BENEFIT PLANS, Asset Allocation and Fair Values of Pension Plan Assets (Details) (Pension Plan, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Pension Plan Assets [Abstract]
Weighted average asset allocation (in hundredths)	100.00%		100.00%
Fair value of plan assets	$ 300,457	[1]	$ 273,417	[2]
Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	123,123	[1]	8,444	[2]
Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	177,334	[1]	264,973	[2]
Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	0	[1]	0	[2]
Mutual funds
Pension Plan Assets [Abstract]
Weighted average asset allocation (in hundredths)	39.00%		0.00%
Fair value of plan assets	119,543
Mutual funds | Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	119,543
Mutual funds | Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	0
Mutual funds | Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	0
Fixed income securities
Pension Plan Assets [Abstract]
Weighted average asset allocation (in hundredths)	58.00%		88.00%
Cash equivalents and other
Pension Plan Assets [Abstract]
Weighted average asset allocation (in hundredths)	3.00%		12.00%
Foreign issued corporate debt
Pension Plan Assets [Abstract]
Fair value of plan assets	17,778		26,998
Foreign issued corporate debt | Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
Foreign issued corporate debt | Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	17,778		26,998
Foreign issued corporate debt | Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
U.S. corporate debt
Pension Plan Assets [Abstract]
Fair value of plan assets	50,155		75,068
U.S. corporate debt | Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
U.S. corporate debt | Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	50,155		75,068
U.S. corporate debt | Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
Government debt
Pension Plan Assets [Abstract]
Fair value of plan assets	10,239		11,993
Government debt | Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
Government debt | Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	10,239		11,993
Government debt | Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
U.S. Treasury securities
Pension Plan Assets [Abstract]
Fair value of plan assets	81,552		121,895
U.S. Treasury securities | Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
U.S. Treasury securities | Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	81,552		121,895
U.S. Treasury securities | Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	0		0
Asset-backed securities
Pension Plan Assets [Abstract]
Fair value of plan assets	17,610
Asset-backed securities | Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	0
Asset-backed securities | Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	17,610
Asset-backed securities | Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	0
Cash Equivalents
Pension Plan Assets [Abstract]
Fair value of plan assets	3,580	[3]	37,463	[4]
Cash Equivalents | Level I
Pension Plan Assets [Abstract]
Fair value of plan assets	3,580	[3]	8,444	[4]
Cash Equivalents | Level II
Pension Plan Assets [Abstract]
Fair value of plan assets	0	[3]	29,019	[4]
Cash Equivalents | Level III
Pension Plan Assets [Abstract]
Fair value of plan assets	$ 0	[3]	$ 0	[4]

[1] Excludes cash and net receivables relating to the sale of securities that were not settled as of December 31, 2014.

[2] Excludes net payables relating to the purchase of securities that were not settled as of December 31, 2013.

[3] Represents an investment in a money market fund.

[4] A significant portion represents an investment in a short-term investment fund that invests primarily in securities of high quality and low risk.