PER SHARE DATA (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	12,000		6,000
Income (Numerator) [Abstract]
Income available to common shareholders	$ 39,713	$ 30,868	$ 71,979	$ 59,312
Income available to common shareholders plus assumed exercise of all outstanding share based awards	$ 39,713	$ 30,868	$ 71,979	$ 59,312
Shares (Denominator) [Abstract]
Income available to common shareholders (in shares)	96,626,000	96,034,000	96,493,000	95,832,000
Effect of dilutive share-based awards (in shares)	332,000	339,000	329,000	331,000
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in shares)	96,958,000	96,373,000	96,822,000	96,163,000
Per share amount [Abstract]
Income available to common shareholders (in dollars per share)	$ 0.41	$ 0.32	$ 0.75	$ 0.62
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in dollars per share)	$ 0.41	$ 0.32	$ 0.74	$ 0.62
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)		414,000	32,400	69,000
Weighted average exercise price of antidilutive securities (in dollars per share)		$ 24.32	$ 25.31	$ 24.89
Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)		10,000		5,000