Consolidated Statement of Changes in Shareholders' Equity (USD $) In Thousands	Total	Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income [Member]	Treasury stock [Member]
Balance at Dec. 31, 2011	$ 3,273,982	$ 122,720	$ 1,001,308	$ 2,429,818	$ 227,659	$ (507,523)
Net earnings	391,240			391,240
Other comprehensive income	67,612				67,612
Issuance of 461, 381 and 2,079 shares for exercise of options, including tax effect in 2014, 2013 and 2012, respectively	59,838	2,079	57,759
Purchase of 4,710, 1,055 and 5,567 common shares in 2014, 2013 and 2012, respectively	(178,669)					(178,669)
Stock-based compensation	7,902	315	7,587
Cash dividends declared, $1.04, $0.78 and $0.64 per share in 2014, 2013 and 2012, respectively	(64,892)			(64,892)
Other	(14,401)		(14,401)
Balance at Dec. 31, 2012	3,542,612	125,114	1,052,253	2,756,166	295,271	(686,192)
Net earnings	407,197			407,197
Other comprehensive income	(176,620)				(176,620)
Issuance of 461, 381 and 2,079 shares for exercise of options, including tax effect in 2014, 2013 and 2012, respectively	12,908	381	12,527
Purchase of 4,710, 1,055 and 5,567 common shares in 2014, 2013 and 2012, respectively	(42,212)					(42,212)
Stock-based compensation	8,407	82	8,325
Cash dividends declared, $1.04, $0.78 and $0.64 per share in 2014, 2013 and 2012, respectively	(77,862)			(77,862)
Other	0		0
Balance at Dec. 31, 2013	3,674,430	125,577	1,073,105	3,085,501	118,651	(728,404)
Net earnings	458,343			458,343
Other comprehensive income	56,363				56,363
Issuance of 461, 381 and 2,079 shares for exercise of options, including tax effect in 2014, 2013 and 2012, respectively	16,798	461	16,337
Issuance of 92 shares for employee stock purchase plan in 2014	3,439	92	3,347
Purchase of 4,710, 1,055 and 5,567 common shares in 2014, 2013 and 2012, respectively	(224,706)					(224,706)
Stock-based compensation	21,104	342	20,762
Cash dividends declared, $1.04, $0.78 and $0.64 per share in 2014, 2013 and 2012, respectively	(102,420)			(102,420)
Other	0		0
Balance at Dec. 31, 2014	$ 3,903,351	$ 126,472	$ 1,113,551	$ 3,441,424	$ 175,014	$ (953,110)