Consolidated Statements of Total Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Total Shareholders' Equity	Noncontrolling Interests
Beginning Balance at Dec. 31, 2016	$ 4,142,590	$ 630	$ 3,334,461	$ (130,687)	$ 935,574	$ 4,139,978	$ 2,612
Beginning Balance (in shares) at Dec. 31, 2016		63,176
Consolidated net earnings	336,087				336,159	336,159	(72)
Other comprehensive earnings, net of tax	7,769			7,759		7,759	10
Dividends declared	(80,961)				(80,961)	(80,961)
Issuances of common stock for stock award plans	14,800	$ 2	14,798			14,800
Issuances of common stock for stock award plans (in shares)		141
Shares withheld for employees' income tax obligations	(10,213)		(10,213)			(10,213)
Repurchases of common stock	(99,999)	$ (5)			(99,994)	(99,999)
Repurchases of common stock, (in shares)		(458)
Stock-based compensation expense	23,698		23,698			23,698
Contributions by owners of noncontrolling interest	211						211
Ending Balance at Sep. 30, 2017	4,333,982	$ 627	3,362,744	(122,928)	1,090,778	4,331,221	2,761
Ending Balance (in shares) at Sep. 30, 2017		62,859
Beginning Balance at Jun. 30, 2017				(125,906)
Consolidated net earnings	151,539
Ending Balance at Sep. 30, 2017	4,333,982	$ 627	3,362,744	(122,928)	1,090,778	4,331,221	2,761
Ending Balance (in shares) at Sep. 30, 2017		62,859
Beginning Balance at Dec. 31, 2017	4,682,477	$ 628	3,368,007	(129,104)	1,440,069	4,679,600	2,877
Beginning Balance (in shares) at Dec. 31, 2017		62,873
Consolidated net earnings	375,896				375,621	375,621	275
Other comprehensive earnings, net of tax	7,614			7,613		7,613	1
Dividends declared	(86,190)				(86,190)	(86,190)
Issuances of common stock for stock award plans	14,039	$ 1	14,038			14,039
Issuances of common stock for stock award plans (in shares)		144
Shares withheld for employees' income tax obligations	(10,416)		(10,416)			(10,416)
Repurchases of common stock	(60,377)	$ (3)			(60,374)	(60,377)
Repurchases of common stock, (in shares)		(305)
Stock-based compensation expense	23,084		23,084			23,084
Noncontrolling interest acquired in business combination	9,001						9,001
Purchase of remaining interest in existing joint venture	(12,800)		(3,580)			(3,580)	(9,220)
Ending Balance at Sep. 30, 2018	4,942,328	$ 626	3,391,133	(121,491)	1,669,126	4,939,394	2,934
Ending Balance (in shares) at Sep. 30, 2018		62,712
Beginning Balance at Jun. 30, 2018				(125,883)
Consolidated net earnings	180,353
Ending Balance at Sep. 30, 2018	$ 4,942,328	$ 626	$ 3,391,133	$ (121,491)	$ 1,669,126	$ 4,939,394	$ 2,934
Ending Balance (in shares) at Sep. 30, 2018		62,712