Fair Value Measurements - Additional Information (Detail) - USD ($)			3 Months Ended			6 Months Ended
	Jun. 10, 2015	Feb. 26, 2015	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Apr. 08, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains or losses recognized			$ 0		$ 0	$ 0	$ 0
Red Bend Ltd. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimate fair value of contingent consideration liability		$ 16,700,000	16,700,000			16,700,000
Contingent consideration liability			30,000,000			30,000,000
Duran Audio BV [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimate fair value of contingent consideration liability			1,900,000			1,900,000
Payment towards contingent consideration liability						300,000	$ 300,000
Yurbuds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimate fair value of contingent consideration liability			6,800,000			6,800,000
Symphony Teleca Corporation [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimate fair value of contingent consideration liability			26,200,000			26,200,000
Accretion recorded to increase liability						900,000
Contingent consideration liability								$ 24,900,000
Southern Vision Systems Inc [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimate fair value of contingent consideration liability	$ 0		0			0
Contingent consideration liability			10,000,000			10,000,000
IPSG/VFX [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimate fair value of contingent consideration liability			$ 0	$ 0		$ 0
IPSG/VFX [Member] | Previously Reported [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimate fair value of contingent consideration liability				$ 5,800,000