Earnings Per Share (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Treasury stock received from bond hedge, shares																			13,000,000
Companys Weighted Average Share Price Of Bond Hedge																			$ 16.41
Treasury stock issued due to settlement of warrant, shares																			9,800,000
Investment Warrants, Exercise Price																			$ 19.31
Basic earnings per share [Abstract]
Weighted average shares of common stock outstanding																	228,600,000		225,304,000		218,458,000
Earnings per share — basic	$ 0.62		$ 0.73		$ 0.76		$ 0.62		$ 0.52		$ 0.44		$ 0.54		$ 0.73		$ 2.73		$ 2.22		$ 2.52
Diluted earnings per share [Abstract]
Net earnings attributable to BorgWarner Inc.	$ 141.4	[1]	$ 166.8	[1]	$ 174.1	[1]	$ 142.0	[1]	$ 121.2	[1]	$ 101.1	[1]	$ 120.6	[1]	$ 158.0	[1]	$ 624.3		$ 500.9	[1]	$ 550.1
Adjusted for net interest expense on convertible notes																			5.8		21.5
Diluted net earnings attributable to BorgWarner Inc.																	$ 624.3		$ 506.7		$ 571.6
Effect of 3.50% convertible senior notes																			6,644,000		22,778,000
Effect of warrant																			6,800,000		10,430,000
Effect of stock-based compensation																	2,737,000		4,006,000		5,270,000
Total dilutive effect on weighted average shares of common stock outstanding																	2,737,000		17,450,000		38,478,000
Weighted average shares of common stock outstanding including dilutive shares																	231,337,000		242,754,000		256,936,000
Earnings per share — diluted	$ 0.62		$ 0.72		$ 0.75		$ 0.61		$ 0.51		$ 0.43		$ 0.50		$ 0.64		$ 2.70	[2]	$ 2.09	[2]	$ 2.22	[2]
Bond hedge [Member]
Diluted earnings per share [Abstract]
Total anti-dilutive shares																			3,878,000		12,282,000
Convertible Senior Notes Due April 2012 [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Debt instrument stated interest rate									3.50%										3.50%

[1] The Company's results were impacted by the following:•Quarter ended December 31, 2013: The Company incurred restructuring expense of $52.3 million, related to the initiation of Drivetrain segment actions designed to improve future profitability and competitiveness. The Company recorded tax benefits of $7.1 million in connection with the restructuring expense. Additionally, the Company recorded a net tax benefit of $4.4 million related to the reversal of certain state deferred tax asset valuation allowances and other tax adjustments.•Quarter ended September 30, 2013: The Company incurred a net tax benefit of $5.6 million, which was comprised of tax benefits of $3.1 million related to 2012 provision to return adjustments and $2.5 million related to the reversal of certain state deferred tax asset valuation allowances.•Quarter ended March 31, 2013: The Company incurred $11.3 million of expense related to a program termination agreement. Retirement related obligations expense of $5.9 million was primarily related to a first quarter 2013 grant of restricted stock awards to certain retiring NEOs as to which the Company waived the forfeiture provisions. The Company recorded tax benefits of $3.8 million and $2.1 million related to the program termination agreement and retirement related obligations. Additionally, the Company recorded a net tax benefit of $1.7 million, which was comprised of a $6.6 million tax benefit related to the extension of the federal research and development credit and other international tax provisions resulting from the retroactive impact of U.S. legislation enacted in January 2013, partially offset by a $4.9 million tax expense related to a comprehensive income adjustment.•Quarter ended December 31, 2012: Retirement related obligations of $17.3 million are comprised of a $5.7 million loss resulting from the settlement of a portion of the Muncie Plant's pension obligation and an $11.6 million expense associated with the retirement of certain NEOs. These obligations were partially offset by a $6.1 million tax benefit. The Company incurred tax expense of $3.9 million which included $11.1 million of U.S. tax expense to correct the income taxes payable balance, partially offset by tax benefits resulting from changes to the statutory income tax rate in certain countries and the settlement of certain tax audits. •Quarter ended September 30, 2012: The Company incurred $1.8 million of expense and $11.2 million of tax expense associated with the completion of the sale of its spark plug business. The Company also recorded restructuring expense of $27.4 million primarily associated with the disposal and future requirements of BERU's on-going business, which was partially offset by a tax benefit of $7.7 million. Additionally, the Company incurred tax expense of $6.9 million primarily resulting from the settlement of certain tax audits.•Quarter ended June 30, 2012: The Company recorded expense of $37.9 million primarily due to the write-down of prior purchase price accounting adjustments included within the disposal group as a result of signing a Master Purchase Agreement to sell the spark plug business to Federal-Mogul Corporation, which was partially offset by a tax benefit of $5.5 million resulting from the write-down. Additionally, the Company recorded tax expense of $9.0 million related to its decision to change its cash repatriation assertion for some of its foreign subsidiaries.

[2] * The Company's diluted earnings per share for the years ended December 31, 2012 and 2011 includes the impact of the Company's 3.50% convertible senior notes and associated warrants. Refer to Note 16, "Earnings Per Share," for further information on the diluted earnings per share calculation.