Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Earnings [Member]	Treasury Stock [Member]	Total
Beginning Balance at Dec. 31, 2012	$ 1,006	$ 1,158,001	$ 2,489,858	$ 58,537	$ (19,676)	$ 3,687,726
Beginning Balance (in shares) at Dec. 31, 2012	98,604,000
Net earnings	$ 0	0	538,293	0	0	538,293
Stock option exercises	$ 4	23,995	0	0	0	23,999
Stock option exercises (in shares)	434
Treasury stock sold	$ 0	2,248	0	0	201	2,449
Treasury stock sold (in shares)	20
Currency translation adjustments, net of tax	$ 0	0	0	(15,454)	0	(15,454)
Stock based compensation	0	53,417	0	0	0	53,417
Restricted stock activity	$ 3	(16,046)	0	0	0	(16,043)
Restricted stock activity (in shares)	254
Stock option tax benefit, net of shortfalls	$ 0	16,000	0	0	0	16,000
Conversion of senior subordinated convertible notes	$ 0	(8,382)	0	0	0	(8,382)
Conversion of senior subordinated convertible notes (in shares)	0
Dividends declared	$ 0	0	(68,955)	0	0	(68,955)
Ending Balance at Dec. 31, 2013	1,013	1,229,233	2,959,196	43,083	(19,475)	$ 4,213,050
Ending Balance (in shares) at Dec. 31, 2013						99,312
Net earnings	0	0	646,033	0	0	$ 646,033
Stock option exercises	$ 6	32,517	0	0	0	32,523
Stock option exercises (in shares)	581
Treasury stock sold	$ 0	2,549	0	0	202	2,751
Treasury stock sold (in shares)	20
Currency translation adjustments, net of tax	$ 0	0	0	(115,010)	0	(115,010)
Stock based compensation	0	63,025	0	0	0	63,025
Restricted stock activity	$ 2	(22,064)	0	0	0	(22,062)
Restricted stock activity (in shares)	213
Stock option tax benefit, net of shortfalls	$ 0	21,481	0	0	0	21,481
Conversion of senior subordinated convertible notes	$ 0	(1,403)	0	0	0	(1,403)
Conversion of senior subordinated convertible notes (in shares)	0
Dividends declared	$ 0	0	(85,028)	0	0	(85,028)
Ending Balance at Dec. 31, 2014	1,021	1,325,338	3,520,201	(71,927)	(19,273)	$ 4,755,360
Ending Balance (in shares) at Dec. 31, 2014						100,126
Net earnings	0	0	696,067	0	0	$ 696,067
Stock option exercises	$ 4	33,002	0	0	0	33,006
Stock option exercises (in shares)	402
Treasury stock sold	$ 0	2,710	0	0	179	2,889
Treasury stock sold (in shares)	18
Currency translation adjustments, net of tax	$ 0	0	0	(139,789)	0	(139,789)
Stock based compensation	0	61,766	0	0	0	61,766
Restricted stock activity	$ 3	(14,697)	0	0	0	(14,694)
Restricted stock activity (in shares)	324
Stock option tax benefit, net of shortfalls	$ 0	22,175	0	0	0	22,175
Conversion of senior subordinated convertible notes	0	(11,032)	0	0	0	$ (11,032)
Conversion of senior subordinated convertible notes (in shares)						0
Deferred Pension Gain	0	0	0	(1,063)	0	$ (1,063)
Dividends declared	0	0	(105,738)	0	0	(105,738)
Ending Balance at Dec. 31, 2015	$ 1,028	$ 1,419,262	$ 4,110,530	$ (212,779)	$ (19,094)	$ 5,298,947
Ending Balance (in shares) at Dec. 31, 2015						100,870