PER SHARE DATA (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Income available to common shareholders	$ 37,889	$ 34,692	$ 75,982	$ 57,241
Income available to common shareholders plus assumed exercise of all outstanding share-based awards	$ 37,889	$ 34,692	$ 75,982	$ 57,241
Income available to common shareholders (in shares)	91,366,000	94,461,000	92,505,000	94,415,000
Effect of dilutive share-based awards (in shares)	165,000	234,000	181,000	229,000
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in shares)	91,531,000	94,695,000	92,686,000	94,644,000
Income available to common shareholders (in dollars per share)	$ 0.41	$ 0.37	$ 0.82	$ 0.61
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in dollars per share)	$ 0.41	$ 0.37	$ 0.82	$ 0.60
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)		37,800		51,300
Weighted average exercise price of antidilutive securities (in dollars per share)		$ 24.59		$ 24.78
Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	7,200	14,000	3,600	7,000