EQUITY-BASED COMPENSATION PLANS (NARRATIVE) (DETAILS) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 3,400,000	$ 3,800,000	$ 10,310,000	$ 11,563,000
Requisite Service Period			four or five years
Stock Options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	132,000	2,600	397,000	21,000
Unrecognized Compensation Expense	900,000		900,000
Restricted Stock Units (RSUs) [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	3,300,000	3,800,000	9,900,000	11,500,000
Unrecognized Compensation Expense	28,400,000		28,400,000
Non-option Equity Awards Granted			519,262	611,580
Cost of Services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	500,000		1,500,000
Selling General And Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 2,900,000	$ 3,800,000	$ 8,800,000	$ 11,500,000