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, 2013	$ 3,674,430	$ 125,577	$ 1,073,105	$ 3,085,501	$ 118,651	$ (728,404)
Net earnings	205,047			205,047
Other comprehensive income	101,771				101,771
Issuance of 301 shares for exercise of options, including tax effect	10,087	301	9,786
Issuance of 44 shares for employee stock purchase plan	1,622	44	1,578
Purchase of 961 common shares	(41,542)					(41,542)
Stock-based compensation	7,634	330	7,304
Cash dividends declared, $0.45 per share	(44,994)			(44,994)
Balance at Jun. 30, 2014	$ 3,914,055	$ 126,252	$ 1,091,773	$ 3,245,554	$ 220,422	$ (769,946)