Acquisitions - Additional Information (Detail) (USD $)	6 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Dec. 30, 2014	Dec. 31, 2014	Jun. 17, 2014	Jun. 30, 2014	Jun. 13, 2014	Dec. 31, 2013	Jun. 30, 2013
Business Acquisition [Line Items]
Goodwill	$ 530,889,000		$ 530,889,000		$ 540,952,000		$ 251,370,000	$ 234,342,000
IPSG/VFX [Member]
Business Acquisition [Line Items]
Goodwill		9,263,000
Preliminary valuation of contingent consideration	7,700,000
Acquired intangible assets		4,537,000
IPSG/VFX [Member] | Harman International Industries Pty Ltd [Member]
Business Acquisition [Line Items]
Purchase price		5,000,000
Acquisition earn-out contingent payable		7,700,000
Holdback percentage of contingent payable		15.00%
Number of years expected to occur certain days		18 months
Business acquisition date	Dec. 30, 2014
Goodwill		9,300,000
Goodwill amount deductible for tax purposes		0
Acquisition costs incurred	300,000		300,000
IPSG/VFX [Member] | Maximum [Member] | Harman International Industries Pty Ltd [Member]
Business Acquisition [Line Items]
Acquisition earn-out contingent payable		8,000,000
IPSG/VFX [Member] | Technology [Member] | Harman International Industries Pty Ltd [Member]
Business Acquisition [Line Items]
Approximate useful life		5 years
Yurbuds [Member]
Business Acquisition [Line Items]
Purchase price				37,000,000
Acquisition earn-out contingent payable				3,700,000
Number of years expected to occur certain days				18 months
Business acquisition date	Jun. 17, 2014
Goodwill				31,200,000
Goodwill amount deductible for tax purposes				0
Acquisition costs incurred					500,000
Number of days for working capital adjustment				120 days
Cash paid to acquire entity				32,500,000
Maximum acquisition earn-out				38,000,000
Preliminary valuation of contingent consideration				6,200,000
Acquired intangible assets				6,400,000
Purchase price inventories				7,587,000
Property, plant and equipment				2,928,000
Yurbuds [Member] | Tradenames [Member]
Business Acquisition [Line Items]
Acquired intangible assets				3,300,000
Yurbuds [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Approximate useful life				7 years
Acquired intangible assets				3,100,000
Yurbuds [Member] | Customer Contracts [Member]
Business Acquisition [Line Items]
Acquisition earn-out contingent payable				800,000
AMX LLC [Member]
Business Acquisition [Line Items]
Purchase price						365,000,000
Acquisition earn-out contingent payable						25,000,000
Number of years expected to occur certain days						36 months
Business acquisition date	Jun. 13, 2014
Goodwill						242,909,000
Goodwill amount deductible for tax purposes						0
Acquisition costs incurred					8,100,000
Cash paid to acquire entity						372,900,000
Acquired intangible assets						101,030,000
Holdback Amounts in escrow						27,000,000
Adjustment resulting in reduction to the purchase price	300,000		300,000			7,900,000
Purchase price inventories	4,200,000		4,200,000			29,100,000
Property, plant and equipment	2,700,000		2,700,000			28,189,000
Fair value amortized estimated lives						4 months
AMX LLC [Member] | Minimum [Member]
Business Acquisition [Line Items]
Fair value amortized estimated lives						5 years
AMX LLC [Member] | Maximum [Member]
Business Acquisition [Line Items]
Fair value amortized estimated lives						35 years
AMX LLC [Member] | Working Capital Holdback [Member]
Business Acquisition [Line Items]
Acquisition earn-out contingent payable						2,000,000
AMX LLC [Member] | Tradenames [Member]
Business Acquisition [Line Items]
Acquired intangible assets						55,700,000
AMX LLC [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired intangible assets						26,700,000
AMX LLC [Member] | Customer Relationships [Member] | Minimum [Member]
Business Acquisition [Line Items]
Approximate useful life						2 years
AMX LLC [Member] | Customer Relationships [Member] | Maximum [Member]
Business Acquisition [Line Items]
Approximate useful life						9 years
AMX LLC [Member] | Technology [Member]
Business Acquisition [Line Items]
Approximate useful life						5 years
Acquired intangible assets						17,000,000
AMX LLC [Member] | Backlog [Member]
Business Acquisition [Line Items]
Approximate useful life						2 months
Acquired intangible assets						1,500,000
AMX LLC [Member] | Covenant Not-to-Compete [Member]
Business Acquisition [Line Items]
Approximate useful life						3 years
Acquired intangible assets						$ 100,000