Basis of Preparation and Summary of Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, $ in Thousands		12 Months Ended			24 Months Ended
	Mar. 11, 2018 USD ($) d $ / shares	Jun. 30, 2018 USD ($) customer Contract $ / shares	Jul. 01, 2017 USD ($) customer Contract $ / shares	Jul. 02, 2016 USD ($)	Jun. 30, 2018 USD ($) Contract $ / shares	Sep. 30, 2017 USD ($)	Sep. 21, 2016 $ / shares	Jun. 27, 2015 USD ($)
Business and Summary of Significant Accounting Policies [Line Items]
Accumulated deficit		$ (1,155,568)	$ (1,217,753)		$ (1,155,568)
Common stock, par value (in usd per share) | $ / shares		$ 0.01	$ 0.01		$ 0.01		$ 0.01
Loss on Contract Termination	$ 63,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Blended Rate, Percent		28.00%
Cash and cash equivalents		$ 245,688	$ 219,270	$ 95,929	$ 245,688			$ 111,840
Restricted cash		0	716		0
Short-term investments		$ 77,440	37,559		77,440
Operating cycle		52/53 week year ending on the Saturday closest to June 30
Net Cash Provided by (Used in) Operating Activities		$ 125,054	$ 95,554	$ 8,105
Fiscal year period		365 days	365 days	365 days
Allowances for doubtful accounts		$ 0	$ 0
Capitalized computer software costs		5,000	9,400		$ 14,400
Depreciation expense on property and equipment		29,500	20,800	$ 15,800
Loss on foreign currency transactions		$ (3,267)	$ 3,652	2,362
Number of foreign currency forward exchange contracts | Contract		0	0		0
Reduction in net deferred tax asset related to change in tax law		$ (35,000)
Gain (Loss) on Contract Termination	$ 80,000
Restructuring Acquisition And Related Gains (Losses)		4,300
Threshold Shares, Cash Consideration Increase per Share | $ / shares	$ 68.975
Trading Days Included in Average Closing Price | d	10
Business Acquisition, Share Price | $ / shares	$ 5.60
Additional paid-in capital		1,703,331	$ 1,688,777		$ 1,703,331
Foreign Currency Forward Exchange
Business and Summary of Significant Accounting Policies [Line Items]
Loss on foreign currency transactions		700	500
Opnext
Business and Summary of Significant Accounting Policies [Line Items]
Assets under capital lease		$ 3,200	$ 3,700		3,200
Minimum
Business and Summary of Significant Accounting Policies [Line Items]
Estimated useful of assets		3 years
Products warranty period from date of sale		12 months
Minimum | Stock Options
Business and Summary of Significant Accounting Policies [Line Items]
Award expected term		7 years
Award vesting period		2 years
Minimum | Restricted Stock Awards
Business and Summary of Significant Accounting Policies [Line Items]
Award vesting period		1 year
Maximum
Business and Summary of Significant Accounting Policies [Line Items]
Estimated useful of assets		7 years
Products warranty period from date of sale		36 months
Maximum | Stock Options
Business and Summary of Significant Accounting Policies [Line Items]
Award expected term		10 years
Award vesting period		4 years
Maximum | Restricted Stock Awards
Business and Summary of Significant Accounting Policies [Line Items]
Award vesting period		4 years
Foreign Subsidiaries
Business and Summary of Significant Accounting Policies [Line Items]
Cash and cash equivalents		$ 53,700			$ 53,700
Customer Concentration Risk | Accounts Receivable
Business and Summary of Significant Accounting Policies [Line Items]
Number of major customers | customer		2	1
Percentage of accounts receivable		36.00%			36.00%
Change
Business and Summary of Significant Accounting Policies [Line Items]
Net Cash Provided by (Used in) Operating Activities			$ 8,176	$ 1,838
Customer A | Customer Concentration Risk | Accounts Receivable
Business and Summary of Significant Accounting Policies [Line Items]
Percentage of accounts receivable		22.00%	20.00%		22.00%
Lumentum [Member]
Business and Summary of Significant Accounting Policies [Line Items]
Common stock, par value (in usd per share) | $ / shares	$ 0.001
Merger Consideration Threshold Shares, as Percent of Pre-merger Shares, Maximum	19.90%
Business Combination, Conversion Ratio of New Shares to Company Shares	0.0636
ZTE [Member]
Business and Summary of Significant Accounting Policies [Line Items]
Accounts Receivable, Gross		$ 500			$ 500
Inventory Write-down		3,100
Other Noncurrent Assets [Member]
Business and Summary of Significant Accounting Policies [Line Items]
Restricted cash		$ 200	$ 400		$ 200
Including Portion in Other Noncurrent Assets [Member]
Business and Summary of Significant Accounting Policies [Line Items]
Restricted cash			$ 1,100
Accounting Standards Update 2016-09
Business and Summary of Significant Accounting Policies [Line Items]
Accumulated deficit						$ 300
Additional paid-in capital						$ (300)