Consolidated Statements Of Changes In Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Balance at Dec. 31, 2012	$ 5,185,366	$ 1,474	$ 3,052,454	$ 4,001,096	$ 830,403	$ (2,700,061)
Stock plan exercises	(13,806)	8	(13,814)
Stock plan compensation expense	50,004		50,004
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(1,111)		(1,111)
Dividends	(74,128)			(74,128)
Acquisition of common stock	(398,180)					(398,180)
Net income	488,907			488,907
Other comprehensive income (loss)	(403,573)				(403,573)
Balance at Dec. 31, 2013	4,833,479	1,482	3,087,533	4,415,875	426,830	(3,098,241)
Stock plan exercises	(20,505)	8	(20,513)
Stock plan compensation expense	49,354		49,354
Change in tax benefit from share-based payment arrangements	14,900		14,900
Dividends	(77,495)			(77,495)
Acquisition of common stock	(218,270)					(218,270)
Net income	470,907			470,907
Other comprehensive income (loss)	128,937				128,937
Balance at Dec. 31, 2014	5,181,307	1,490	3,131,274	4,809,287	555,767	(3,316,511)
Stock plan exercises	(17,564)	7	(17,571)
Stock plan compensation expense	38,773		38,773
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	4,067		4,067
Dividends	(94,168)			(94,168)
Acquisition of common stock	(284,651)			0		(284,651)
Net income	141,555			141,555
Other comprehensive income (loss)	(437,218)				(437,218)
Balance at Dec. 31, 2015	$ 4,523,967	$ 1,497	$ 3,148,409	$ 4,856,674	$ 118,549	$ (3,601,162)