Consolidated Statements of Shareholders' Equity (USD $) In Thousands	Total	[CommonStockMember]	[PreferredStockMember]	[AdditionalPaidInCapitalMember]	[AccumulatedOtherComprehensiveIncomeMember]	[AccumulatedOtherComprehensiveIncomeMember] [CurrencyTranslationAdjustmentMember]	[AccumulatedOtherComprehensiveIncomeMember] [UnfundedPensionObligationMember]	[AccumulatedOtherComprehensiveIncomeMember] [UnrealizedGainsLossesOnInvestmentsMember]	[RetainedEarningsMember]	[TreasuryStockMember]
Balance at beginning of year at Dec. 31, 2009		$ 82,586	$ 20,800	$ 3,357,004	$ 84,927	$ 82,843	$ (9,938)	$ 12,022	$ 4,100,782	$ (372)
Net income (loss)	852,552								852,552
Dividends on common shares									(157,631)
Dividends on preferred shares	(34,525)								(34,525)
Issuance of common shares		1,447		62,860
Issuance of preferred shares			0	0
Change in currency translation adjustment	(66,742)					(66,742)
Change in pension obligation	(9,221)						(9,221)
Change in unrealized lossess on investments	(4,908)							(4,908)
Repurchase of common shares										(1,082,640)
Balance at end of year at Dec. 31, 2010	7,206,919	84,033	20,800	3,419,864	4,056	16,101	(19,159)	7,114	4,761,178	(1,083,012)
Net income (loss)	(520,291)								(520,291)
Dividends on common shares									(158,764)
Dividends on preferred shares	(47,020)								(47,020)
Issuance of common shares		734		37,160
Issuance of preferred shares			14,950	346,772
Change in currency translation adjustment	(11,834)					(11,834)
Change in pension obligation	(3,917)						(3,917)
Change in unrealized lossess on investments	(949)							(949)
Repurchase of common shares										(396,218)
Balance at end of year at Dec. 31, 2011	6,467,542	84,767	35,750	3,803,796	(12,644)	4,267	(23,076)	6,165	4,035,103	(1,479,230)
Net income (loss)	1,134,514								1,134,514
Dividends on common shares									(155,993)
Dividends on preferred shares	(61,622)								(61,622)
Issuance of common shares		693		58,048
Issuance of preferred shares			0	0
Change in currency translation adjustment	28,488					28,488
Change in pension obligation	(4,294)						(4,294)
Change in unrealized lossess on investments	(953)							(953)
Repurchase of common shares										(532,927)
Balance at end of year at Dec. 31, 2012	$ 6,933,496	$ 85,460	$ 35,750	$ 3,861,844	$ 10,597	$ 32,755	$ (27,370)	$ 5,212	$ 4,952,002	$ (2,012,157)