PER SHARE DATA (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Income available to common shareholders	$ 39,528	$ 37,817	$ 115,510	$ 95,058
Income available to common shareholders plus assumed exercise of all outstanding share-based awards	$ 39,528	$ 37,817	$ 115,510	$ 95,058
Income available to common shareholders (in shares)	90,912,000	94,304,000	91,974	94,378
Effect of dilutive share-based awards (in shares)	188,000	260,000	183	239
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in shares)	91,100,000	94,564,000	92,157	94,617
Income available to common shareholders (in dollars per share)	$ 0.43	$ 0.40	$ 1.26	$ 1.01
Income available to common shareholders plus assumed exercise all outstanding share-based awards (in dollars per share)	$ 0.43	$ 0.40	$ 1.25	$ 1.00
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	0	32,400	0	45,000
Weighted average exercise price of antidilutive securities (in dollars per share)		$ 24.47		$ 24.71
Other Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted shares (in shares)	0	0	0	0