EARNINGS PER SHARE (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share Reconciliation [Abstract]
Basic									44,182	44,389	46,624
Dilutive effect of stock options and deferred stock compensation									579	656	992
Diluted									44,761	45,045	47,616
Earnings from continuing operations	$ 1.54	$ 1.45	$ 1.15	$ 0.74	$ 1.60	$ 1.04	$ 0.90	$ 0.74	$ 4.86	$ 4.27	$ 4.12
Earnings from continuing operations	$ 1.52	$ 1.43	$ 1.13	$ 0.73	$ 1.58	$ 1.02	$ 0.88	$ 0.73	$ 4.80	$ 4.20	$ 4.04
Earnings from continuing operations	$ 67,750	$ 63,944	$ 50,650	$ 32,547	$ 70,668	$ 45,932	$ 39,963	$ 32,819	$ 214,891	$ 189,382	$ 192,248