RETIREMENT ANNUITY AND GUARANTEED CONTINUOUS EMPLOYMENT PLANS (Defined Contribution Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Contribution Plan
Minimum percentage of eligible compensation that may be invested by all U.S. employees covered under the plan (as a percent)	1.00%
Employer match of employee contributions of first 6% of eligible compensation (as a percent)	35.00%
Percentage of eligible compensation, matched 35% by employer (as a percent)	6.00%
Percentage of base pay as additional annual Company contribution to participants hired after November 1, 1997 (as a percent)	2.00%
Annual costs recognized for defined contribution plans	$ 10,082	$ 11,088	$ 10,812
Minimum
Defined Contribution Plan
Percentage of base pay as additional annual Company contribution to participants hired after November 1, 1997 (as a percent)	4.00%
Maximum
Defined Contribution Plan
Percentage of base pay as additional annual Company contribution to participants hired after November 1, 1997 (as a percent)	10.00%