BorgWarner Inc. and Consolidated Subsidiaries Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Capital stock:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, authorized	5,000,000	5,000,000
Preferred stock, issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	390,000,000	390,000,000
Common stock, issued	121,315,705	120,086,206
Common stock, outstanding	108,514,462	112,316,444
Treasury stock, shares	12,801,243	7,769,762
Nonvoting Common Stock [Member]
Capital stock:
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	25,000,000	25,000,000
Common stock, issued	0	0
Common stock, outstanding	0	0