EMPLOYEE BENEFIT PLANS - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 371	$ 1,544	$ 742	$ 3,168
Interest cost		830	4,452	1,659	9,135
Expected return on plan assets		(1,007)	(6,330)	(2,014)	(12,988)
Amortization of prior service cost		3	277	6	569
Amortization of losses		916	2,603	1,849	5,340
Amortization of negative plan amendment		0	0	0	0
Net periodic benefit cost	[1]	1,113	2,546	2,242	5,224
Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		3	147	6	326
Interest cost		13	199	26	405
Expected return on plan assets		0	0	0	0
Amortization of prior service cost		0	4	0	8
Amortization of losses		3	116	6	245
Amortization of negative plan amendment		0	(133)	0	(267)
Net periodic benefit cost	[1]	$ 19	333	$ 38	717
Income from Discontinued Operations [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost			$ 2,000		$ 4,000

[1] Net periodic benefit cost for the three and six months ended June 30, 2014 includes $2.0 million and $4.0 million, respectively, recorded in “Income from discontinued operations, net” on the Consolidated Statements of (Loss) Income and Comprehensive (Loss) Income.