Consolidated Statements Of Shareholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Balance [Member]
Beginning Balance at Dec. 31, 2009	$ 2,108,118,000	$ 3,368,000	$ 871,100,000	$ 6,324,268,000	$ (417,898,000)	$ (4,672,720,000)
Beginning Balance, shares at Dec. 31, 2009		336,800,970
Other comprehensive income, net of tax
Net income (loss)	146,545,000	0	0	146,545,000	0	0
Amortization of net prior service cost, net of taxes	(925,000)
Amortization of actuarial loss, net of taxes	20,944,000
Change in net unrealized gains (losses):
Other Comprehensive Income (Loss), Net of Tax	48,193,000	0	0	0	48,193,000	0
Adjustment for consolidation of QSPEs under ASC Topics 810 and 860	(37,108,000)	0	0	(40,591,000)	3,483,000	0
Dividends	94,145,000	0	0	94,145,000	0	0
Repurchase of common stock	1,706,000	0	0	0	0	1,706,000
Share-based compensation and 401(k) match made with Treasury shares	26,961,000	0	26,961,000	0	0	0
Issuance of nonvested stock (in shares)	0	823,594	(8,000)	0	0	0
Issuance of nonvested stock		8,000
Exercise of stock options	7,845,000	6,000	7,839,000	0	0	0
Exercise of stock options (in shares)		635,892
Tax benefit of stock options and nonvested stock	2,163,000	0	2,163,000	0	0	0
Ending Balance at Dec. 31, 2010	2,206,866,000	3,382,000	908,055,000	6,336,077,000	(366,222,000)	(4,674,426,000)
Ending Balance, shares at Dec. 31, 2010		338,260,456
Other comprehensive income, net of tax
Net income (loss)	599,114,000	0	0	599,114,000	0	0
Amortization of net prior service cost, net of taxes	564,000
Amortization of actuarial loss, net of taxes	23,584,000
Change in net unrealized gains (losses):
Other Comprehensive Income (Loss), Net of Tax	(110,511,000)	0	0	0	(110,511,000)	0
Dividends	111,011,000	0	0	111,011,000	0	0
Repurchase of common stock	224,551,000	0	0	0	0	224,551,000
Share-based compensation and 401(k) match made with Treasury shares	49,996,000	0	49,993,000	0	0	3,000
Issuance of nonvested stock (in shares)	0	473,240	(5,000)	0	0	0
Issuance of nonvested stock		5,000
Exercise of stock options	7,840,000	4,000	7,836,000	0	0	0
Exercise of stock options (in shares)		373,534
Tax benefit of stock options and nonvested stock	2,513,000	0	2,513,000	0	0	0
Ending Balance at Dec. 31, 2011	2,420,256,000	3,391,000	968,392,000	6,824,180,000	(476,733,000)	(4,898,974,000)
Ending Balance, shares at Dec. 31, 2011		339,107,230
Other comprehensive income, net of tax
Net income (loss)	623,925,000	0	0	623,925,000	0	0
Amortization of net prior service cost, net of taxes	563,000
Amortization of actuarial loss, net of taxes	32,295,000
Change in net unrealized gains (losses):
Other Comprehensive Income (Loss), Net of Tax	(130,945,000)	0	0	0	(130,945,000)	0
Dividends	141,681,000	0	0	141,681,000	0	0
Repurchase of common stock	311,632,000	0	0	0	0	311,632,000
Share-based compensation and 401(k) match made with Treasury shares	42,058,000	0	42,056,000	0	0	2,000
Issuance of nonvested stock (in shares)	0	535,807	(6,000)	0	0	0
Issuance of nonvested stock		6,000
Exercise of stock options	45,973,000	16,000	45,957,000	0	0	0
Exercise of stock options (in shares)	(1,666,000)	1,622,801
Tax benefit of stock options and nonvested stock	9,670,000	0	9,670,000	0	0	0
Ending Balance at Dec. 31, 2012	$ 2,557,624,000	$ 3,413,000	$ 1,066,069,000	$ 7,306,424,000	$ (607,678,000)	$ (5,210,604,000)
Ending Balance, shares at Dec. 31, 2012		341,265,838