Earnings Per Share - Praxair, Inc. Shareholders (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Antidilutive Securities Excluded From Computation of Earnings Per Share [Abstract]
Antidilutive securities excluded from the computation of Earnings Per Share	1,626,080	1,630,690
NUMERATOR (Millions of dollars) [Abstract]
Net income - Praxair, Inc.	$ 419	$ 398
WEIGHTED AVERAGE SHARES OUTSTANDING (000s):
Weighted average shares outstanding	298,512,000	303,449,000
Shares earned and issuable under compensation plans	565,000	622,000
Weighted average shares used in basic earnings per share	299,077,000	304,071,000
Stock options and awards	3,799,000	4,524,000
Weighted average shares used in diluted earnings per share	302,876,000	308,595,000
Basic Earnings Per Share	$ 1.40	$ 1.31
Diluted Earnings Per Share	$ 1.38	$ 1.29