Condensed 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, 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
Increase (Decrease) in Equity [Roll Forward]
Shares issued under employee stock plans	27,190	$ 6	27,184			27,190
Shares issued under employee stock plans (in shares)		654
Shares repurchased under provisions of stock repurchase plan	(44,334)	$ (6)	(38,484)	(5,844)		(44,334)
Shares repurchased under provisions of stock repurchase plans (in shares)		(588)
Stock compensation expense	13,382		13,382			13,382
Net earnings	140,111			139,699		139,699	412
Other comprehensive income (loss)	1,365				1,495	1,495	(130)
Balance at Mar. 31, 2019	2,125,434	$ 1,716	3,978	2,222,562	(103,986)	2,124,270	1,164
Balance (in shares) at Mar. 31, 2019		171,648
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
Increase (Decrease) in Equity [Roll Forward]
Shares issued under employee stock plans	$ 22,003	$ 6	21,997			22,003
Shares issued under employee stock plans (in shares)		571
Shares repurchased under provisions of stock repurchase plan	(283,240)	$ (40)	(35,799)	(247,401)		(283,240)
Shares repurchased under provisions of stock repurchase plans (in shares)		(4,000)
Stock compensation expense	11,156		11,156			11,156
Net earnings	122,782			122,344		122,344	438
Other comprehensive income (loss)	(38,849)				(38,559)	(38,559)	(290)
Dividends paid			125	(125)
Balance at Mar. 31, 2020	$ 2,037,145	$ 1,662	$ 682	2,202,208	$ (169,746)	2,034,806	$ 2,339
Balance (in shares) at Mar. 31, 2020	166,193	166,193
Increase (Decrease) in Equity [Roll Forward]
Cumulative effect of accounting change	$ 6,074			$ 6,074		$ 6,074