Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Income Statement [Abstract]
Net sales	$ 4,232.7	$ 3,917.7	$ 13,177.6	$ 11,977.9
Cost of sales	3,871.5	3,587.5	12,076.8	10,997.6
Selling, general and administrative expenses	128.1	128.6	402.8	386.1
Amortization of intangible assets	8.6	8.6	25.4	25.8
Interest expense	15.7	17.5	47.1	51.6
Other expense, net	11.1	16.8	57.1	37.8
Consolidated income before provision for income taxes and equity in net income of affiliates	197.7	158.7	568.4	479.0
Provision for income taxes	57.6	51.2	163.1	130.2
Equity in net income of affiliates	(7.8)	(9.2)	(29.0)	(27.1)
Consolidated net income	147.9	116.7	434.3	375.9
Less: Net income attributable to noncontrolling interests	7.8	3.9	23.7	17.3
Net income attributable to Lear	140.1	112.8	410.6	358.6
Basic net income per share attributable to Lear	$ 1.75	$ 1.40	$ 5.09	$ 4.14
Diluted net income per share attributable to Lear	$ 1.72	$ 1.38	$ 5.01	$ 4.09
Average common shares outstanding	79,974,811	80,674,338	80,652,376	86,609,304
Average diluted shares outstanding	81,403,225	81,754,163	82,027,127	87,650,438
Consolidated comprehensive income (Note 13)	50.9	148.3	332.2	356.7
Less: Comprehensive income attributable to noncontrolling interests	9.2	4.1	23.0	18.2
Comprehensive income attributable to Lear	$ 41.7	$ 144.2	$ 309.2	$ 338.5