EARNINGS PER SHARE AND DIVIDEND DATA (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income (Numerator) [Abstract]
Income available to common shareholders	$ 37,569	$ 22,942	$ 82,729
Effect of dilutive stock options	0	0	0
Income available to common shareholders plus assumed exercise	$ 37,569	$ 22,942	$ 82,729
Shares (Denominator) [Abstract]
Income available to common shareholders (in shares)	83,486,000	83,425,000	83,295,000
Effect of dilutive stock options (in shares)	23,000	90,000	135,000
Income available to common shareholders plus assumed exercise (in shares)	83,509,000	83,515,000	83,430,000
Per share amount [Abstract]
Income available to common shareholders (in dollars per share)	$ 0.45	$ 0.28	$ 0.99
Income available to common shareholders plus assumed exercise of (in dollars per share)	$ 0.45	$ 0.27	$ 0.99
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	2,800,000	2,200,000	1,200,000
Weighted average exercise price of antidilutive securities (in dollars per share)	$ 21.75	$ 23.46	$ 23.98
Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	36,000		23,000