Goodwill and Intangible Assets, Net - Additional Information (Detail) € in Millions		1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 22, 2016 EUR (€) Installment	Jul. 31, 2016 EUR (€)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) Unit	Dec. 31, 2015 USD ($)	Jun. 30, 2016 USD ($)	Mar. 10, 2016 USD ($)
Goodwill [Line Items]
Goodwill			$ 1,500,499,000		$ 1,500,499,000		$ 1,510,279,000
Goodwill, unfavorable foreign currency translation					9,700,000
Goodwill impairment charges			0	$ 0	0	$ 0
Net intangible assets			435,930,000		435,930,000		476,284,000
Amortization expense of intangible assets			15,200,000	$ 23,000,000	30,700,000	$ 44,100,000
Lifestyle Audio [Member]
Goodwill [Line Items]
Goodwill			$ 155,972,000		$ 155,972,000		157,600,000
Number of reporting units | Unit					2
TowerSec Ltd. [Member]
Goodwill [Line Items]
Goodwill								$ 69,438,000
Increase (Decrease) in goodwill					$ (100,000)
Innovative Systems GmbH [Member]
Goodwill [Line Items]
Loss contingency settlement agreement date					Jun. 22, 2016
Percentage of shareholders involved in contingent purchase Price	80.05%
Loss contingency settlement agreement terms					Under the terms of the agreement, we will pay the 80.05% Shareholders €76.8 million (the “IS Obligation”), with an initial payment of €24.8 million which was paid in July 2016 and four installment payments of €13 million due every July 1st from 2017 through 2020.
Remaining disputed amount | €	€ 76.8
Remaining disputed amount, initial payment paid | €		€ 24.8
Number of installments after initial payment | Installment	4
Remaining disputed amount, each installment payable | €	€ 13.0
First installment due date					Jul. 01, 2017
Final installment due date					Jul. 01, 2020
Additional contingent purchase price							$ 74,500,000
Discount percentage on early installments	8.00%						8.00%
Disputes resolved shareholders percentage	19.95%