Income Taxes (Net Deferred Income Tax Asset) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Loss reserve	$ 183,883	$ 177,237
Net operating loss carryforward	167,089
Foreign tax credits	74,253	55,026
Unearned premium reserve	43,020	46,146
Unfunded pension liability	29,903	14,045
Alternative minimum tax credits	21,438	41,693
Deferred expenses	19,351	17,447
Deferred compensation	15,437	14,189
Uncollectible reinsurance reserve	5,675	5,675
Investment impairments	4,620	4,129
Other assets	17,724	14,254
Total deferred tax assets	582,393	389,841
Net unrealized investment gains	79,450	56,095
Deferred acquisition costs	58,571	64,487
Net unrealized foreign currency gains	46,738	45,251
Net fair value income	29,633	29,002
Gain on tender of debt	27,395	27,395
Bond market discount	2,183	2,609
Other liabilities	5,640	15,901
Total deferred tax liabilities	249,610	240,740
Net deferred tax assets	$ 332,783	$ 149,101