Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive earnings	Treasury stock
Beginning balance (in shares) at Dec. 31, 2014		100,126,000
Beginning balance at Dec. 31, 2014	$ 4,755,360	$ 1,021	$ 1,325,338	$ 3,520,201	$ (71,927)	$ (19,273)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	696,067	$ 0	0	696,067	0	0
Stock option exercises (in shares)		402,000
Stock option exercises	33,006	$ 4	33,002	0	0	0
Treasury stock sold (in shares)		18,000
Treasury stock sold	2,889	$ 0	2,710	0	0	179
Currency translation adjustments, net of tax	(139,789)	0	0	0	(139,789)	0
Stock based compensation	61,766	$ 0	61,766	0	0	0
Restricted stock activity (in shares)		324,000
Restricted stock activity	(14,694)	$ 3	(14,697)	0	0	0
Stock option tax benefit, net of shortfalls	22,175	0	22,175	0	0	0
Conversion of senior subordinated convertible notes	(11,032)	0	(11,032)	0	0	0
Post-retirement benefit plan adjustments	(1,063)	0	0	0	(1,063)	0
Dividends declared	(105,738)	$ 0	0	(105,738)	0	0
Ending balance (in shares) at Dec. 31, 2015		100,870,000
Ending balance at Dec. 31, 2015	5,298,947	$ 1,028	1,419,262	4,110,530	(212,779)	(19,094)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	$ 658,645	$ 0	0	658,645	0	0
Stock option exercises (in shares)	371,853	372,000
Stock option exercises	$ 27,974	$ 4	27,970	0	0	0
Treasury stock sold (in shares)		19,000
Treasury stock sold	3,340	$ 0	3,147	0	0	193
Currency translation adjustments, net of tax	(111,960)	0	0	0	(111,960)	0
Stock based compensation	77,860	$ 0	77,860	0	0	0
Restricted stock activity (in shares)		411,000
Restricted stock activity	(17,976)	$ 4	(17,980)	0	0	0
Stock option tax benefit, net of shortfalls	(8,081)	0	(8,081)	0	0	0
Conversion of senior subordinated convertible notes	(13,111)	0	(13,111)	0	0	0
Post-retirement benefit plan adjustments	0
Dividends declared	$ (126,773)	$ 0	0	(126,773)	0	0
Ending balance (in shares) at Dec. 31, 2016	101,672,000	101,672,000
Ending balance at Dec. 31, 2016	$ 5,788,865	$ 1,036	1,489,067	4,642,402	(324,739)	(18,901)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	$ 971,772	$ 0	0	971,772	0	0
Stock option exercises (in shares)	644,610	645,000
Stock option exercises	$ 61,323	$ 6	61,317	0	0	0
Treasury stock sold (in shares)		20,000
Treasury stock sold	4,198	$ 0	4,003	0	0	195
Currency translation adjustments, net of tax	138,525	0	0	0	138,525	0
Stock based compensation	81,324	$ 0	81,324	0	0	0
Restricted stock activity (in shares)		156,000
Restricted stock activity	(32,840)	$ 2	(32,842)	0	0	0
Post-retirement benefit plan adjustments	0
Dividends declared	$ (149,603)	$ 0	0	(149,603)	0	0
Ending balance (in shares) at Dec. 31, 2017	102,493,000	102,493,000
Ending balance at Dec. 31, 2017	$ 6,863,564	$ 1,044	$ 1,602,869	$ 5,464,571	$ (186,214)	$ (18,706)