EMPLOYEE BENEFIT PLANS - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 371	$ 378	$ 1,113	$ 3,545
Interest cost		830	786	2,489	9,921
Expected return on plan assets		(1,007)	(1,135)	(3,020)	(14,123)
Amortization of prior service cost		3	3	10	572
Amortization of losses		950	601	2,799	5,942
Amortization of negative plan amendment				0	0
Net periodic benefit cost	[1]	1,147	633	3,391	5,857
Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		3	3	8	328
Interest cost		13	18	39	423
Expected return on plan assets		0	0	0	0
Amortization of prior service cost		0	0	0	8
Amortization of losses		3	3	9	248
Amortization of negative plan amendment				0	(267)
Net periodic benefit cost	[1]	$ 19	$ 24	$ 56	740
Income from Discontinued Operations [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost					$ 4,000

[1] Net periodic benefit cost for the nine months ended September 30, 2014 includes $4.0 million recorded in “Income from discontinued operations, net” on the Consolidated Statements of Income and Comprehensive Income.