Investments (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	$ 337,603	$ 344,442	$ 688,095	$ 722,792
Investment Income Investment Expense	9,269	7,006	18,821	14,316
Investment income, net of related expenses	328,334	337,436	669,274	708,476
Availableforsale Securities Member
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	193,388	191,030	384,806	375,591
Mortgage Loans On Real Estate Member
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	16,000	13,593	30,966	27,328
Policy Loans Member
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	16,334	16,724	33,117	33,095
Funds Withheld At Interest [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	62,992	111,700	178,006	264,760
Short Term Investments Member
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	781	883	1,769	1,808
Investment Receivable [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	36,752	0	36,752	0
Other Aggregated Investments Member
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment Revenue	$ 11,356	$ 10,512	$ 22,679	$ 20,210