Supplemental Guarantor Condensed Consolidating Financial Statements - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014 8.125% Senior Notes due 2020	Dec. 31, 2013 8.125% Senior Notes due 2020	Sep. 27, 2014 4.75% Senior Notes due 2023	Dec. 31, 2013 4.75% Senior Notes due 2023	Sep. 27, 2014 5.375% Senior Notes due 2024
Condensed Financial Statements, Captions [Line Items]
Long-term debt, aggregate principal amount					$ 245,000,000		$ 500,000,000		$ 325,000,000
Long-term debt, stated coupon rate					8.125%	8.125%	4.75%	4.75%	5.375%
Long-term debt, maturity date					Mar. 15, 2020	Mar. 15, 2020	Jan. 15, 2023	Jan. 15, 2023
Long-term debt, maturity year									2024
Selling, general and administrative expenses allocated from Lear	$ 30,700,000	$ 31,700,000	$ 90,500,000	$ 93,300,000