ASU") No. 2009-13 (“FASB ASU 2009-13”), Multiple-Deliverable Revenue Arrangements . FASB ASU 2009-13 establishes a selling price hierarchy for determining the selling price of a deliverable, which includes: (1) vendor-specific objective evidence (“VSOE”) if available; (2) third-party evidence (“TPE”) if VSOE is not available; and (3) best estimated selling price (“BESP”), if neither VSOE nor TPE is available. Additionally, FASB ASU 2009-13 expands the disclosure requirements related to a vendor’s multiple-deliverable revenue arrangements. The Company enters into multiple-deliverable arrangements that may include a combination of hardware components, related integration or other services. These arrangements generally do not include any performance-, cancellation-, termination- or refund-type provisions. Total revenue recognized under multiple-deliverable revenue arrangements was 37% and 38% of total revenue in the three and six months ended December 31, 2017 , respectively. Total revenue recognized under multiple-deliverable revenue arrangements was 23% and 29% of total revenues in the three and six months ended December 31, 2016 , respectively. In accordance with the provisions of FASB ASU 2009-13, the Company allocates arrangement consideration to each deliverable in an arrangement based on its relative selling price. The Company generally expects that it will not be able to establish VSOE or TPE due to limited single element transactions and the nature of the markets in which the Company competes, and, as such, the Company typically determines its relative selling price using BESP. The objective of BESP is to determine the price at which the Company would transact if the product or service were sold by the Company on a standalone basis. The Company's determination of BESP involves the consideration of several factors based on the specific facts and circumstances of each arrangement. Specifically, the Company considers the cost to produce the deliverable, the anticipated margin on that deliverable, the selling price and profit margin for similar parts, the Company’s ongoing pricing strategy and policies (as evident from the price list established and updated by management on a regular basis), the value of any enhancements that have been built into the deliverable and the characteristics of the varying markets in which the deliverable is sold. The Company analyzes the selling prices used in its allocation of arrangement consideration at a minimum on an annual basis. Selling prices will be analyzed on a more frequent basis if a significant change in the Company’s business necessitates a more timely analysis or if the Company experiences significant variances in its selling prices. Each deliverable within the Company’s multiple-deliverable revenue arrangements is accounted for as a separate unit of accounting under the guidance of FASB ASU 2009-13 if both of the following criteria are met: the delivered item or items have value to the customer on a standalone basis; and for an arrangement that includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is considered probable and substantially in the control of the Company. The Company's revenue arrangements generally do not include a general right of return relative to delivered products. The Company considers a deliverable to have standalone value if the item is sold separately by the Company or another vendor or if the item could be resold by the customer. Deliverables not meeting the criteria for being a separate unit of accounting are combined with a deliverable that does meet that criterion. The appropriate allocation of arrangement consideration and recognition of revenue is then determined for the combined unit of accounting. The Company also engages in long-term contracts for development, production and services activities which it accounts for consistent with FASB ASC 605-35, Accounting for Performance of Construction-Type and Certain Production-Type Contracts , and other relevant revenue recognition accounting literature. The Company considers the nature of these contracts and the types of products and services provided when determining the proper accounting for a particular contract. Generally for fixed-price contracts, other than service-type contracts, revenue is recognized primarily under the percentage of completion method or, for certain short-term contracts, by the completed contract method. Revenue from service-type fixed-price contracts is recognized ratably over the contract period or by other appropriate input or output methods to measure service provided, and contract costs are expensed as incurred. The Company establishes billing terms at the time project deliverables and milestones are agreed. The risk to the Company on a fixed-price contract is that if estimates to complete the contract change from one period to the next, profit levels will vary from period to period. For time and materials contracts, revenue reflects the number of direct labor hours expended in the performance of a contract multiplied by the contract billing rate, as well as reimbursement of other billable direct costs. For all types of contracts, the Company recognizes anticipated contract losses as soon as they become known and estimable. The Company also considers whether contracts should be combined or segmented in accordance with the applicable criteria under GAAP. The Company combines closely related contracts when all the applicable criteria under GAAP are met. The combination of two or more contracts requires judgment in determining whether the intent of entering into the contracts was effectively to enter into a single project, which should be combined to reflect an overall profit rate. Similarly, the Company may separate a project, which may consist of a single contract or group of contracts, with varying rates of profitability, only if the applicable criteria under GAAP are met. Judgment also is involved in determining whether a single contract or group of contracts may be segmented based on how the arrangement was negotiated and the performance criteria. The decision to combine a group of contracts or segment a contract could change the amount of revenue and gross profit recorded in a given period. The use of contract accounting requires significant judgment relative to estimating total contract revenues and costs, including assumptions relative to the length of time to complete the contract, the nature and complexity of the work to be performed, anticipated increases in wages and prices for subcontractor services and materials, and the availability of subcontractor services and materials. The Company’s estimates are based upon the professional knowledge and experience of its engineers, program managers and other personnel, who review each long-term contract monthly to assess the contract’s schedule, performance, technical matters and estimated cost at completion. Changes in estimates are applied retrospectively and when adjustments in estimated contract costs are identified, such revisions may result in current period adjustments to earnings applicable to performance in prior periods. Contract costs also may include estimated contract recoveries for matters such as contract changes and claims for unanticipated contract costs. The Company records revenue associated with these matters only when the amount of recovery can be estimated reliably and realization is probable. The Company defines service revenues as revenue from activities that are not associated with the design, development, production, or delivery of tangible assets, software or specific capabilities sold. Examples of the Company's service revenues include: analyst services and systems engineering support, consulting, maintenance and other support, testing and installation. The Company combines its product and service revenues into a single class as service revenues are less than 10 percent of total revenues. The Company does not provide its customers with rights of product return, other than those related to warranty provisions that permit repair or replacement of defective goods. The Company accrues for anticipated warranty costs upon product shipment. Revenues from product royalties are recognized upon invoice by the Company. Additionally, all revenues are reported net of government assessed taxes (e.g., sales taxes or value-added taxes). W EIGHTED -A VERAGE S HARES Weighted-average shares were calculated as follows: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Basic weighted-average shares outstanding 46,752 39,151 46,701 39,004 Effect of dilutive equity instruments 695 834 837 916 Diluted weighted-average shares outstanding 47,447 39,985 47,538 39,920 Equity instruments to purchase 23 and 162 shares of common stock were not included in the calculation of diluted net earnings per share for the three and six months ended December 31, 2017 , respectively, because the equity instruments were anti-dilutive. Equity instruments to purchase 9 and 6 shares of common stock were not included in the calculation of diluted net earnings per share for the three and six months ended December 31, 2016, respectively, because the equity instruments were anti-dilutive.

