PER SHARE DATA (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income (Numerator) [Abstract]
Income available to common shareholders	$ 20,755	$ 20,624	$ 41,560	$ 43,490
Income available to common shareholders plus assumed exercise of all outstanding share based awards	$ 20,755	$ 20,624	$ 41,560	$ 43,490
Shares (Denominator) [Abstract]
Income available to common shareholders (in shares)	95,177	94,436	94,886	93,082
Effect of dilutive share-based awards (in shares)	229	105	195	74
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in shares)	95,406	94,541	95,081	93,156
Per share amount [Abstract]
Income available to common shareholders (in dollars per share)	$ 0.22	$ 0.22	$ 0.44	$ 0.47
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in dollars per share)	$ 0.22	$ 0.22	$ 0.44	$ 0.47
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	1,700	2,800	1,900	3,000
Weighted average exercise price of antidilutive securities (in dollars per share)	$ 23.41	$ 20.51	$ 23.39	$ 20.70
Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	4		2