Entity Information (USD $) In Billions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Jun. 30, 2011
Entity Information [Abstract]
Trading Symbol	PX
Entity Registrant Name	PRAXAIR INC
Entity Central Index Key	0000884905
Entity Well Known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	298,689,341
Entity Public Float		$ 33