Acquisitions

Acquisitions	6 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	Acquisitions R ICHLAND TECHNOLOGIES A CQUISITION On July 3, 2017, the Company entered into a membership interest purchase agreement with Richland Technologies, L.L.C. ("RTL"), pursuant to which, the Company acquired RTL on a cash-free, debt-free basis for a total purchase price of $5,798 . RTL specializes in safety-critical and high integrity systems, software and hardware development as well as safety-certification services for mission-critical applications. The acquisition had an immaterial impact to the Company’s results of operations (contributed less than one percent of net revenue for the three and six months ended December 31, 2017 ), and accordingly the disclosures required per FASB ASC 805 have been excluded from the Form 10-Q filing. The Company recognized primarily intangible assets including customer relationships, developed technology and goodwill based on its preliminary purchase price allocation. D ELTA A CQUISITION On April 3, 2017, the Company entered into a membership interest purchase agreement with Delta Microwave, LLC ("Delta"), pursuant to which the Company acquired Delta on a cash-free, debt-free basis for a total purchase price of $40,500 , subject to net working capital and net debt adjustments. Delta is a designer and manufacturer of high-value RF, microwave and millimeter wave sub-assemblies and components for the military, aerospace and space markets. The acquisition and transaction related expenses were funded with cash on hand. The following table presents the net purchase price and the preliminary fair values of the assets and liabilities of Delta: Amounts Consideration transferred Cash paid at closing $ 40,500 Net purchase price $ 40,500 Estimated fair value of tangible assets acquired and liabilities assumed Accounts receivable and cost in excess of billings $ 957 Inventory 4,452 Fixed assets 1,918 Other current and non-current assets 67 Current liabilities (2,055 ) Estimated fair value of net tangible assets acquired 5,339 Estimated fair value of identifiable intangible assets 17,000 Estimated goodwill 18,161 Estimated fair value of net assets acquired 40,500 Net purchase price $ 40,500 The amounts above represent the preliminary fair value estimates as of December 31, 2017 and are subject to subsequent adjustment as the Company obtains additional information during the measurement period. The preliminary identifiable intangible asset estimates include customer relationships of $8,000 with a useful life of 9 years, developed technology of $5,900 with a useful life of 7 years and backlog of $3,100 with a useful life of 2 years. Any subsequent adjustments to these fair value estimates occurring during the measurement period will result in an adjustment to goodwill. The goodwill of $18,161 largely reflects the potential synergies and expansion of the Company's offerings across product lines and markets complementary to the Company's existing products and markets. The Delta acquisition expands the scale and breadth of the Company’s RF, microwave and millimeter wave capabilities, provides a highly complementary program portfolio in missiles and munitions, deepens market penetration in core radar, electronic warfare ("EW"), and precision-guided munitions markets, and opens new growth opportunities in space launch, GPS, satellite communications and datalinks. The goodwill from this acquisition is reported under the Advanced Microelectronic Solutions (“AMS”) reporting unit. Since Delta was a limited liability company, the acquisition is treated as an asset purchase for tax purposes. The Company has estimated the tax value of the intangible assets from this transaction and is amortizing the amount over 15 years for tax purposes. As of December 31, 2017 , the Company had $17,615 of goodwill deductible for tax purposes. The revenues and income before income taxes from Delta included in the Company's consolidated results for the three months ended December 31, 2017 were $5,229 and $74 , respectively. The revenues and income before income taxes from Delta included in the Company's consolidated results for the six months ended December 31, 2017 were $10,761 and $661 , respectively. The Company has not furnished pro forma financial information relating to Delta because such information is not material to the Company's financial results. C ES A QUISITION On November 4, 2016, the Company and the shareholders of CES entered into a Stock Purchase Agreement, pursuant to which, Mercury acquired CES for a total purchase price of $39,123 , subject to net working capital and net debt adjustments. The acquisition and associated transaction expenses were funded with cash on hand. Based in Geneva, Switzerland, CES is a leading provider of embedded solutions for military and aerospace mission-critical computing applications. CES specializes in the design, development and manufacture of safety-certifiable product and subsystems solutions including: primary flight control units, flight test computers, mission computers, command and control processors, graphics and video processing and avionics-certified Ethernet and IO. CES has decades of experience designing subsystems deployed in applications certified up to the highest levels of design assurance. CES products and solutions are used on platforms such as aerial refueling tankers and multi-mission aircraft, as well as the several types of unmanned platforms. The following table presents the net purchase price and the fair values of the assets and liabilities of CES: Amounts Consideration transferred Cash paid at closing $ 39,123 Working capital adjustment (330 ) Net purchase price $ 38,793 Fair value of tangible assets acquired and liabilities assumed Accounts receivable and cost in excess of billings $ 2,698 Inventory 8,950 Fixed assets 1,480 Other current and non-current assets 748 Current liabilities (3,154 ) Non-current liabilities (6,140 ) Deferred tax liabilities (1,148 ) Fair value of net tangible assets acquired 3,434 Fair value of identifiable intangible assets 14,722 Goodwill 20,637 Fair value of net assets acquired 38,793 Net purchase price $ 38,793 On November 3, 2017, the measurement period for CES expired. The identifiable intangible assets include customer relationships of $9,060 with a useful life of 9 years and developed technology of $5,662 with a useful life of 7 years. The goodwill of $20,637 largely reflects the potential synergies and expansion of the Company's offerings across product lines and markets complementary to the Company's existing products and markets. CES provides the Company with capabilities in mission computing, safety-critical avionics and platform management that are in demand from its customers. These new capabilities will also substantially expand Mercury’s addressable market into commercial aerospace, defense platform management, command, control, communications, computers, and intelligence ("C4I") and mission computing markets that are aligned to Mercury’s existing market focus. The acquisition is directly aligned with the Company's strategy of expanding its capabilities, services and offerings along the sensor processing chain. The goodwill from this acquisition is reported under the Sensor and Mission Processing (“SMP”) reporting unit. The revenues and income before income taxes from CES included in the Company's consolidated results for the three months ended December 31, 2017 were $7,000 and $2,445 , respectively. The revenues and income before income taxes from CES included in the Company's consolidated results for the six months ended December 31, 2017 were $13,319 and $2,093 , respectively. The Company has not furnished pro forma financial information relating to CES because such information is not material to the Company's financial results. T HEMIS C OMPUTER A QUISITION On December 21, 2017, the Company and Thunderbird Merger Sub, Inc., a newly formed, wholly-owned subsidiary of Mercury (the “Merger Sub”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Ceres Systems (“Ceres”), the holding company that owns Themis Computer (“Themis”, and together with Ceres, collectively the “Acquired Company”). Pursuant to the Merger Agreement, the Merger Sub will merge with and into Ceres with Ceres continuing as the surviving company and a wholly-owned subsidiary of Mercury (the “Merger”). By operation of the Merger, the Company acquired both Ceres and its wholly-owned subsidiary, Themis. On February 1, 2018, the Company closed the transaction for an aggregate purchase price of $180,000 , plus an estimated adjustment for acquired working capital and cash. The merger consideration is subject to post-closing adjustments based on a determination of closing net working capital, transaction expenses and net debt (all as defined in the Merger Agreement). See Note N "Subsequent Events" to the consolidated financial statements for further discussion.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The following table summarizes the Company’s financial assets measured at fair value on a recurring basis at December 31, 2017 : Fair Value Measurements December 31, 2017 Level 1 Level 2 Level 3 Assets: Certificates of deposit $ 1,048 $ — $ 1,048 $ — Total $ 1,048 $ — $ 1,048 $ — The carrying values of cash and cash equivalents, including money market funds, restricted cash, accounts receivable and payable, and accrued liabilities approximate fair value due to the short-term maturities of these assets and liabilities. The fair value of the Company’s certificates of deposit are determined through quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable. The cost-method investment, which is presented within other non-current assets in the accompanying consolidated balance sheets, does not have a readily determinable fair value, as such the Company recorded the investment at cost and will continue to evaluate the asset for impairment on a quarterly basis.

Inventory

Inventory	6 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory is stated at the lower of cost (first-in, first-out) or net realizable value, and consists of materials, labor and overhead. On a quarterly basis, the Company uses consistent methodologies to evaluate inventory for net realizable value. Once an item is written down, the value becomes the new inventory cost basis. The Company reduces the value of inventory for excess and obsolete inventory, consisting of on-hand inventory in excess of estimated usage. The excess and obsolete inventory evaluation is based upon assumptions about future demand, history, product mix and possible alternative uses. Inventory was comprised of the following: December 31, 2017 June 30, 2017 Raw materials $ 67,268 $ 48,645 Work in process 25,977 22,567 Finished goods 12,667 9,859 Total $ 105,912 $ 81,071 There are no amounts in inventory relating to contracts having production cycles longer than one year.

Goodwill

Goodwill	6 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill The following table sets forth the changes in the carrying amount of goodwill by reporting unit for the six months ended December 31, 2017 : SMP AMS MDS Total Balance at June 30, 2017 $ 116,003 $ 217,956 $ 46,887 $ 380,846 Goodwill adjustment for the CES acquisition 291 — — 291 Goodwill adjustment for the Delta acquisition — 201 — 201 Goodwill arising from the RTL acquisition 3,447 — — 3,447 Balance at December 31, 2017 $ 119,741 $ 218,157 $ 46,887 $ 384,785 In the six months ended December 31, 2017 , there were no triggering events, as defined by FASB ASC 350, Intangibles - Goodwill and Other , which required an interim goodwill impairment test. The Company performs its annual goodwill impairment test in the fourth quarter of each fiscal year.

Restructuring

Restructuring	6 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring The following table presents the detail of activity for the Company’s restructuring plans: Severance & Facilities Total Restructuring liability at June 30, 2017 $ 1,365 $ — $ 1,365 Restructuring and other charges 327 81 408 Cash paid (575 ) (81 ) (656 ) Restructuring liability at December 31, 2017 $ 1,117 $ — $ 1,117 During the six months ended December 31, 2017 , the Company incurred net restructuring and other charges of $408 . Restructuring and other charges are typically related to acquisitions and organizational redesign programs initiated as part of discrete post-acquisition integration activities. All of the restructuring and other charges are classified as operating expenses in the consolidated statements of operations and any remaining severance obligations are expected to be paid within the next twelve months. The restructuring liability is classified as accrued expenses in the consolidated balance sheets.

