Investments (All Other Net Unrealized Investment Gains and Losses in AOCI) (Details) (USD $) In Thousands, unless otherwise specified			9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Other Net Unrealized Investment Gains and Losses [Member] Accumulated Net Unrealized Investment Gain (Loss) Pre Tax [Member]		Sep. 30, 2013 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, 2013 Other Net Unrealized Investment Gains and Losses [Member] Policyholders Account Balances Pre Tax [Member]	Sep. 30, 2013 Other Net Unrealized Investment Gains and Losses [Member] Deferred Income Tax Liability Benefit [Member]	Sep. 30, 2013 Other Net Unrealized Investment Gains and Losses [Member] Accumulated Net Unrealized Investment Gain (Loss) [Member]
Balance	$ 79,544	$ 147,287	$ 376,777	[1]	$ (147,089)	$ (2,164)	$ (80,468)	$ 147,056
Net investment gains (losses) on investments arising during the period			(157,976)	[1]	0	0	55,291	(102,685)
Reclassification adjustment for (gains) losses included in net income			(10,987)	[1]	0	0	3,846	(7,141)
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs			0	[1]	72,334	0	(25,317)	47,017
Impact of net unrealized investment (gains) losses on policyholders' account balance			0	[1]	0	(7,489)	2,621	(4,868)
Balance	$ 79,544	$ 147,287	$ 207,814	[1]	$ (74,755)	$ (9,653)	$ (44,027)	$ 79,379

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