SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES ACCOUNTING FOR STOCK-BASED COMPENSATION (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2011 Market-Based Vesting [Member] Stock Options [Member]	Dec. 31, 2010 Market-Based Vesting [Member] Stock Options [Member] employee	Dec. 31, 2011 Time-based Vesting [Member] Stock Options [Member]	Dec. 31, 2011 Executive Management Staff [Member]	Dec. 31, 2011 Non-employee Director [Member]	Dec. 31, 2011 Other Employees [Member]
Accounting for stock-based compensation [Abstract]
Period of implied volatility of long-term exchange-traded options, minimum (in months)			9
Period of implied volatility of long-term exchange-traded options, maximum (in months)			39
Number of employees affected by modifications in vesting terms of certain outstanding stock options		16
Total incremental compensation charge resulting from plan modifications	$ (0.2)	$ 0.9
Annualized estimated forfeiture rates (in hundredths)				10.00%	0.00%	10.00%