Income Taxes

Income Taxes	6 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) was enacted by the U.S. government. The Tax Act has impacted the U.S. statutory Federal tax rate that the Company will use going forward, which has been reduced to 21% from 35%. As the Company has a June 30 fiscal year-end, the lower corporate income tax rate will be phased in, resulting in a U.S. statutory Federal rate of approximately 28% for our fiscal year ending June 30, 2018, and 21% for subsequent fiscal years. The Tax Act also includes items that the Company expects will increase its tax expense including, but not limited to, the elimination of the domestic manufacturing deduction and increased limitations on executive compensation. In addition, the actual effective tax rate may be materially different than the statutory Federal tax rate (including being higher) based on the availability and impact of various other adjustments including but not limited to state taxes, Federal research and development credits, discrete tax benefits related to stock compensation, and the inclusion or exclusion of various items in taxable income which may differ from GAAP income. To transition to the reduced U.S. corporate tax rate, an adjustment is required to be made to our U.S. deferred tax assets and liabilities. For the three months ended December 31, 2017, the adjustment to the U.S. deferred tax assets and liabilities resulted in a tax benefit of $1,286 . The Tax Act includes a transition tax, which is a one-time tax charge on accumulated, undistributed foreign earnings. The calculation of accumulated foreign earnings requires an analysis of each foreign entity’s financial results going back to 1986, including historical tax information that is not yet available to management. The Company has not recorded any transition tax associated with its accumulated, undistributed foreign earnings given its current U.S. tax attributes, including the availability of foreign tax credits. For the three months ended December 31, 2017, the Company has recorded a provisional tax expense of $415 as it no longer expects to utilize certain foreign tax credits. The Company continues to evaluate its transition tax obligation and expects to finalize its conclusions by the end of fiscal 2018. The Company does not expect the final amounts to be materially different than those recorded within this period. For the three-months ended December 31, 2017, the Company has recorded all known and estimable impacts of the Tax Act that are effective for fiscal year 2018. In accordance with SEC Staff Accounting Bulletin 118 (“SAB 118”), future adjustments to the provisional numbers will be recorded as discrete adjustments to income tax expense in the period in which those adjustments become estimable and finalized. The Company recorded an income tax provision of $1,335 and $1,779 on income from operations before income taxes of $10,468 and $6,983 for the three months ended December 31, 2017 and 2016 , respectively. The Company recorded an income tax benefit of $7,046 and an income tax provision of $520 on income from operations before income taxes of $20,040 and $9,543 for the six months ended December 31, 2017 and 2016 , respectively. During the three months ended December 31, 2017 and 2016, the Company recognized a discrete tax expense and benefit of $294 and $634 , respectively, related to excess tax benefits on stock-based compensation. The discrete tax expense for the three months ended December 31, 2017 included the enactment of the Tax Act which revalued the excess tax benefit previously recorded in the three months ended September 30, 2017. The excess tax benefit related to stock-based compensation is the result of an increase in value from the stock award between the grant date and the vest date. The effective tax rate for the three months ended December 31, 2017 and 2016 differed from the Federal statutory rate primarily due to Federal research and development credits, domestic manufacturing deduction, excess tax benefits related to stock compensation, and state taxes. During the six months ended December 31, 2017 and 2016, the Company recognized a discrete tax benefit of $7,579 and $2,817 , respectively, related to excess tax benefits on stock-based compensation. The discrete tax benefit for the six months ended December 31, 2017 included the enactment of the Tax Act which revalued the excess tax benefit previously recorded in the three months ended September 30, 2017. The benefit is the result of the increase in value from the stock award between the grant date and the vest date. The six months ended December 31, 2017 also included discrete tax benefits of $3,716 , derived from new information obtained about net operating loss carry-forwards of the entities acquired from Microsemi Corporation in May 2016. The discrete items disclosed above for the six months ended December 31, 2017 included the effect of the Tax Act. The effective tax rate for the six months ended December 31, 2017 and 2016 differed from the Federal statutory rate primarily due to Federal research and development credits, domestic manufacturing deduction, excess tax benefits related to stock compensation, and state taxes. No material changes in the Company’s unrecognized tax positions occurred during the six months ended December 31, 2017 .

Debt

Debt	6 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt R EVOLVING C REDIT F ACILITY On June 27, 2017, the Company amended its revolving credit facility to increase and extend the borrowing capacity of its existing revolving credit facility into a $400,000 , 5 -year revolving credit line expiring in June 2022 (“the Revolver”). As of December 31, 2017 , the Company's outstanding balance of unamortized deferred financing costs was $5,991 , which is being amortized to other (expense) income, net on a straight line basis over the new term of the Revolver. The Company drew $195,000 from the Revolver to facilitate the completion of the Merger Agreement for the acquisition of both Ceres and its wholly-owned subsidiary, Themis. As of December 31, 2017, the Company was in compliance with all covenants and conditions under the Revolver and there were no outstanding borrowings against the revolver. There were outstanding letters of credit of $2,760 as of December 31, 2017 .

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation S TOCK O PTION P LANS The number of shares authorized for issuance under the Company’s 2005 Stock Incentive Plan, as amended and restated (the “2005 Plan”), is 15,252 shares at December 31, 2017 . The 2005 Plan provides for the grant of non-qualified and incentive stock options, restricted stock, stock appreciation rights and deferred stock awards to employees and non-employees. All stock options are granted with an exercise price of not less than 100% of the fair value of the Company’s common stock at the date of grant and the options generally have a term of seven years. There were 1,496 shares available for future grant under the 2005 Plan at December 31, 2017 . As part of the Company's ongoing annual equity grant program for employees, the Company grants performance-based restricted stock awards to certain executives and employees pursuant to the 2005 Plan. Performance awards vest based on the requisite service period subject to the achievement of specific financial performance targets. Based on the performance targets, some of these awards require graded vesting which results in more rapid expense recognition compared to traditional time-based vesting over the same vesting period. The Company monitors the probability of achieving the performance targets on a quarterly basis and may adjust periodic stock compensation expense accordingly based on its determination of the likelihood for reaching targets. The performance targets include: (i) the achievement of internal performance targets only, and (ii) the achievement of internal performance targets in relation to a peer group of companies. E MPLOYEE S TOCK P URCHASE P LAN The number of shares authorized for issuance under the Company’s 1997 Employee Stock Purchase Plan, as amended and restated (“ESPP”), is 1,800 shares. Under the ESPP, rights are granted to purchase shares of common stock at 85% of the lesser of the market value of such shares at either the beginning or the end of each six-month offering period. The ESPP permits employees to purchase common stock through payroll deductions, which may not exceed 10% of an employee’s compensation as defined in the ESPP. There were 39 and 50 shares issued under the ESPP during the six months ended December 31, 2017 and 2016 , respectively. Shares available for future purchase under the ESPP totaled 263 at December 31, 2017 . S TOCK O PTION AND A WARD A CTIVITY The following table summarizes activity of the Company’s stock option plans since June 30, 2017 : Options Outstanding Number of Weighted Average Weighted Average Outstanding at June 30, 2017 51 $ 13.53 0.60 Granted — — Exercised (47 ) 14.12 Canceled — — Outstanding at December 31, 2017 4 $ 5.52 3.60 The following table summarizes the status of the Company’s non-vested restricted stock awards since June 30, 2017 : Non-vested Restricted Stock Awards Number of Weighted Average Outstanding at June 30, 2017 1,564 $ 18.93 Granted 453 47.46 Vested (758 ) 17.02 Forfeited (42 ) 26.28 Outstanding at December 31, 2017 1,217 $ 30.47 S TOCK - BASED C OMPENSATION E XPENSE The Company recognizes expense for its share-based payment plans in the consolidated statements of operations for the six months ended December 31, 2017 and 2016 in accordance with FASB ASC 718, Compensation - Stock Compensation . The Company had $265 and $177 of capitalized stock-based compensation expense on the consolidated balance sheets as of December 31, 2017 and 2016 , respectively. Under the fair value recognition provisions of FASB ASC 718, stock-based compensation cost is measured at the grant date based on the value of the award and is recognized as expense over the service period, net of estimated forfeitures. The following table presents share-based compensation expenses included in the Company’s consolidated statements of operations: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Cost of revenues $ 47 $ 148 $ 195 $ 223 Selling, general and administrative 4,270 3,539 8,246 6,578 Research and development 510 406 1,007 924 Stock-based compensation expense before tax 4,827 4,093 9,448 7,725 Income taxes (1,593 ) (1,575 ) (3,118 ) (2,964 ) Stock-based compensation expense, net of income taxes $ 3,234 $ 2,518 $ 6,330 $ 4,761

Employee Benefit Plan Employee

Employee Benefit Plan Employee Benefit Plan	6 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plan	P ENSION P LAN With the acquisition of CES on November 4, 2016, the Company assumed a defined benefit pension plan (the "Plan") for its Swiss employees, which is administered by an independent pension fund. The Plan is mandated by Swiss law and meets the criteria for a defined benefit plan under ASC 715, Compensation—Retirement Benefits (“ASC 715”), because participants of the Plan are entitled to a defined rate of return on contributions made. The independent pension fund is a multi-employer plan with unrestricted joint liability for all participating companies for which the Plan’s overfunding or underfunding is allocated to each participating company based on an allocation key determined by the Plan. The Company recognizes a net asset or liability for the Plan equal to the difference between the projected benefit obligation of the Plan and the fair value of the Plan’s assets as required by ASC 715. The funded status may vary from year to year due to changes in the fair value of the Plan’s assets and variations on the underlying assumptions of the projected benefit obligation of the Plan. The Plan's funded status at December 31, 2017 was a net liability of $6,647 , which is recorded in other non-current liabilities on the consolidated balance sheets. The Company recorded a net gain of $10 and $40 in accumulated other comprehensive income during the three and six months ended December 31, 2017 , respectively. The Company recognized net periodic benefit costs of $201 and $407 associated with the Plan for the three and six months ended December 31, 2017 , respectively. The Company's total expected employer contributions to the Plan during fiscal 2018 are $516 .

