EQUITY-BASED COMPENSATION PLANS (NARRATIVE) (DETAILS) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 3,500,000	$ 4,000,000	$ 6,845,000	$ 7,715,000
Stock Options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	132,000	5,000	264,000	19,000
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	4,000,000	6,600,000	7,700,000
Unrecognized Compensation Expense	32,100,000		32,100,000
Non-option Equity Awards Granted			505,887	568,580
Requisite Service Period			four or five
Cash Based Awards [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	22,000	0	30,000	0
Unrecognized Compensation Expense	400,000		400,000
Non-option Equity Awards Granted			30,000	0
Requisite Service Period			five
Performance Based Restricted Stock Units (PUs) [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	0	0	0	0
Cost of Services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	500,000		1,000,000
Selling General And Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 3,000,000	$ 4,000,000	$ 5,900,000	$ 7,700,000