Consolidated Statement of Changes in Shareholders' Equity (USD $) In Thousands	Total	Common stock [Member]	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income	Treasury stock
Balance at Dec. 31, 2011	$ 3,273,982	$ 122,720	$ 1,001,308	$ 2,429,818	$ 227,659	$ (507,523)
Net earnings	283,139			283,139
Other comprehensive income (loss)	90,580				90,580
Issuance of 1,437 shares for exercise of options, including tax effect	40,105	1,437	38,668
Purchase of 4,543 common shares	(141,535)					(141,535)
Stock-based compensation	6,761	302	6,459
Cash dividends declared $0.475 per share	(48,212)			(48,212)
Balance at Sep. 30, 2012	$ 3,504,820	$ 124,459	$ 1,046,435	$ 2,664,745	$ 318,239	$ (649,058)