Share Based Compensation (Details 1) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y
Data With Respect to Stock Options/SARs Activity
Number of Options, Granted	418
Number of Options, Exercised	(384)
Number of Options, Forfeited/Cancelled	(23)
Number of Options, Expired	(103)
Outstanding Number of Options at end of the year	1,879
Number of Options Vested and exercisable at end of the year	1,120
Outstanding Number of Option at beginning of the year	1,971
Outstanding Weighted Average Price at beginning of the year	$ 30.47
Weighted Average Price of Option Granted	$ 33.94
Weighted Average Price of Option Exercised	$ 28.39
Weighted Average Price of Option Forfeited/Cancelled	$ 28.16
Weighted Average Price of Option Expired	$ 41.70
Outstanding Weighted Average Price at end of the year	$ 31.08
Weighted Average Price of Option Vested and exercisable at end of the year	$ 32.58
Outstanding, Weighted Average Remaining Contractual Term at end of the year	3.7
Weighted Average Remaining Contractual Term of Option Vested and exercisable at end of the year	2.5
Total intrinsic value of options/SARs exercised	$ 4.5
Total Intrinsic Value of Outstanding Option at end of the year	24.2
Total Intrinsic Value of Option, Vested and exercisable at end of the year	$ 13.0