EMPLOYEE BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Contribution Plans
Employer contribution	$ 18.9	$ 15.6	$ 13.3
Pension Plan
Employee Benefit Plans
Expected rate of return on plan assets (as a percent)	8.00%	7.90%
Period of average annual total return used as basis for expected long-term rate of return	20 years
Actual return on plan assets (as a percent)	14.80%	(2.70%)
Pension Plan | Domestic Equity Securities
Employee Benefit Plans
Assumed asset allocations (as a percent)	70.00%
Expected rate of return on plan assets (as a percent)	8.50%
Pension Plan | International Equities
Employee Benefit Plans
Assumed asset allocations (as a percent)	10.00%
Expected rate of return on plan assets (as a percent)	3.30%
Pension Plan | Fixed Income Securities
Employee Benefit Plans
Assumed asset allocations (as a percent)	20.00%
Expected rate of return on plan assets (as a percent)	6.00%