Operating Segment, Geographic I

Operating Segment, Geographic Information and Significant Customers	6 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Operating Segment, Geographic Information and Significant Customers	Operating Segment, Geographic Information and Significant Customers Operating segments are defined as components of an enterprise evaluated regularly by the Company's chief operating decision maker (“CODM”) in deciding how to allocate resources and assess performance. The Company is comprised of one operating and reportable segment. The Company utilized the management approach for determining its operating segment in accordance with FASB ASC 280, Segment Reporting . The geographic distribution of the Company’s revenues as determined by order origination based on the country in which the Company's legal subsidiary is domiciled is summarized as follows: U.S. Europe Asia Pacific Eliminations Total THREE MONTHS ENDED DECEMBER 31, 2017 Net revenues to unaffiliated customers $ 105,687 $ 9,417 $ 2,808 $ — $ 117,912 Inter-geographic revenues 3,169 43 — (3,212 ) — Net revenues $ 108,856 $ 9,460 $ 2,808 $ (3,212 ) $ 117,912 T HREE M ONTHS E NDED DECEMBER 31 , 2016 Net revenues to unaffiliated customers $ 91,407 $ 5,809 $ 798 $ — $ 98,014 Inter-geographic revenues 1,893 — — (1,893 ) — Net revenues $ 93,300 $ 5,809 $ 798 $ (1,893 ) $ 98,014 SIX M ONTHS E NDED DECEMBER 31, 2017 Net revenues to unaffiliated customers $ 203,402 $ 16,895 $ 3,684 $ — $ 223,981 Inter-geographic revenues 4,916 65 — (4,981 ) — Net revenues $ 208,318 $ 16,960 $ 3,684 $ (4,981 ) $ 223,981 SIX M ONTHS E NDED DECEMBER 31 , 2016 Net revenues to unaffiliated customers $ 174,455 $ 6,662 $ 4,546 $ — $ 185,663 Inter-geographic revenues 5,180 15 — (5,195 ) — Net revenues $ 179,635 $ 6,677 $ 4,546 $ (5,195 ) $ 185,663 In recent years, the Company completed a series of acquisitions that changed its technological capabilities, applications and end markets. As these acquisitions and changes occurred, the Company increased the proportion of its revenue derived from the sale of components in different technological areas, and also increased the amount of revenue associated with combining technologies into more complex and diverse products including modules, sub-assemblies and integrated subsystems. The following tables present revenue consistent with the Company's strategy of expanding its technological capabilities and program content. The following table below presents the Company's net revenue by end user for the periods presented: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Domestic (1) $ 89,969 $ 83,052 $ 179,647 $ 156,578 International/Foreign Military Sales (2) 27,943 14,962 44,334 29,085 Total Net Revenue $ 117,912 $ 98,014 $ 223,981 $ 185,663 (1) Domestic revenues consist of sales where the end user is within the U.S., as well as sales to prime defense contractor customers where the ultimate end user location is not defined. (2) International/Foreign Military Sales consist of sales to U.S. prime defense contractor customers where the end user is known to be outside the U.S., foreign military sales through the U.S. government, and direct sales to non-U.S. based customers intended for end use outside of the U.S. The following table below presents the Company's net revenue by end application for the periods presented: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Radar (1) $ 44,678 $ 44,803 $ 81,218 $ 82,292 Electronic Warfare (2) 29,411 21,304 57,419 42,284 Other Sensor & Effector (3) 10,992 4,661 20,741 9,307 Total Sensor & Effector 85,081 70,768 159,378 133,883 C4I (4) 13,562 6,613 26,388 10,953 Other (5) 19,269 20,633 38,215 40,827 Total Net Revenue $ 117,912 $ 98,014 $ 223,981 $ 185,663 (1) Radar includes end-use applications where radio frequency signals are utilized to detect, track, and identify objects. (2) Electronic Warfare includes end-use applications comprising the offensive and defensive use of the electromagnetic spectrum. (3) Other Sensor & Effector products include all Sensor & Effector end markets other than Radar and Electronic Warfare. (4) C4I includes rugged secure rackmount servers that are designed to drive the most powerful military processing applications. (5) Other products include all component and other sales where the end use is not specified. The following table below presents the Company's net revenue by product grouping for the periods presented: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Components (1) $ 39,908 $ 24,636 $ 72,720 $ 44,468 Modules and Sub-assemblies (2) 41,728 38,560 89,460 75,152 Integrated Subsystems (3) 36,276 34,818 61,801 66,043 Total Net Revenue $ 117,912 $ 98,014 $ 223,981 $ 185,663 (1) Components include technology elements typically performing a single, discrete technological function, which when physically combined with other components may be used to create a module or sub-assembly. Examples include but are not limited to power amplifiers and limiters, switches, oscillators, filters, equalizers, digital and analog converters, chips, MMICs (monolithic microwave integrated circuits), and memory and storage devices. (2) Modules and Sub-assemblies include combinations of multiple functional technology elements and/or components that work together to perform multiple functions but are typically resident on or within a single board or housing. Modules and sub-assemblies may in turn be combined to form an integrated subsystem. Examples of modules and sub-assemblies include but are not limited to embedded processing modules, embedded processing boards, switch fabric boards, high speed input/output boards, digital receiver boards, graphics and video processing and Ethernet and IO (input-output) boards, multi-chip modules, integrated radio frequency and microwave multi-function assemblies, tuners, and transceivers. (3) Integrated Subsystems include multiple modules and/or subassemblies combined with a backplane or similar functional element and software to enable a solution. These are typically but not always integrated within a chassis and with cooling, power and other elements to address various requirements and are also often combined with additional technologies for interaction with other parts of a complete system or platform. Integrated subsystems also include spare and replacement modules and sub-assemblies sold as part of the same program for use in or with integrated subsystems sold by the Company. The geographic distribution of the Company’s long-lived assets is summarized as follows: U.S. Europe Asia Pacific Eliminations Total December 31, 2017 $ 50,305 $ 1,323 $ 12 $ — $ 51,640 June 30, 2017 $ 50,340 $ 1,288 $ 15 $ — $ 51,643 Identifiable long-lived assets exclude goodwill and intangible assets. Customers comprising 10% or more of the Company’s revenues for the periods shown below are as follows: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Lockheed Martin Corporation 20 % 13 % 19 % 19 % Raytheon Company 17 % 22 % 19 % 19 % Northrop Grumman Corporation 12 % 10 % 11 % * 49 % 45 % 49 % 38 % * Indicates that the amount is less than 10% of the Company’s revenues for the respective period. While the Company typically has customers from which it derives 10% or more of its revenue, the sales to each of these customers are spread across multiple programs and platforms. Programs comprising 10% or more of the Company’s revenues for the periods shown below are as follows: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 F-35 * 11 % * * Aegis * * * 10 % — % 11 % — % 10 % * Indicates that the amount is less than 10% of the Company’s revenues for the respective period.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies L EGAL C LAIMS The Company is subject to litigation, claims, investigations and audits arising from time to time in the ordinary course of its business. Although legal proceedings are inherently unpredictable, the Company believes that it has valid defenses with respect to any matters currently pending against the Company and intends to defend itself vigorously. The outcome of these matters, individually and in the aggregate, is not expected to have a material impact on the Company’s cash flows, results of operations, or financial position. I NDEMNIFICATION O BLIGATIONS The Company’s standard product sales and license agreements entered into in the ordinary course of business typically contain an indemnification provision pursuant to which the Company indemnifies, holds harmless, and agrees to reimburse the indemnified party for losses suffered or incurred by the indemnified party in connection with any patent, copyright or other intellectual property infringement claim by any third party with respect to the Company’s products. Such provisions generally survive termination or expiration of the agreements. The potential amount of future payments the Company could be required to make under these indemnification provisions is, in some instances, unlimited. P URCHASE C OMMITMENTS As of December 31, 2017 , the Company has entered into non-cancelable purchase commitments for certain inventory components and services used in its normal operations. The purchase commitments covered by these agreements are for less than one year and aggregate to $50,653 . O THER As part of the Company's strategy for growth, the Company continues to explore acquisitions or strategic alliances. The associated acquisition costs incurred in the form of professional fees and services may be material to the future periods in which they occur, regardless of whether the acquisition is ultimately completed. The Company may elect from time to time to purchase and subsequently retire shares of common stock in order to settle employees’ tax liabilities associated with vesting of a restricted stock award or exercise of stock options. These transactions would be treated as a use of cash in financing activities in the Company's statement of cash flows.

