BENEFIT PLANS (Combined Funded Status of Plans and their Reconciliation with Related Amounts Recognized in Consolidated Financial Statements) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Change in Benefit Obligation
Projected benefit obligation at beginning of year	$ 991,338,000		$ 867,374,000
Service cost	21,904,000		22,349,000
Interest cost	40,995,000		43,194,000
Plan amendments	(39,443,000)	[1],[2]	1,286,000	[1],[2]
Actuarial loss	(61,548,000)		96,222,000
Benefits paid	(41,546,000)		(39,087,000)
Projected benefit obligation at end of year	911,700,000		991,338,000		867,374,000
Change in Plan Assets
Fair value of assets at beginning of year	683,091,000		636,648,000
Actual return on plan assets	110,224,000		81,021,000
Employer contribution	4,855,000		4,509,000		4,906,000
Fair value of assets at end of year	756,624,000		683,091,000		636,648,000
Funded status	(155,076,000)		(308,247,000)
Amounts Recognized in the Consolidated Balance Sheets
Noncurrent assets	3,056,000		0
Current liabilities	(11,398,000)		(5,211,000)
Noncurrent liabilities	(146,734,000)		(303,036,000)
Net amount recognized	(155,076,000)		(308,247,000)
Amounts Recognized in Accumulated Other Comprehensive Income
Net actuarial loss	142,173,000		325,807,000
Prior service cost	(168,000)		1,609,000
Total amount recognized	142,005,000		327,416,000
Pension Plans, Defined Benefit
Change in Benefit Obligation
Service cost	21,904,000		22,349,000		20,762,000
Interest cost	40,995,000		43,194,000		42,383,000
Change in Plan Assets
Fair value of assets at beginning of year	683,091,000
Employer contribution	0		0		0
Fair value of assets at end of year	756,624,000		683,091,000
Other Postretirement Benefit Plans, Defined Benefit
Change in Benefit Obligation
Projected benefit obligation at beginning of year	113,500,000		134,926,000
Service cost	2,830,000		4,409,000		4,789,000
Interest cost	3,260,000		5,851,000		6,450,000
Plan amendments	0		(38,414,000)
Actuarial loss	(20,444,000)		13,562,000
Benefits paid	(6,258,000)		(6,834,000)		(7,176,000)
Projected benefit obligation at end of year	92,888,000		113,500,000		134,926,000
Change in Plan Assets
Fair value of assets at beginning of year	0		0
Actual return on plan assets	0		0
Fair value of assets at end of year	0		0		0
Funded status	(92,888,000)		(113,500,000)
Amounts Recognized in the Consolidated Balance Sheets
Current liabilities	(9,431,000)		(10,366,000)
Noncurrent liabilities	(83,457,000)		(103,134,000)
Net amount recognized	(92,888,000)		(113,500,000)
Amounts Recognized in Accumulated Other Comprehensive Income
Net actuarial loss	16,405,000		38,221,000
Prior service cost	(36,319,000)		(41,182,000)
Total amount recognized	$ (19,914,000)		$ (2,961,000)

[1] The 2013 amendment eliminated future accruals for salaried pension participants effective December 31, 2013.

[2] The 2012 amendment to the salaried plan was necessary to maintain compliance with IRS nondiscrimination requirements.