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Summary of Significant Accounting Policies and Basis of Presentation - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017 USD ($) Customer	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Accounting Policies [Line Items]
Amount reclassified from prepaid expenses and other assets to other non-current assets		$ 4,390,000
Cash and cash equivalents	$ 103,172,000	177,187,000	$ 144,479,000	$ 85,700,000
Depreciation expense	32,224,000	24,873,000	18,399,000
Impairment of goodwill	0	0	0
Share based compensation expense	12,727,000	8,147,000	12,316,000
Related deferred tax benefit	3,955,000	4,508,000
Stock options outstanding under the 1993,1997, 2006 and 2011 Stock Option Plans
Accounting Policies [Line Items]
Related deferred tax benefit	4,339,000	2,891,000	3,787,000
Production tooling
Accounting Policies [Line Items]
Reimbursable tooling capitalized within prepaid expenses and other current assets	$ 6,994,000	5,604,000
Minimum
Accounting Policies [Line Items]
Payment terms of contracts	30 days
Minimum | Production tooling
Accounting Policies [Line Items]
Property plant and equipment, estimated useful life	2 years
Maximum
Accounting Policies [Line Items]
Payment terms of contracts	120 days
Maximum | Production tooling
Accounting Policies [Line Items]
Property plant and equipment, estimated useful life	7 years
Patents
Accounting Policies [Line Items]
Amortization of intangibles	$ 12,425,000	$ 12,675,000	$ 12,751,000
Concentration of Credit Risk | Accounts receivable | Lear
Accounting Policies [Line Items]
Concentration risk percentage	24.00%	25.00%
Concentration of Credit Risk | Accounts receivable | Adient
Accounting Policies [Line Items]
Concentration risk percentage	20.00%	24.00%
Concentration of Credit Risk | Accounts receivable | Magna
Accounting Policies [Line Items]
Concentration risk percentage	7.00%
Concentration of Credit Risk | Accounts receivable | Faurecia
Accounting Policies [Line Items]
Concentration risk percentage		7.00%
Customer Concentration Risk | Sales Revenue
Accounting Policies [Line Items]
Number of largest customer | Customer	3
Customer Concentration Risk | Sales Revenue | Lear
Accounting Policies [Line Items]
Concentration risk percentage	20.00%	21.00%	22.00%
Revenues from sales	$ 192,756,000
Customer Concentration Risk | Sales Revenue | Adient
Accounting Policies [Line Items]
Concentration risk percentage	18.00%	21.00%	23.00%
Revenues from sales	$ 173,964,000
Customer Concentration Risk | Sales Revenue | Bosch
Accounting Policies [Line Items]
Concentration risk percentage	8.00%	8.00%	9.00%
Revenues from sales	$ 75,370,000
Foreign Jurisdictions
Accounting Policies [Line Items]
Cash and cash equivalents	$ 88,440,000	$ 162,881,000

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