Components of Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 1,994,373	$ 1,847,213
Cumulative effect of accounting change	$ (22,462)		(22,462)
Exercise of stock options and release of restricted awards, net of shares withheld for employee taxes			118,545	96,866
Shares repurchased under provisions of stock repurchase plans			(407,932)	(137,960)
Stock compensation expense			29,269	27,826
Net earnings	140,946	$ 108,755	277,146	202,322
Other comprehensive (loss) income	(26,051)	9,236	(17,200)	18,096
Dividends paid			79,180	75,726
Ending Balance	1,892,559	1,978,637	1,892,559	1,978,637
Shareholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			1,991,858	1,844,638
Cumulative effect of accounting change	(22,357)		(22,357)
Exercise of stock options and release of restricted awards, net of shares withheld for employee taxes			118,545	96,866
Shares repurchased under provisions of stock repurchase plans			(407,932)	(137,960)
Stock compensation expense			29,269	27,826
Net earnings			276,297	202,115
Other comprehensive (loss) income			(16,748)	18,085
Dividends paid			79,180	75,726
Ending Balance	1,889,752	1,975,844	1,889,752	1,975,844
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,515	2,575
Cumulative effect of accounting change	(105)		(105)
Net earnings			849	207
Other comprehensive (loss) income			(452)	11
Ending Balance	$ 2,807	$ 2,793	$ 2,807	$ 2,793