Subsequent Events

Subsequent Events	6 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events T HEMIS C OMPUTER A QUISITION On December 21, 2017, the Merger Sub, entered into the Merger Agreement with Ceres, the holding company that owns Themis. Pursuant to the Merger Agreement, the Merger Sub will merge with and into Ceres with Ceres continuing as the surviving company and a wholly-owned subsidiary of Mercury. By operation of the Merger, the Company acquired both Ceres and its wholly-owned subsidiary, Themis. Based in Fremont, California, Themis is a leading designer and manufacturer of commercial, SWaP-optimized rugged servers, computers, and storage systems for U.S. and international defense programs. Under the terms of the Merger Agreement, the merger consideration (including payments with respect to outstanding stock options) consisted of an all cash purchase price of $180,000 , without interest. The merger consideration is subject to post-closing adjustments based on a determination of closing net working capital, transaction expenses and net debt (all as defined in the Merger Agreement). A related escrow agreement establishes an escrow amount of $1,500 in respect of post-closing adjustments owed to the Company and an escrow amount of $900 in respect of indemnification obligations to the Company. On February 1, 2018, the Company closed the transaction for an aggregate purchase price of $180,000 , plus an estimated adjustment for acquired working capital and cash. The Company drew $195,000 on the Revolver to facilitate the closing of the acquisition, with the higher amount reflecting an estimated adjustment for working capital, including cash, expected to be received with the Acquired Company at closing. The Company has not completed its preliminary purchase price allocation for Ceres as not all information required for the analysis was available. G ENERAL The Company has evaluated subsequent events from the date of the consolidated balance sheet through the date the consolidated financial statements were issued.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	B ASIS OF P RESENTATION The accompanying consolidated financial statements have been prepared by the Company in accordance with Generally Accepted Accounting Principles ("GAAP") in the United States of America for interim financial information and with the instructions to the Form 10-Q and Article 10 of Regulation S-X. Certain information and footnote disclosures normally included in annual consolidated financial statements have been condensed or omitted pursuant to those rules and regulations; however, in the opinion of management the financial information reflects all adjustments, consisting of adjustments of a normal recurring nature, necessary for fair presentation. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes for the fiscal year ended June 30, 2017 which are contained in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on August 18, 2017. The results for the three and six months ended December 31, 2017 are not necessarily indicative of the results to be expected for the full fiscal year. The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation
Use of Estimates	U SE OF E STIMATES The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
Business Combinations	B USINESS C OMBINATIONS The Company utilizes the acquisition method of accounting under FASB ASC 805, Business Combinations , (“FASB ASC 805”), for all transactions and events which it obtains control over one or more other businesses, to recognize the fair value of all assets and liabilities acquired, even if less than one hundred percent ownership is acquired, and in establishing the acquisition date fair value as the measurement date for all assets and liabilities assumed. The Company also utilizes FASB ASC 805 for the initial recognition and measurement, subsequent measurement and accounting, and disclosure of assets and liabilities arising from contingencies in business combinations.
Foreign Currency	F OREIGN C URRENCY Local currencies are the functional currency for the Company’s subsidiaries in Switzerland, United Kingdom, Japan and Canada. The accounts of foreign subsidiaries are translated using exchange rates in effect at period-end for assets and liabilities and at average exchange rates during the period for results of operations. The related translation adjustments are reported in accumulated other comprehensive income in shareholders’ equity. Gains (losses) resulting from non-U.S. currency transactions are included in other income (expense), net in the Consolidated Statements of Operations and Comprehensive Income and were immaterial for all periods presented.
Accounts Receivable Factoring	On December 21, 2017, the Company executed a Master Receivables Purchase Agreement (the “Purchase Agreement”) with Bank of America, N.A. (the “Bank”) for the sale of certain eligible accounts receivable balances of the Company, up to a maximum of $30,000 . Factoring under the Purchase Agreement is treated as a true sale of accounts receivable by the Company. The Company has a continued involvement in servicing accounts receivable under the Purchase Agreement, but has no significant retained interests related to the factored accounts receivable. Proceeds from amounts factored by the Company are recorded as an increase to cash and a reduction to accounts receivable outstanding in the consolidated balance sheets. Cash flows attributable to factoring are reflected as cash flows from operating activities in the Company’s consolidated statements of cash flows. Factoring fees are included as selling, general, and administrative expenses in the Company’s consolidated statements of operations and comprehensive income.
Revenue Recognition	R EVENUE R ECOGNITION The Company relies upon FASB ASC 605, Revenue Recognition, to account for its revenue transactions. Revenue is recognized upon shipment provided that title and risk of loss have passed to the customer, there is persuasive evidence of an arrangement, the sales price is fixed or determinable, collection of the related receivable is reasonably assured, and customer acceptance criteria, if any, have been successfully demonstrated. Out-of-pocket expenses that are reimbursable by the customer are included in revenue and cost of revenue. Certain contracts with customers require the Company to perform tests of its products prior to shipment to ensure their performance complies with the Company’s published product specifications and, on occasion, with additional customer-requested specifications. In these cases, the Company conducts such tests and, if they are completed successfully, includes a written confirmation with each order shipped. As a result, at the time of each product shipment, the Company believes that no further customer testing requirements exist and that there is no uncertainty of acceptance by its customer. The Company uses FASB Accounting Standards Update ("ASU") No. 2009-13 (“FASB ASU 2009-13”), Multiple-Deliverable Revenue Arrangements . FASB ASU 2009-13 establishes a selling price hierarchy for determining the selling price of a deliverable, which includes: (1) vendor-specific objective evidence (“VSOE”) if available; (2) third-party evidence (“TPE”) if VSOE is not available; and (3) best estimated selling price (“BESP”), if neither VSOE nor TPE is available. Additionally, FASB ASU 2009-13 expands the disclosure requirements related to a vendor’s multiple-deliverable revenue arrangements. The Company enters into multiple-deliverable arrangements that may include a combination of hardware components, related integration or other services. These arrangements generally do not include any performance-, cancellation-, termination- or refund-type provisions. Total revenue recognized under multiple-deliverable revenue arrangements was 37% and 38% of total revenue in the three and six months ended December 31, 2017 , respectively. Total revenue recognized under multiple-deliverable revenue arrangements was 23% and 29% of total revenues in the three and six months ended December 31, 2016 , respectively. In accordance with the provisions of FASB ASU 2009-13, the Company allocates arrangement consideration to each deliverable in an arrangement based on its relative selling price. The Company generally expects that it will not be able to establish VSOE or TPE due to limited single element transactions and the nature of the markets in which the Company competes, and, as such, the Company typically determines its relative selling price using BESP. The objective of BESP is to determine the price at which the Company would transact if the product or service were sold by the Company on a standalone basis. The Company's determination of BESP involves the consideration of several factors based on the specific facts and circumstances of each arrangement. Specifically, the Company considers the cost to produce the deliverable, the anticipated margin on that deliverable, the selling price and profit margin for similar parts, the Company’s ongoing pricing strategy and policies (as evident from the price list established and updated by management on a regular basis), the value of any enhancements that have been built into the deliverable and the characteristics of the varying markets in which the deliverable is sold. The Company analyzes the selling prices used in its allocation of arrangement consideration at a minimum on an annual basis. Selling prices will be analyzed on a more frequent basis if a significant change in the Company’s business necessitates a more timely analysis or if the Company experiences significant variances in its selling prices. Each deliverable within the Company’s multiple-deliverable revenue arrangements is accounted for as a separate unit of accounting under the guidance of FASB ASU 2009-13 if both of the following criteria are met: the delivered item or items have value to the customer on a standalone basis; and for an arrangement that includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is considered probable and substantially in the control of the Company. The Company's revenue arrangements generally do not include a general right of return relative to delivered products. The Company considers a deliverable to have standalone value if the item is sold separately by the Company or another vendor or if the item could be resold by the customer. Deliverables not meeting the criteria for being a separate unit of accounting are combined with a deliverable that does meet that criterion. The appropriate allocation of arrangement consideration and recognition of revenue is then determined for the combined unit of accounting. The Company also engages in long-term contracts for development, production and services activities which it accounts for consistent with FASB ASC 605-35, Accounting for Performance of Construction-Type and Certain Production-Type Contracts , and other relevant revenue recognition accounting literature. The Company considers the nature of these contracts and the types of products and services provided when determining the proper accounting for a particular contract. Generally for fixed-price contracts, other than service-type contracts, revenue is recognized primarily under the percentage of completion method or, for certain short-term contracts, by the completed contract method. Revenue from service-type fixed-price contracts is recognized ratably over the contract period or by other appropriate input or output methods to measure service provided, and contract costs are expensed as incurred. The Company establishes billing terms at the time project deliverables and milestones are agreed. The risk to the Company on a fixed-price contract is that if estimates to complete the contract change from one period to the next, profit levels will vary from period to period. For time and materials contracts, revenue reflects the number of direct labor hours expended in the performance of a contract multiplied by the contract billing rate, as well as reimbursement of other billable direct costs. For all types of contracts, the Company recognizes anticipated contract losses as soon as they become known and estimable. The Company also considers whether contracts should be combined or segmented in accordance with the applicable criteria under GAAP. The Company combines closely related contracts when all the applicable criteria under GAAP are met. The combination of two or more contracts requires judgment in determining whether the intent of entering into the contracts was effectively to enter into a single project, which should be combined to reflect an overall profit rate. Similarly, the Company may separate a project, which may consist of a single contract or group of contracts, with varying rates of profitability, only if the applicable criteria under GAAP are met. Judgment also is involved in determining whether a single contract or group of contracts may be segmented based on how the arrangement was negotiated and the performance criteria. The decision to combine a group of contracts or segment a contract could change the amount of revenue and gross profit recorded in a given period. The use of contract accounting requires significant judgment relative to estimating total contract revenues and costs, including assumptions relative to the length of time to complete the contract, the nature and complexity of the work to be performed, anticipated increases in wages and prices for subcontractor services and materials, and the availability of subcontractor services and materials. The Company’s estimates are based upon the professional knowledge and experience of its engineers, program managers and other personnel, who review each long-term contract monthly to assess the contract’s schedule, performance, technical matters and estimated cost at completion. Changes in estimates are applied retrospectively and when adjustments in estimated contract costs are identified, such revisions may result in current period adjustments to earnings applicable to performance in prior periods. Contract costs also may include estimated contract recoveries for matters such as contract changes and claims for unanticipated contract costs. The Company records revenue associated with these matters only when the amount of recovery can be estimated reliably and realization is probable. The Company defines service revenues as revenue from activities that are not associated with the design, development, production, or delivery of tangible assets, software or specific capabilities sold. Examples of the Company's service revenues include: analyst services and systems engineering support, consulting, maintenance and other support, testing and installation. The Company combines its product and service revenues into a single class as service revenues are less than 10 percent of total revenues. The Company does not provide its customers with rights of product return, other than those related to warranty provisions that permit repair or replacement of defective goods. The Company accrues for anticipated warranty costs upon product shipment. Revenues from product royalties are recognized upon invoice by the Company. Additionally, all revenues are reported net of government assessed taxes (e.g., sales taxes or value-added taxes).
Weighted-Average Shares	W EIGHTED -A VERAGE S HARES Weighted-average shares were calculated as follows: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Basic weighted-average shares outstanding 46,752 39,151 46,701 39,004 Effect of dilutive equity instruments 695 834 837 916 Diluted weighted-average shares outstanding 47,447 39,985 47,538 39,920 Equity instruments to purchase 23 and 162 shares of common stock were not included in the calculation of diluted net earnings per share for the three and six months ended December 31, 2017 , respectively, because the equity instruments were anti-dilutive. Equity instruments to purchase 9 and 6 shares of common stock were not included in the calculation of diluted net earnings per share for the three and six months ended December 31, 2016, respectively, because the equity instruments were anti-dilutive.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basic and Diluted Weighted Average Shares Outstanding	Weighted-average shares were calculated as follows: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Basic weighted-average shares outstanding 46,752 39,151 46,701 39,004 Effect of dilutive equity instruments 695 834 837 916 Diluted weighted-average shares outstanding 47,447 39,985 47,538 39,920

