Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive loss	Total shareholders’ equity	Noncontrolling interest
Balance at Dec. 31, 2016	$ 1,847,213	$ 1,799	$ 2,642	$ 1,944,789	$ (104,592)	$ 1,844,638	$ 2,575
Balance (in shares) at Dec. 31, 2016		179,857
Increase (Decrease) in Equity [Roll Forward]
Exercise of stock options and release of restricted shares	176,325	$ 40	176,285			176,325
Exercise of stock options and release of restricted shares (in shares)		4,058
Issuance of shares under stock purchase plan	28,767	$ 7	28,760			28,767
Issuance of shares under stock purchase plan (in shares)		682
Shares repurchased under provisions of stock repurchase plans	(478,258)	$ (82)	(258,049)	(220,127)		(478,258)
Shares repurchased under provisions of stock repurchase plans (in shares)		(8,223)
Stock compensation expense	50,908		50,908			50,908
Net earnings	490,383			489,345		489,345	1,038
Other comprehensive income (loss)	30,434				30,628	30,628	(194)
Dividends paid	(150,495)			(150,495)		(150,495)
Distributions to noncontrolling interest	(904)						(904)
Balance at Dec. 31, 2017	1,994,373	$ 1,764	546	2,063,512	(73,964)	1,991,858	2,515
Balance (in shares) at Dec. 31, 2017		176,374
Increase (Decrease) in Equity [Roll Forward]
Exercise of stock options and release of restricted shares	146,193	$ 36	146,157			146,193
Exercise of stock options and release of restricted shares (in shares)		3,589
Issuance of shares under stock purchase plan	33,291	$ 6	33,285			33,291
Issuance of shares under stock purchase plan (in shares)		666
Shares repurchased under provisions of stock repurchase plans	(647,898)	$ (90)	(234,160)	(413,648)		(647,898)
Shares repurchased under provisions of stock repurchase plans (in shares)		(9,047)
Stock compensation expense	56,147		56,147			56,147
Net earnings	619,790			618,199		618,199	1,591
Other comprehensive income (loss)	(32,390)				(31,517)	(31,517)	(873)
Dividends paid	(156,840)		159	(156,999)		(156,840)
Purchase of noncontrolling interest	(688)		(238)			(238)	(450)
Distributions to noncontrolling interest	(1,796)						(1,796)
Balance at Dec. 31, 2018	$ 1,987,720	$ 1,716	1,896	2,088,707	(105,481)	1,986,838	882
Balance (in shares) at Dec. 31, 2018	171,582	171,582
Increase (Decrease) in Equity [Roll Forward]
Cumulative adjustment for adoption of new accounting pronouncement	$ (22,462)			(22,357)		(22,357)	(105)
Exercise of stock options and release of restricted shares	103,696	$ 28	103,668			103,696
Exercise of stock options and release of restricted shares (in shares)		2,792
Issuance of shares under stock purchase plan	37,875	$ 6	37,869			37,875
Issuance of shares under stock purchase plan (in shares)		585
Shares repurchased under provisions of stock repurchase plans	(389,060)	$ (54)	(202,176)	(186,830)		(389,060)
Shares repurchased under provisions of stock repurchase plans (in shares)		(5,337)
Stock compensation expense	61,543		61,543			61,543
Net earnings	592,016			590,395		590,395	1,621
Other comprehensive income (loss)	(26,018)				(25,706)	(25,706)	(312)
Dividends paid	(170,553)		403	(170,956)		(170,553)
Balance at Dec. 31, 2019	$ 2,197,219	$ 1,696	$ 3,203	$ 2,321,316	$ (131,187)	$ 2,195,028	$ 2,191
Balance (in shares) at Dec. 31, 2019	169,622	169,622