Summary of Estimated Fair Values of Net Assets Acquired (Detail) - USD ($) $ in Thousands		Dec. 01, 2017	Jun. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill			$ 2,259,177	$ 2,278,512
Ruckus Wireless and ICX Switch business (Ruckus Networks)
Business Acquisition [Line Items]
Total estimated consideration transferred		$ 761,013
Cash and cash equivalents		18,958
Accounts receivable, net		25,030
Inventories		48,436
Prepaids & other		3,831
Property, plant & equipment		35,514
Intangible assets		494,700	494,700
Other assets		1,656
Accounts payable and accrued liabilities		(14,866)
Other current liabilities		(11,654)
Deferred revenue		(46,748)
Noncurrent deferred income tax liabilities		(99,876)
Other noncurrent liabilities		(2,210)
Net assets acquired		452,771
Goodwill		308,242	$ 308,200
Ruckus Wireless and ICX Switch business (Ruckus Networks) | As Reported
Business Acquisition [Line Items]
Total estimated consideration transferred	[1]	761,013
Cash and cash equivalents	[1]	18,958
Accounts receivable, net	[1]	32,940
Inventories	[1]	48,897
Prepaids & other	[1]	4,836
Property, plant & equipment	[1]	33,500
Intangible assets	[1]	472,500
Other assets	[1]	39,528
Accounts payable and accrued liabilities	[1]	(17,216)
Other current liabilities	[1]	(9,666)
Deferred revenue	[1]	(47,718)
Noncurrent deferred income tax liabilities	[1]	(92,233)
Other noncurrent liabilities	[1]	(41,347)
Net assets acquired	[1]	442,979
Goodwill	[1]	318,034
Ruckus Wireless and ICX Switch business (Ruckus Networks) | Adjustments
Business Acquisition [Line Items]
Accounts receivable, net		(7,910)
Inventories		(461)
Prepaids & other		(1,005)
Property, plant & equipment		2,014
Intangible assets		22,200
Other assets		(37,872)
Accounts payable and accrued liabilities		2,350
Other current liabilities		(1,988)
Deferred revenue		970
Noncurrent deferred income tax liabilities		(7,643)
Other noncurrent liabilities		39,137
Net assets acquired		9,792
Goodwill		$ (9,792)

[1] As previously reported as of December 31, 2017