Acquisitions, Divestiture and Investment - Additional Information (Detail) - USD ($) $ in Millions			1 Months Ended	3 Months Ended				6 Months Ended
	Jul. 17, 2020	Jul. 02, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 26, 2020	Dec. 31, 2019	Dec. 28, 2019	Dec. 31, 2020	Dec. 26, 2020	Dec. 31, 2019	Dec. 28, 2019	Jun. 30, 2020	Jun. 27, 2020
Business Acquisition [Line Items]
Goodwill			$ 568.6	$ 568.6	$ 568.6			$ 568.6	$ 568.6			$ 360.8	$ 360.8
Increase in Prepaid Expense					2.3
Other long-term liabilities					0.4				0.4
Fair value of other acquired net tangible assets					1.9
Revenue				$ 357.6		$ 388.3		$ 686.0		$ 728.2
Asset Purchase Agreement [Member]
Business Acquisition [Line Items]
Cash consideration receivable on divestiture of business			35.0
Gain on sale of the assets			34.2
Display Link Corporation [Member]
Business Acquisition [Line Items]
Acquisition agreement date	Jul. 17, 2020
Business acquisition, ownership percentage	100.00%
Purchase price included in cash	$ 305.0
Acquisition closing effective date	Jul. 31, 2020
Business combination, consideration transferred									442.8
Goodwill	$ 105.0
Business acquisition, Goodwill expected income tax deductible amount					0.0				0.0
Revenue									45.0
Pro forma adjustments to net income/(loss)					6.9		$ (9.7)		8.0		$ (18.4)
Prepaid expenses and other current assets	9.1
Non-current other assets	0.6
Display Link Corporation [Member] | Escrow Obligations Under Purchase Agreement [Member]
Business Acquisition [Line Items]
Purchase price held in escrow	$ 3.1
Business Acquisition [Member]
Business Acquisition [Line Items]
Goodwill					2.3				2.3
Broadcom Wireless Connectivity [Member]
Business Acquisition [Line Items]
Acquisition agreement date		Jul. 02, 2020
Purchase price included in cash		$ 250.0
Acquisition closing effective date		Jul. 23, 2020
Revenue									39.4
Business combination description		We acquired these assets and assumed certain liabilities from Broadcom in order to obtain wireless connectivity technology which will enhance our current IoT business
Transition agreements duration		3 years
Identified intangible assets included discount rates								2.20%
Identified intangible assets included discount rates								13.00%
Broadcom Wireless Connectivity [Member] | Derivative and Roadmap Product Agreement [Member]
Business Acquisition [Line Items]
Purchase price included in cash									2.0
Business combination, consideration transferred									3.5
Business combination, cost of services									25.0
Prepaid expenses and other current assets					10.0				10.0
Non-current other assets					15.0				15.0
Business combination, non-current other assets after amortization					$ 10.8				$ 10.8
Eta Compute [Member]
Business Acquisition [Line Items]
Purchase price included in cash			$ 5.0