STOCK PLANS AND SHARE BASED COMPENSATION (Performance-based Awards and Restricted Stock Units) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Performance Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance-based awards shares released as a percentage of target number, minimum	0.00%
Number of performance-based awards shares released as a percentage of target number, maximum	200.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Outstanding, shares	79,000	99,000	11,000	0
Granted, shares	88,000	101,000	89,000
Vested, shares	(99,000)	(11,000)	0
Forfeited or expired, shares	(9,000)	(2,000)	(78,000)
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 46.25	$ 52.35	$ 0.00
Granted, weighted-average grant date fair value per share	63.99	46.26	52.36
Vested, weighted-average grant date fair value per share	46.25	52.35	0.00
Forfeited or expired, weighted-average grant date fair value per share	63.99	46.87	52.35
Outstanding, weighted-average grant date fair value per share, end of period	$ 63.99	$ 46.25	$ 52.35
Outstanding, weighted-average remaining contractual term (in years)	0 years
Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Outstanding, Aggregate Intrinsic Value	$ 5,819
Outstanding and expected to vest, shares	79,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	0 years
Outstanding and expected to vest, aggregate intrinsic value	$ 5,819
Grant date fair value of awards released	$ 4,600	$ 600
Long-Term Performance-based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance-based awards shares released as a percentage of target number, minimum	0.00%
Number of performance-based awards shares released as a percentage of target number, maximum	200.00%
Performance based period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Outstanding, shares	184,000	150,000	129,000	61,000
Granted, shares	71,000	78,000	72,000
Vested, shares	0	0	0
Forfeited or expired, shares	(37,000)	(57,000)	(4,000)
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 47.65	$ 53.75	$ 55.51
Granted, weighted-average grant date fair value per share	63.00	43.26	52.47
Vested, weighted-average grant date fair value per share	0.00	0.00	0.00
Forfeited or expired, weighted-average grant date fair value per share	51.59	55.35	57.76
Outstanding, weighted-average grant date fair value per share, end of period	$ 52.80	$ 47.65	$ 53.75
Outstanding, weighted-average remaining contractual term (in years)	1 year 5 months 25 days
Outstanding, aggregate intrinsic value	$ 13,547
Outstanding and expected to vest, shares	164,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	1 year 3 months 10 days
Outstanding and expected to vest, aggregate intrinsic value	$ 12,072
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Outstanding, shares	948,000	718,000	681,000	692,000
Granted, shares	558,000	331,000	319,000
Vested, shares	(284,000)	(270,000)	(267,000)
Forfeited or expired, shares	(44,000)	(24,000)	(63,000)
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 47.54	$ 46.98	$ 43.86
Granted, weighted-average grant date fair value per share	60.82	46.70	49.75
Vested, weighted-average grant date fair value per share	46.52	45.13	42.49
Forfeited or expired, weighted-average grant date fair value per share	50.89	47.21	45.71
Outstanding, weighted-average grant date fair value per share, end of period	$ 55.51	$ 47.54	$ 46.98
Outstanding, weighted-average remaining contractual term (in years)	1 year 11 months 20 days
Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Outstanding, Aggregate Intrinsic Value	$ 69,742
Outstanding and expected to vest, shares	860,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	1 year 9 months 20 days
Outstanding and expected to vest, aggregate intrinsic value	$ 63,289
Grant date fair value of awards released	$ 13,200	$ 12,200	$ 11,300