Acquisitions - Intangible Assets Related to Acquisition (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	0 Months Ended
	Mar. 29, 2015	Mar. 29, 2015	Jun. 11, 2014	Dec. 31, 2014	Jan. 02, 2015	Mar. 31, 2014
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	$ 1,411,971	$ 1,411,971		$ 943,374
Tripwire [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	269,000	269,000
Goodwill	477,607	477,607			477,607
Intangible assets not subject to amortization	514,607	514,607
Total intangible assets	783,607	783,607
Weighted average amortization period	7 years 8 months 12 days
Tripwire [Member] | Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	31,000	31,000
Tripwire [Member] | Developed Technologies [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	210,000	210,000
Weighted average amortization period	5 years 9 months 18 days
Tripwire [Member] | Customer Relationships [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	56,000	56,000
Weighted average amortization period	15 years
Tripwire [Member] | Backlog [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	3,000	3,000
Weighted average amortization period	1 year
Tripwire [Member] | In-Process/Service Research and Development [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	6,000	6,000
Grass Valley [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	65,500	65,500
Goodwill	131,070	131,070				131,070
Intangible assets not subject to amortization	161,070	161,070
Total intangible assets	226,570	226,570
Weighted average amortization period		9 years
Grass Valley [Member] | Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	22,000	22,000
Grass Valley [Member] | Developed Technologies [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	37,000	37,000
Weighted average amortization period		5 years
Grass Valley [Member] | Customer Relationships [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	27,000	27,000
Weighted average amortization period		15 years
Grass Valley [Member] | Backlog [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization	1,500	1,500
Weighted average amortization period		3 months 18 days
Grass Valley [Member] | In-Process/Service Research and Development [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	8,000	8,000
Prosoft Technology, Inc. [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization			40,800
Goodwill			56,379
Intangible assets not subject to amortization			56,379
Total intangible assets			97,179
Weighted average amortization period			14 years 9 months 18 days
Prosoft Technology, Inc. [Member] | Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization			5,000
Weighted average amortization period			5 years
Prosoft Technology, Inc. [Member] | Developed Technologies [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization			9,000
Weighted average amortization period			5 years
Prosoft Technology, Inc. [Member] | Customer Relationships [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization			26,600
Weighted average amortization period			20 years
Prosoft Technology, Inc. [Member] | Backlog [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization			$ 200
Weighted average amortization period			3 months 18 days