Unaudited Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands		Total	Non-Cumulative Preferred Shares	Common Shares	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Unrealized gains on available-for-sale securities	Foreign currency translation adjustments	Common Shares Held in Treasury, at Cost
Balance at beginning of year at Dec. 31, 2012			$ 325,000	$ 561	$ 227,778	$ 5,354,361	$ 287,017	$ 289,956	$ (2,939)	$ (1,025,839)
Common shares issued, net				0
Exercise of stock options					3,093
Amortization of share-based compensation					11,543
Other					78
Net income		256,476				256,476
Net (income) loss attributable to noncontrolling interests	[1]	0				0
Preferred share dividends		(5,484)				(5,484)
Unrealized holding gains (losses) arising during period, net of reclassification adjustment								(29,230)
Portion of other-than-temporary impairment losses recognized in other comprehensive income, net of deferred income tax		(2)						(2)
Foreign currency translation adjustments		(28,222)							(28,222)
Shares repurchased for treasury										(41,600)
Noncontrolling interest	[1]	0
Total shareholders' equity at Mar. 31, 2013		5,335,530
Balance at end of period at Mar. 31, 2013		5,335,530	325,000	561	242,492	5,605,353	229,563	260,724	(31,161)	(1,067,439)
Balance at beginning of year at Dec. 31, 2013		5,647,496	325,000	565	299,517	6,042,154	74,964	80,692	(5,728)	(1,094,704)
Common shares issued, net				2
Exercise of stock options					8,054
Amortization of share-based compensation					14,175
Other					(1,243)
Net income		179,145				179,145
Net (income) loss attributable to noncontrolling interests	[1]	3,355				3,355
Preferred share dividends		(5,484)				(5,484)
Unrealized holding gains (losses) arising during period, net of reclassification adjustment								50,104
Portion of other-than-temporary impairment losses recognized in other comprehensive income, net of deferred income tax		0						0
Foreign currency translation adjustments		(1,349)							(1,349)
Shares repurchased for treasury										(2,122)
Noncontrolling interest	[1]	793,496
Total shareholders' equity at Mar. 31, 2014		6,685,629
Balance at end of period at Mar. 31, 2014		$ 5,892,133	$ 325,000	$ 567	$ 320,503	$ 6,219,170	$ 123,719	$ 130,796	$ (7,077)	$ (1,096,826)

[1] See Note 4.