Share-Based Compensation (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 number	Mar. 31, 2011 number	Jun. 30, 2012 Subsequent Event Restricted Stock Grant Member	Mar. 31, 2012 Stock Options	Mar. 31, 2012 Performance - Based Awards	Mar. 31, 2011 Performance - Based Awards	Mar. 31, 2012 Restricted Stock Awards
Additional Company Information [Abstract]
Share-based compensation expense - gross	$ 17,000,000	$ 14,000,000
Share-based compensation expense net of tax	11,000,000	10,000,000
Praxair, Inc. closing stock price	115
Aggregate Intrinsic Value [Abstract]
Outstanding at March 31, 2012 intrinsic value	596,000,000
Exercisable March 31, 2012 intrinsic value	553,000,000
Average Exercise Price [Abstract]
Outstanding at January 1, 2012 average exercise price	$ 65.30
Granted - average exercise price	$ 110
Exercised average exercise price	$ 53.00
Cancelled or Expired average exercise price	$ 99.26
Outstanding at March 31, 2012 average exercise price	$ 71.65
Exercisable at March 31, 2012 average exercise price	$ 63.06
Average Remaining Life (years) [Abstract]
Outstanding at March 31, 2012 average remaining life	6.0
Exercisable at March 31, 2012 average remaining life	5.1
Black Scholes Option Pricing model assumptions [Abstract]
Dividend yield	2.00%	2.00%
Volatility	22.50%	22.30%
Risk-free interest rate	0.86%	2.20%
Expected term (years)	5	5
Number of Options (000s) [Abstract]
Stock Options Outstanding at January 1, 2012	13,540
Stock Options Granted	1,635
Stock Options Exercised During Period	(1,294)
Stock Options Cancelled or Expired	(11)
Stock Options Outstanding at March 31, 2012	13,870
Stock Options Exercisable at March 31, 2012	10,722
Share Based Compenation Additional Information [Abstract]
Unrecognized compensation expense				44,000,000	51,000,000		10,000,000
Recognition period remaining				1.2
Performance based awards vesting, as a percentage of the target, low end of range					0.00%
Performance based awards vesting, as a percentage of the target, high end of range					150.00%
Non-vested at January 1, 2012					962		340
Granted			89		401
Vested					(507)		(87)
Cancelled					(2)		(7)
Non-vested at March 31, 2012					854		246
Non-vested at January 1, 2012					$ 71.58		$ 75.51
Granted average grant date fair value			$ 109		$ 103	$ 92.06
Vested average grant date fair value					$ 56.30		$ 61.20
Cancelled average grant date fair value					$ 89.37		$ 75.82
Non-vested at March 31, 2012					$ 88.86		$ 80.61
Performance Period					3 Years		3 Years
Share Based Compensation Cost Recognition Period					through the first quarter of 2015		through the first quarter of 2017
Stock Options Additional Information [Abstract]
Weighted-average fair values of options granted	$ 17.46	$ 17.70
Total intrinsic value of stock options exercised	74,000,000	69,000,000
Cash received from option exercises	69,000,000	73,000,000
Excess tax benefit on stock option exercises	32,000,000	18,000,000
Cash tax benefit realized from stock option exercises	$ 46,000,000	$ 24,000,000