EMPLOYEE COMPENSATION PLANS (NARRATIVE) (DETAILS) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
EMPLOYEE COMPENSATION PLANS [Abstract]
Company Match on US Defined Contribution Plans	$ 4,800,000	$ 4,200,000	$ 3,000,000
Shares Authorized under Current Equity Compensation Plan	4,000,000
Shares Available for Issuance under Current Equity Compensation Plan	1,200,000
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	11,307,000	13,234,000	13,376,000
Total Tax Benefit Recognized for Equity-Based Compensation Expense	6,300,000	5,800,000	5,700,000
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value	$ 26.92	$ 21.66	$ 15.91
Intrinsic Value of RSUs Vested	12,400,000	12,300,000	15,500,000
Intrinsic Value of Non-Vested RSUs	42,400,000
Intrinsic Value of Options Exercised	800,000	1,000,000	600,000
Fair Value of Shares Vested	0	0	0
Proceeds from exercise of stock options	443,000	862,000	1,374,000
Recognized Tax Benefit from Exercise of Stock Options	300,000	400,000	200,000
Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized Compensation Expense	20,000
Requisite Service Period	2 years 1 month 0 days
Stock Option [Member] | Key Employee 1 [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options Granted to Key Employees				150,000
Restricted Stock Units (RSUs) [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized Compensation Expense	27,600,000
Requisite Service Period	1 year 6 months 0 days
Restricted Stock Units (RSUs) [Member] | Key Employee 1 [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options Granted to Key Employees				100,000
Restricted Stock Units (RSUs) [Member] | Key Employee 2 [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options Granted to Key Employees	8,394
Cost of Services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	2,300,000	2,200,000	1,900,000
Selling General And Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 9,000,000	$ 11,100,000	$ 11,500,000