ACCUMULATED OTHER COMPREHENSIVE INCOME LOSS ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Reclass) (Details) - USD ($) $ 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
Accumulated Other Comprehensive Income (Loss) [Line Items]
Earnings before income taxes										$ 299,619	$ 267,961	$ 275,194
Provision for income taxes										(84,728)	(78,579)	(82,946)
Net earnings		$ 67,750	$ 63,944	$ 50,650	$ 32,547	$ 68,615	$ 45,932	$ 39,963	$ 32,819	214,891	187,329	$ 145,461
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	[1]									756	703
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	[1]									(12,702)	(11,733)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Curtailments, before Tax										(327)	0
Earnings before income taxes										(12,273)	(11,030)
Provision for income taxes										4,468	4,126
Net earnings										$ (7,805)	$ (6,904)

[1] These items are included in the computation of net periodic pension cost. See Note 15, Pension and Other Postretirement Benefit Plans.