EMPLOYEE COMPENSATION PLANS (NARRATIVE) (DETAILS) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended				36 Months Ended
	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Company Match on US Defined Contribution Plans		$ 5,200	$ 4,800	$ 4,200
Shares Authorized under Current Equity Compensation Plan		4,000,000				4,000,000
Shares Available for Issuance under Current Equity Compensation Plan		1,000,000				1,000,000
Exercise of stock options, share		(894,168)
Equity-based compensation expense		$ 11,304	11,307	13,234
Total Tax Benefit Recognized for Equity-Based Compensation Expense		$ 6,700	6,300	5,800
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value		$ 26.52
Intrinsic Value of Non-Vested RSUs		$ 43,400				$ 43,400
Intrinsic Value of Options Exercised		13,894
Fair Value of Shares Vested						0
Proceeds from exercise of stock options		825	443	862
Recognized Tax Benefit from Exercise of Stock Options		1,000	300	400
Chief Financial Officer [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options Granted to Key Employees					150,000
Stock Options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized Compensation Expense		$ 300				300
Requisite Service Period		2 years 7 months 6 days
Intrinsic Value of Options Exercised		$ 13,900	$ 800	$ 1,000
Stock Options [Member] | Chief Executive Officer [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Exercise of stock options, share	800,000
Option Indexed to Issuer's Equity, Strike Price	$ 11.35
Share-based Compensation Arrangement by Share-based Payment Award, Description	To effectuate a "cashless exercise" of the option, on August 24, 2015, Mr. Tuchman entered into a Stock Purchase Agreement with TeleTech, under the terms of which he exercised the option at the end of business on August 31, 2015 and, upon issuance of the option shares, sold to TeleTech, in a simultaneous transaction, a number of shares necessary to pay the option exercise price plus any tax withholding obligations. The option shares were valued at the market price of the close of business on that date. Mr. Tuchman's option, granted under TeleTech's 1999 Stock Option and Incentive Plan, was fully vested and set to expire in November, 2015, The Stock Purchase Agreement was approved by the independent members of TeleTech's Board of Directors who deemed it to be in the best interest of the Company and all its shareholders.
Stock Options [Member] | Key Employee1 [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		$ 28,600				$ 28,600
Requisite Service Period		1 year 7 months 6 days
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value		$ 26.52	$ 26.92	$ 21.66
Intrinsic Value of RSUs Vested		$ 13,000	$ 12,400	$ 12,300
Restricted Stock Units (RSUs) [Member] | Chief Financial Officer [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] | Executive Officer [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Options Granted to Key Employees		8,394
Restricted Stock Units (RSUs) [Member] | Executive Vice President [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense		$ 400
Cost of Services
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense		2,900	2,300	2,200
Selling General And Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense		$ 8,400	$ 9,000	$ 11,100