Investments (All Other Net Unrealized Investment Gains and Losses in AOCI) (Details) (USD $) In Thousands, unless otherwise specified			9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Other Net Unrealized Investment Gains and Losses [Member] Accumulated Net Unrealized Investment Gain (Loss) Pre Tax [Member]		Sep. 30, 2012 Other Net Unrealized Investment Gains and Losses [Member] Deferred Costs Policy Acquisition And Sales Inducements And Valuation Of Business Acquired, Pre Tax [Member]	Sep. 30, 2012 Other Net Unrealized Investment Gains and Losses [Member] Policyholders Account Balances Pre Tax [Member]	Sep. 30, 2012 Other Net Unrealized Investment Gains and Losses [Member] Deferred Income Tax Liability Benefit [Member]	Sep. 30, 2012 Other Net Unrealized Investment Gains and Losses [Member] Accumulated Net Unrealized Investment Gain (Loss) [Member]
Balance	$ 166,260	$ 160,712	$ 441,680	[1]	$ (192,122)		$ (88,164)	$ 161,394
Net investment gains (losses) on investments arising during the period			(4,629)	[1]	0	0	1,620	(3,009)
Reclassification adjustment for (gains) losses included in net income			(16,612)	[1]	0	0	5,814	(10,798)
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs			0	[1]	30,618	0	(10,723)	19,895
Impact of net unrealized investment (gains) losses on policyholders' account balance			0	[1]	0	(2,279)	798	(1,481)
Balance	$ 166,260	$ 160,712	$ 420,439	[1]	$ (161,504)	$ (2,279)	$ (90,655)	$ 166,001

[1] Includes cash flow hedges. See Note 5 for additional discussion of our cash flow hedges.