EMPLOYEE BENEFIT PLANS - Net Periodic Benefit Cost (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 371		$ 1,624
Interest cost	830		4,683
Expected return on plan assets	(1,007)		(6,658)
Amortization of prior service cost	3		292
Amortization of losses	933		2,737
Amortization of negative plan amendment	0		0
Net periodic benefit cost	1,130	[1]	2,678	[1]
Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3		179
Interest cost	13		206
Expected return on plan assets	0		0
Amortization of prior service cost	0		4
Amortization of losses	3		129
Amortization of negative plan amendment	0		(134)
Net periodic benefit cost	19	[1]	384	[1]
Income from Discontinued Operations [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost			$ 2,000

[1] Net periodic benefit cost for the three months ended March 31, 2014 includes $2.0 million recorded in “Income from discontinued operations, net” on the Consolidated Statements of Income and Comprehensive Income.