Components of Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 1,847,213	$ 1,694,676
Exercise of stock options			96,866	90,123
Shares repurchased under provisions of stock repurchase plans			(137,960)	(166,407)
Stock compensation expense			27,826	23,788
Tax benefits from stock plans, net				(2,444)
Net earnings	$ 108,755	$ 116,439	202,322	213,486
Other comprehensive income (loss)	9,236	(10,297)	18,096	(717)
Dividends paid			75,726	73,000
Ending Balance	1,978,637	1,779,505	1,978,637	1,779,505
Shareholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			1,844,638	1,691,993
Exercise of stock options			96,866	90,123
Shares repurchased under provisions of stock repurchase plans			(137,960)	(166,407)
Stock compensation expense			27,826	23,788
Tax benefits from stock plans, net				(2,444)
Net earnings			202,115	212,636
Other comprehensive income (loss)			18,085	(774)
Dividends paid			75,726	73,000
Ending Balance	1,975,844	1,775,915	1,975,844	1,775,915
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,575	2,683
Net earnings			207	850
Other comprehensive income (loss)			11	57
Ending Balance	$ 2,793	$ 3,590	$ 2,793	$ 3,590