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of the Net Purchase Price and Fair Values of Assets and Liabilities Acquired	The following table presents the net purchase price and the fair values of the assets and liabilities of CES: Amounts Consideration transferred Cash paid at closing $ 39,123 Working capital adjustment (330 ) Net purchase price $ 38,793 Fair value of tangible assets acquired and liabilities assumed Accounts receivable and cost in excess of billings $ 2,698 Inventory 8,950 Fixed assets 1,480 Other current and non-current assets 748 Current liabilities (3,154 ) Non-current liabilities (6,140 ) Deferred tax liabilities (1,148 ) Fair value of net tangible assets acquired 3,434 Fair value of identifiable intangible assets 14,722 Goodwill 20,637 Fair value of net assets acquired 38,793 Net purchase price $ 38,793 The following table presents the net purchase price and the preliminary fair values of the assets and liabilities of Delta: Amounts Consideration transferred Cash paid at closing $ 40,500 Net purchase price $ 40,500 Estimated fair value of tangible assets acquired and liabilities assumed Accounts receivable and cost in excess of billings $ 957 Inventory 4,452 Fixed assets 1,918 Other current and non-current assets 67 Current liabilities (2,055 ) Estimated fair value of net tangible assets acquired 5,339 Estimated fair value of identifiable intangible assets 17,000 Estimated goodwill 18,161 Estimated fair value of net assets acquired 40,500 Net purchase price $ 40,500

Fair Value of Financial Instr23

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value	The following table summarizes the Company’s financial assets measured at fair value on a recurring basis at December 31, 2017 : Fair Value Measurements December 31, 2017 Level 1 Level 2 Level 3 Assets: Certificates of deposit $ 1,048 $ — $ 1,048 $ — Total $ 1,048 $ — $ 1,048 $ —

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventory	Inventory was comprised of the following: December 31, 2017 June 30, 2017 Raw materials $ 67,268 $ 48,645 Work in process 25,977 22,567 Finished goods 12,667 9,859 Total $ 105,912 $ 81,071

Goodwill (Tables)

Goodwill (Tables)	6 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	The following table sets forth the changes in the carrying amount of goodwill by reporting unit for the six months ended December 31, 2017 : SMP AMS MDS Total Balance at June 30, 2017 $ 116,003 $ 217,956 $ 46,887 $ 380,846 Goodwill adjustment for the CES acquisition 291 — — 291 Goodwill adjustment for the Delta acquisition — 201 — 201 Goodwill arising from the RTL acquisition 3,447 — — 3,447 Balance at December 31, 2017 $ 119,741 $ 218,157 $ 46,887 $ 384,785

Restructuring (Tables)

Restructuring (Tables)	6 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Expenses by Reportable Segment for Restructuring Plans	The following table presents the detail of activity for the Company’s restructuring plans: Severance & Facilities Total Restructuring liability at June 30, 2017 $ 1,365 $ — $ 1,365 Restructuring and other charges 327 81 408 Cash paid (575 ) (81 ) (656 ) Restructuring liability at December 31, 2017 $ 1,117 $ — $ 1,117

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Plans	The following table summarizes activity of the Company’s stock option plans since June 30, 2017 : Options Outstanding Number of Weighted Average Weighted Average Outstanding at June 30, 2017 51 $ 13.53 0.60 Granted — — Exercised (47 ) 14.12 Canceled — — Outstanding at December 31, 2017 4 $ 5.52 3.60
Summary of Nonvested Restricted Stock	The following table summarizes the status of the Company’s non-vested restricted stock awards since June 30, 2017 : Non-vested Restricted Stock Awards Number of Weighted Average Outstanding at June 30, 2017 1,564 $ 18.93 Granted 453 47.46 Vested (758 ) 17.02 Forfeited (42 ) 26.28 Outstanding at December 31, 2017 1,217 $ 30.47
Stock Based Compensation Expenses	The following table presents share-based compensation expenses included in the Company’s consolidated statements of operations: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Cost of revenues $ 47 $ 148 $ 195 $ 223 Selling, general and administrative 4,270 3,539 8,246 6,578 Research and development 510 406 1,007 924 Stock-based compensation expense before tax 4,827 4,093 9,448 7,725 Income taxes (1,593 ) (1,575 ) (3,118 ) (2,964 ) Stock-based compensation expense, net of income taxes $ 3,234 $ 2,518 $ 6,330 $ 4,761

Operating Segment, Geographic28

Operating Segment, Geographic Information and Significant Customers (Tables)	6 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Geographic Distribution of Revenues and Long Lived Assets from Continuing Operations	The following table below presents the Company's net revenue by end user for the periods presented: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Domestic (1) $ 89,969 $ 83,052 $ 179,647 $ 156,578 International/Foreign Military Sales (2) 27,943 14,962 44,334 29,085 Total Net Revenue $ 117,912 $ 98,014 $ 223,981 $ 185,663 (1) Domestic revenues consist of sales where the end user is within the U.S., as well as sales to prime defense contractor customers where the ultimate end user location is not defined. (2) International/Foreign Military Sales consist of sales to U.S. prime defense contractor customers where the end user is known to be outside the U.S., foreign military sales through the U.S. government, and direct sales to non-U.S. based customers intended for end use outside of the U.S. The following table below presents the Company's net revenue by end application for the periods presented: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Radar (1) $ 44,678 $ 44,803 $ 81,218 $ 82,292 Electronic Warfare (2) 29,411 21,304 57,419 42,284 Other Sensor & Effector (3) 10,992 4,661 20,741 9,307 Total Sensor & Effector 85,081 70,768 159,378 133,883 C4I (4) 13,562 6,613 26,388 10,953 Other (5) 19,269 20,633 38,215 40,827 Total Net Revenue $ 117,912 $ 98,014 $ 223,981 $ 185,663 (1) Radar includes end-use applications where radio frequency signals are utilized to detect, track, and identify objects. (2) Electronic Warfare includes end-use applications comprising the offensive and defensive use of the electromagnetic spectrum. (3) Other Sensor & Effector products include all Sensor & Effector end markets other than Radar and Electronic Warfare. (4) C4I includes rugged secure rackmount servers that are designed to drive the most powerful military processing applications. (5) Other products include all component and other sales where the end use is not specified. The following table below presents the Company's net revenue by product grouping for the periods presented: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Components (1) $ 39,908 $ 24,636 $ 72,720 $ 44,468 Modules and Sub-assemblies (2) 41,728 38,560 89,460 75,152 Integrated Subsystems (3) 36,276 34,818 61,801 66,043 Total Net Revenue $ 117,912 $ 98,014 $ 223,981 $ 185,663 (1) Components include technology elements typically performing a single, discrete technological function, which when physically combined with other components may be used to create a module or sub-assembly. Examples include but are not limited to power amplifiers and limiters, switches, oscillators, filters, equalizers, digital and analog converters, chips, MMICs (monolithic microwave integrated circuits), and memory and storage devices. (2) Modules and Sub-assemblies include combinations of multiple functional technology elements and/or components that work together to perform multiple functions but are typically resident on or within a single board or housing. Modules and sub-assemblies may in turn be combined to form an integrated subsystem. Examples of modules and sub-assemblies include but are not limited to embedded processing modules, embedded processing boards, switch fabric boards, high speed input/output boards, digital receiver boards, graphics and video processing and Ethernet and IO (input-output) boards, multi-chip modules, integrated radio frequency and microwave multi-function assemblies, tuners, and transceivers. (3) Integrated Subsystems include multiple modules and/or subassemblies combined with a backplane or similar functional element and software to enable a solution. These are typically but not always integrated within a chassis and with cooling, power and other elements to address various requirements and are also often combined with additional technologies for interaction with other parts of a complete system or platform. Integrated subsystems also include spare and replacement modules and sub-assemblies sold as part of the same program for use in or with integrated subsystems sold by the Company. The geographic distribution of the Company’s long-lived assets is summarized as follows: U.S. Europe Asia Pacific Eliminations Total December 31, 2017 $ 50,305 $ 1,323 $ 12 $ — $ 51,640 June 30, 2017 $ 50,340 $ 1,288 $ 15 $ — $ 51,643 The geographic distribution of the Company’s revenues as determined by order origination based on the country in which the Company's legal subsidiary is domiciled is summarized as follows: U.S. Europe Asia Pacific Eliminations Total THREE MONTHS ENDED DECEMBER 31, 2017 Net revenues to unaffiliated customers $ 105,687 $ 9,417 $ 2,808 $ — $ 117,912 Inter-geographic revenues 3,169 43 — (3,212 ) — Net revenues $ 108,856 $ 9,460 $ 2,808 $ (3,212 ) $ 117,912 T HREE M ONTHS E NDED DECEMBER 31 , 2016 Net revenues to unaffiliated customers $ 91,407 $ 5,809 $ 798 $ — $ 98,014 Inter-geographic revenues 1,893 — — (1,893 ) — Net revenues $ 93,300 $ 5,809 $ 798 $ (1,893 ) $ 98,014 SIX M ONTHS E NDED DECEMBER 31, 2017 Net revenues to unaffiliated customers $ 203,402 $ 16,895 $ 3,684 $ — $ 223,981 Inter-geographic revenues 4,916 65 — (4,981 ) — Net revenues $ 208,318 $ 16,960 $ 3,684 $ (4,981 ) $ 223,981 SIX M ONTHS E NDED DECEMBER 31 , 2016 Net revenues to unaffiliated customers $ 174,455 $ 6,662 $ 4,546 $ — $ 185,663 Inter-geographic revenues 5,180 15 — (5,195 ) — Net revenues $ 179,635 $ 6,677 $ 4,546 $ (5,195 ) $ 185,663
Customers Comprising Ten Percent or More Revenues	Customers comprising 10% or more of the Company’s revenues for the periods shown below are as follows: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 Lockheed Martin Corporation 20 % 13 % 19 % 19 % Raytheon Company 17 % 22 % 19 % 19 % Northrop Grumman Corporation 12 % 10 % 11 % * 49 % 45 % 49 % 38 % * Indicates that the amount is less than 10% of the Company’s revenues for the respective period.
Schedules of Concentration of Risk, by Risk Factor	Programs comprising 10% or more of the Company’s revenues for the periods shown below are as follows: Three Months Ended December 31, Six Months Ended December 31, 2017 2016 2017 2016 F-35 * 11 % * * Aegis * * * 10 % — % 11 % — % 10 % * Indicates that the amount is less than 10% of the Company’s revenues for the respective period.

