SHARE-BASED COMPENSATION - Performance Share Units Activity (Details) (Performance share units, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2010
Stock Units
Balance, beginning of year	314,000
Granted	344,000	0
Forfeited	(1,000)
Performance adjustment	157,000
Balance, end of year	814,000
Nonvested performance share units that have met the requisite service period and will be released as identified in the grant terms	100,000
Weighted Average Grant Date Fair Value
Balance, beginning of year	$ 27.30
Granted	$ 21.73
Forfeited	$ 27.30
Performance adjustment	$ 24.38
Balance, end of year	$ 24.38
2012 grants
Stock Units
Balance, beginning of year	0
Granted	344,000
Forfeited	0
Performance adjustment	76,000
Balance, end of year	420,000
2011 grants
Stock Units
Balance, beginning of year	314,000
Granted	0
Forfeited	(1,000)
Performance adjustment	81,000
Balance, end of year	394,000