EARNINGS PER SHARE (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share Reconciliation [Abstract]
Basic									42,739	43,892	44,182
Dilutive effect of stock options and deferred stock compensation									277	424	579
Diluted									43,016	44,316	44,761
Net earnings	$ 89,408	$ 82,510	$ 80,072	$ 55,593	$ 82,835	$ 74,483	$ 74,788	$ 43,643	$ 307,583	$ 275,749	$ 214,891
Diluted earnings per share	$ 2.08	$ 1.92	$ 1.86	$ 1.29	$ 1.89	$ 1.68	$ 1.68	$ 0.98	$ 7.15	$ 6.22	$ 4.80
Basic earnings per share	$ 2.09	$ 1.93	$ 1.87	$ 1.30	$ 1.91	$ 1.70	$ 1.69	$ 0.99	$ 7.20	$ 6.28	$ 4.86