Acquisitions - Fair Value of Assets Acquired and Liabilities Assumed (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 29, 2014	Dec. 31, 2013	Jun. 11, 2014 Prosoft Technology, Inc. [Member]	Mar. 31, 2014 Grass Valley [Member]
Business Acquisition [Line Items]
Cash			$ 2,492	$ 9,397
Receivables			6,026	73,324
Inventories			7,001	19,777
Other current assets			615	4,172
Property, plant and equipment			1,151	23,071
Goodwill	934,285	773,048	55,281	106,176
Intangible assets			37,400	95,500
Other non-current assets			78	26,919
Total assets			110,044	358,336
Accounts payable			2,455	50,870
Accrued liabilities			1,654	58,633
Deferred revenue				14,000
Postretirement benefits				15,604
Other non-current liabilities			935	1,199
Total liabilities			5,044	140,306
Net assets			$ 105,000	$ 218,030