Description of Business (Detail

Description of Business (Details)	6 Months Ended
	Dec. 31, 2017programcontractor
Accounting Policies [Abstract]
Number of programs using products and services | program	300
Number of defense prime contractors using products and services | contractor	25

Summary of Significant Accoun30

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 21, 2017
Significant Accounting Policies [Line Items]
Purchase agreement, maximum receivable balances					$ 30,000,000
Accounts receivable and incurred factoring fees	$ 18,821,000		$ 69,000
Multiple Delivery Revenue [Member]
Significant Accounting Policies [Line Items]
Percentage Of revenue recognized	37.00%	23.00%	38.00%	29.00%

Summary of Significant Accoun31

Summary of Significant Accounting Policies -Basic and Diluted Weighted Average Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Basic weighted-average shares outstanding (in shares)	46,752	39,151	46,701	39,004
Effect of dilutive equity instruments (in shares)	695	834	837	916
Diluted weighted-average shares outstanding (in shares)	47,447	39,985	47,538	39,920
Antidilutive securities excluded from computation of earnings per share (in shares)	23	9	162	6

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Thousands	Feb. 01, 2018	Jul. 03, 2017	Apr. 03, 2017	Nov. 04, 2016	Dec. 31, 2017	Dec. 31, 2017	Jun. 30, 2017
Business Acquisition [Line Items]
Estimated fair value of goodwill					$ 384,785	$ 384,785	$ 380,846
RTL
Business Acquisition [Line Items]
Total purchase price		$ 5,798
Delta
Business Acquisition [Line Items]
Total purchase price			$ 40,500
Estimated fair value of goodwill			18,161
Intangible assets acquired, amortization period						15 years
Tax deductible goodwill					17,615	$ 17,615
Revenue of acquiree since acquisition date					5,229	10,761
Net income (loss) of acquiree since acquisition date					74	661
Cash paid at closing			40,500
Delta | Customer Relationships
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired			$ 8,000
Useful life of acquired assets			9 years
Delta | Developed Technology Rights
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired			$ 5,900
Useful life of acquired assets			7 years
Delta | Backlog
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired			$ 3,100
Useful life of acquired assets			2 years
CES Creative Electronic Systems S.A.
Business Acquisition [Line Items]
Estimated fair value of goodwill				$ 20,637
Revenue of acquiree since acquisition date					7,000	13,319
Net income (loss) of acquiree since acquisition date					$ 2,445	$ 2,093
Cash paid at closing				39,123
CES Creative Electronic Systems S.A. | Customer Relationships
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired				$ 9,060
Useful life of acquired assets				9 years
CES Creative Electronic Systems S.A. | Developed Technology Rights
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired				$ 5,662
Useful life of acquired assets				7 years
Themis Computer Acquisition | Subsequent Event
Business Acquisition [Line Items]
Total purchase price	$ 180,000

Acquisitions - Net Purchase Pri

Acquisitions - Net Purchase Price and Fair Values of Assets and Liabilities Acquired (Details) - USD ($) $ in Thousands	Apr. 03, 2017	Nov. 04, 2016	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2017
Consideration transferred
Net purchase price			$ 5,798	$ 38,764
Estimated fair value of tangible assets acquired and liabilities assumed
Estimated fair value of goodwill			$ 384,785		$ 380,846
Delta
Consideration transferred
Cash paid at closing	$ 40,500
Net purchase price	40,500
Estimated fair value of tangible assets acquired and liabilities assumed
Accounts receivable and cost in excess of billings	957
Inventory	4,452
Fixed assets	1,918
Other current and non-current assets	67
Current liabilities	(2,055)
Fair value of net tangible assets acquired	5,339
Fair value of identifiable intangible assets	17,000
Estimated fair value of goodwill	18,161
Estimated fair value of assets acquired	40,500
Net purchase price	$ 40,500
CES Creative Electronic Systems S.A.
Consideration transferred
Cash paid at closing		$ 39,123
Working capital adjustment		(330)
Net purchase price		38,793
Estimated fair value of tangible assets acquired and liabilities assumed
Accounts receivable and cost in excess of billings		2,698
Inventory		8,950
Fixed assets		1,480
Other current and non-current assets		748
Current liabilities		(3,154)
Non-current liabilities		(6,140)
Deferred tax liabilities		(1,148)
Fair value of net tangible assets acquired		3,434
Fair value of identifiable intangible assets		14,722
Estimated fair value of goodwill		20,637
Estimated fair value of assets acquired		$ 38,793

Fair Value of Financial Instr34

Fair Value of Financial Instruments - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value - Fair Value, Measurements, Recurring $ in Thousands	Dec. 31, 2017USD ($)
Assets:
Fair value measurement disclosure	$ 1,048
Certificates of deposit
Assets:
Fair value measurement disclosure	1,048
Level 1
Assets:
Fair value measurement disclosure	0
Level 1 | Certificates of deposit
Assets:
Fair value measurement disclosure	0
Level 2
Assets:
Fair value measurement disclosure	1,048
Level 2 | Certificates of deposit
Assets:
Fair value measurement disclosure	1,048
Level 3
Assets:
Fair value measurement disclosure	0
Level 3 | Certificates of deposit
Assets:
Fair value measurement disclosure	$ 0

Inventory (Detail)

Inventory (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Jun. 30, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 67,268	$ 48,645
Work in process	25,977	22,567
Finished goods	12,667	9,859
Total	$ 105,912	$ 81,071

Inventory - Additional Informat

Inventory - Additional Information (Detail) - Product	6 Months Ended
	Dec. 31, 2017USD ($)
Schedule of Inventory [Line Items]
Inventory relating to contracts having production cycles longer than one year	$ 0
Production cycle term (in years)	P1Y

Changes in Carrying Amount of G

Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Dec. 31, 2017USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 380,846
Ending Balance	384,785
SMP
Goodwill [Roll Forward]
Beginning Balance	116,003
Ending Balance	119,741
AMS
Goodwill [Roll Forward]
Beginning Balance	217,956
Ending Balance	218,157
MDS
Goodwill [Roll Forward]
Beginning Balance	46,887
Ending Balance	46,887
CES Creative Electronic Systems S.A.
Goodwill [Roll Forward]
Goodwill arising from the RTL acquisition	291
CES Creative Electronic Systems S.A. | SMP
Goodwill [Roll Forward]
Goodwill arising from the RTL acquisition	291
Delta
Goodwill [Roll Forward]
Goodwill arising from the RTL acquisition	201
Delta | AMS
Goodwill [Roll Forward]
Goodwill arising from the RTL acquisition	201
RTL
Goodwill [Roll Forward]
Goodwill arising from the RTL acquisition	3,447
RTL | SMP
Goodwill [Roll Forward]
Goodwill arising from the RTL acquisition	$ 3,447

Restructuring - Expenses by Rep

Restructuring - Expenses by Reportable Segment for Restructuring Plans (Detail) $ in Thousands	6 Months Ended
	Dec. 31, 2017USD ($)
Restructuring Reserve [Roll Forward]
Restructuring liability at June 30, 2017	$ 1,365
Restructuring and other charges	408
Cash paid	(656)
Restructuring liability at December 31, 2017	1,117
Severance & Related
Restructuring Reserve [Roll Forward]
Restructuring liability at June 30, 2017	1,365
Restructuring and other charges	327
Cash paid	(575)
Restructuring liability at December 31, 2017	1,117
Facilities & Other
Restructuring Reserve [Roll Forward]
Restructuring liability at June 30, 2017	0
Restructuring and other charges	81
Cash paid	(81)
Restructuring liability at December 31, 2017	$ 0

Restructuring - Additional Info

Restructuring - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Other Income and Expenses [Abstract]
Restructuring expenses	$ 313	$ 69	$ 408	$ 366

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal statutory rate, blended rate for next fiscal year	28.00%		28.00%
Federal statutory rate in periods subsequent to next fiscal year	21.00%		21.00%
Deferred tax assets, effect of Tax Cuts and Jobs Act, tax expense (benefit)			$ 1,286
Provisional tax expense for foreign tax credits	$ 415
Income tax (benefit) expense	1,335	$ 1,779	(7,046)	$ 520
(Loss) income from operations before income taxes	10,468	6,983	20,040	9,543
Excess tax benefits on stock-based compensation	$ 294	$ 634	7,579	$ 2,817
Operating loss carryforward, increase in carrying value			$ 3,716

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	Feb. 01, 2018	Jun. 27, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Amount of outstanding letter of credit			$ 2,760,000
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 400,000,000
Debt instrument term		5 years
Revolving Credit Facility | Subsequent Event
Debt Instrument [Line Items]
Proceeds from lines of credit	$ 195,000,000
Term Loan
Debt Instrument [Line Items]
Debt issuance costs			$ 5,991,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocation of recognized period costs, capitalized amount	$ 265	$ 177
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance under stock incentive plan (in shares)	1,800
Shares available for future grant (in shares)	263
Purchase price as a percentage of the lesser of the market value of such shares at either the beginning or the end of each nine-month offering period	85.00%
Percentage of employee compensation that may be uses to purchase common stock through payroll deductions, maximum	10.00%
Granted (in shares)	39	50
2005 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance under stock incentive plan (in shares)	15,252
Exercise price of stock option, percentage	100.00%
Shares available for future grant (in shares)	1,496
2005 Stock Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of stock option	7 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Plans (Detail) - Stock Options - $ / shares shares in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017
Number of Shares
Outstanding at beginning of period (in shares)	51
Granted (in shares)	0
Exercised (in shares)	(47)
Cancelled (in shares)	0
Outstanding at end of period (in shares)	4	51
Weighted Average Exercise Price
Outstanding at beginning of period (usd per share)	$ 13.53
Granted (usd per share)	0
Exercised (usd per share)	14.12
Cancelled (usd per share)	0
Outstanding at end of period (usd per share)	$ 5.52	$ 13.53
Weighted Average Remaining Contractual Term (Years)
Outstanding at end of period	3 years 7 months 6 days	7 months 5 days

Stock-Based Compensation - Su44

Stock-Based Compensation - Summary of Nonvested Restricted Stock (Detail) - Restricted Stock shares in Thousands	6 Months Ended
	Dec. 31, 2017$ / sharesshares
Number of Shares
Beginning Balance (in shares) | shares	1,564
Granted (in shares) | shares	453
Vested (in shares) | shares	(758)
Forfeited (in shares) | shares	(42)
Ending Balance (in shares) | shares	1,217
Weighted Average Grant Date Fair Value
Beginning Balance (usd per share) | $ / shares	$ 18.93
Granted (usd per share) | $ / shares	47.46
Vested (usd per share) | $ / shares	17.02
Forfeited (usd per share) | $ / shares	26.28
Ending Balance (usd per share) | $ / shares	$ 30.47

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before tax	$ 4,827	$ 4,093	$ 9,448	$ 7,725
Income taxes	(1,593)	(1,575)	(3,118)	(2,964)
Net compensation expense	3,234	2,518	6,330	4,761
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before tax	47	148	195	223
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before tax	4,270	3,539	8,246	6,578
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before tax	$ 510	$ 406	$ 1,007	$ 924

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Pension benefit plan, net of tax	$ 10	$ 0	$ 40	$ 0
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	201		407
Fiscal 2017 cash contributions to plan			516
Pension Plan | Other Noncurrent Liabilities
Defined Benefit Plan Disclosure [Line Items]
Net funded status of plan	$ 6,647		$ 6,647

Operating Segment, Geographic47

Operating Segment, Geographic Information and Significant Customers - Geographic Distribution of Revenues and Long Lived Assets from Continuing Operations (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)	Jun. 30, 2017USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			1
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	$ 117,912	$ 98,014	$ 223,981	$ 185,663
Identifiable long-lived assets	51,640		51,640		$ 51,643
Components
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	39,908	24,636	72,720	44,468
Modules and Sub-assemblies
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	41,728	38,560	89,460	75,152
Integrated Subsystems
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	36,276	34,818	61,801	66,043
Total Sensor & Effector
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	85,081	70,768	159,378	133,883
Radar
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	44,678	44,803	81,218	82,292
Electronic Warfare
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	29,411	21,304	57,419	42,284
Other Sensor & Effector
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	10,992	4,661	20,741	9,307
C4I
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	13,562	6,613	26,388	10,953
Other End Applications
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	19,269	20,633	38,215	40,827
Domestic
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	89,969	83,052	179,647	156,578
International/Foreign Military Sales
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	27,943	14,962	44,334	29,085
US
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	105,687	91,407	203,402	174,455
Europe
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	9,417	5,809	16,895	6,662
Asia Pacific
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	2,808	798	3,684	4,546
Reportable Geographical Components | US
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	108,856	93,300	208,318	179,635
Identifiable long-lived assets	50,305		50,305		50,340
Reportable Geographical Components | Europe
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	9,460	5,809	16,960	6,677
Identifiable long-lived assets	1,323		1,323		1,288
Reportable Geographical Components | Asia Pacific
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	2,808	798	3,684	4,546
Identifiable long-lived assets	12		12		15
Geography Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	(3,212)	(1,893)	(4,981)	(5,195)
Identifiable long-lived assets	0		0		$ 0
Geography Eliminations | US
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	(3,169)	(1,893)	(4,916)	(5,180)
Geography Eliminations | Europe
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	(43)	0	(65)	(15)
Geography Eliminations | Asia Pacific
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenues	$ 0	$ 0	$ 0	$ 0

Operating Segment, Geographic48

Operating Segment, Geographic Information and Significant Customers - Customers Comprising Ten Percent or more Revenues (Detail) - Sales Revenue, Net	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Revenue, Major Customer [Line Items]
Concentration risk, percentage	0.00%	11.00%	0.00%	10.00%
Customer Concentration Risk
Revenue, Major Customer [Line Items]
Concentration risk, percentage	49.00%	45.00%	49.00%	38.00%
Customer Concentration Risk | Lockheed Martin Corporation
Revenue, Major Customer [Line Items]
Concentration risk, percentage	20.00%	13.00%	19.00%	19.00%
Customer Concentration Risk | Raytheon Company
Revenue, Major Customer [Line Items]
Concentration risk, percentage	17.00%	22.00%	19.00%	19.00%
Customer Concentration Risk | Northrop Grumman Corporation
Revenue, Major Customer [Line Items]
Concentration risk, percentage	12.00%	10.00%	11.00%

Operating Segment, Geographic49

Operating Segment, Geographic Information and Significant Customers - Programs Comprising Ten Percent or more of Company's Revenue (Detail) - Sales Revenue, Net	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Concentration risk, percentage	0.00%	11.00%	0.00%	10.00%
Program Concentration Risk | F-35
Segment Reporting Information [Line Items]
Concentration risk, percentage		11.00%
Program Concentration Risk | Aegis
Segment Reporting Information [Line Items]
Concentration risk, percentage				10.00%

Commitments And Contingencies -

Commitments And Contingencies - Additional Information (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Non-cancelable purchase commitments
Long-term Purchase Commitment [Line Items]
Purchase commitments for less than one year	$ 50,653

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event $ in Thousands	Feb. 01, 2018USD ($)
Revolving Credit Facility
Subsequent Event [Line Items]
Proceeds from lines of credit	$ 195,000
Themis Computer Acquisition
Subsequent Event [Line Items]
Total purchase price	180,000
Consideration, escrow amount, post-closing adjustments	1,500
Consideration, escrow amount, indemnification obligation	$ 900