Fair Value of Assets and Liabilities (Changes in Level 3 Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Included In Earnings
Transfers out of Level 3			$ 0	[1]
Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period			0
Included In Earnings
Realized investment gains (losses), net			0
Asset management fees and other income			0
Included in other comprehensive income (loss)			0
Net investment income			1
Purchases			0
Sales			(747)
Issuances			0
Settlements			0
Other			(230)	[2]
Transfers into Level 3			976
Transfers out of Level 3			0	[1]
Fair Value, end of period			0
Included In Earnings
Realized investment gains (losses), net			0
Asset management fees and other income			0
Interest credited to policyholders' account balances			0
Debt Securities [Member] | Foreign Government Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period					1,219
Included In Earnings
Realized investment gains (losses), net					0
Asset management fees and other income					0
Included in other comprehensive income (loss)					(12)
Net investment income					(1)
Purchases, Sales, Issuances and Settlements
Transfers into Level 3					0	[1]
Transfers out of Level 3					(1,206)	[1]
Fair Value, end of period					0
Included In Earnings
Realized investment gains (losses), net					0	[3]
Asset management fees and other income					0	[3]
Interest credited to policyholders' account balances					0	[3]
Debt Securities [Member] | Corporate Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period	89,658		74,255		63,634
Included In Earnings
Realized investment gains (losses), net	1,606		46		1,083
Asset management fees and other income	0		0		0
Included in other comprehensive income (loss)	2,271		5,472		3,072
Net investment income	4,634		4,579		4,195
Purchases, Sales, Issuances and Settlements					(10,830)
Purchases	5,400		8,702
Sales	(29)		0
Issuances	0		0
Settlements	(8,286)		(5,356)
Other			0	[2]
Transfers into Level 3	11,992	[1]	51,135		13,101	[1]
Transfers out of Level 3	(11,691)	[3]	(49,175)	[1]	0	[1]
Fair Value, end of period	95,555		89,658		74,255
Included In Earnings
Realized investment gains (losses), net	0	[3]	0		0	[3]
Asset management fees and other income	0	[3]	0		0	[3]
Interest credited to policyholders' account balances	0	[3]	0		0	[3]
Debt Securities [Member] | Asset-backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period	48,563		53,857		43,794
Included In Earnings
Realized investment gains (losses), net	0		0		(1,247)
Asset management fees and other income	0		0		0
Included in other comprehensive income (loss)	1,109		206		(963)
Net investment income	649		430		17
Purchases, Sales, Issuances and Settlements					29,676
Purchases	30,311		0
Sales	0		0
Issuances	0		0
Settlements	(11,334)		(5,930)
Other			0	[2]
Transfers into Level 3	0	[1]	0		0	[1]
Transfers out of Level 3	0	[1]	0	[1]	(17,420)	[1]
Fair Value, end of period	69,298		48,563		53,857
Included In Earnings
Realized investment gains (losses), net	0	[3]	0		(654)	[3]
Asset management fees and other income	0	[3]	0		0	[3]
Interest credited to policyholders' account balances	0	[3]	0		0	[3]
Other Long-term Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period	1,213		0
Included In Earnings
Realized investment gains (losses), net	(2,326)		(1,285)
Asset management fees and other income	(3)		(19)
Included in other comprehensive income (loss)	0		0
Net investment income	0		0
Purchases	2,166		262
Sales	0		0
Issuances	0		0
Settlements	4		0
Other			0	[2]
Transfers into Level 3	0	[1]	2,255
Transfers out of Level 3	0	[1]	0	[1]
Fair Value, end of period	1,054		1,213
Included In Earnings
Realized investment gains (losses), net	(1,349)	[3]	(1,311)
Asset management fees and other income	(3)	[3]	(19)
Interest credited to policyholders' account balances	0	[3]	0
Trading Asset [Member] | Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period	203		0
Included In Earnings
Realized investment gains (losses), net	0		0
Asset management fees and other income			(27)
Asset management fees and other income	4
Included in other comprehensive income (loss)	0		0
Net investment income	0		0
Purchases	0		0
Sales	0		0
Issuances	0		0
Settlements	0		0
Other			230	[2]
Transfers into Level 3	0	[1]	0	[1]
Transfers out of Level 3	0	[1]	0	[1]
Fair Value, end of period	207		203
Included In Earnings
Realized investment gains (losses), net	0	[3]	0	[3]
Asset management fees and other income	4	[3]	(27)	[3]
Interest credited to policyholders' account balances	0	[3]	0	[3]
Other Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period	0
Included In Earnings
Realized investment gains (losses), net	0
Asset management fees and other income	0
Included in other comprehensive income (loss)	(5)
Net investment income	0
Purchases	2,000
Sales	0		223,036
Issuances	0
Settlements	0
Transfers into Level 3	0	[1]
Transfers out of Level 3	0	[1]
Fair Value, end of period	1,995		0
Included In Earnings
Realized investment gains (losses), net	0	[3]
Asset management fees and other income	0	[3]
Interest credited to policyholders' account balances	0	[3]
Future Policy Benefits [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period	(1,783,595)		(164,283)		(10,874)
Included In Earnings
Realized investment gains (losses), net	230,349		(1,396,276)		45,258
Asset management fees and other income	0
Included in other comprehensive income (loss)	0
Net investment income	0
Purchases, Sales, Issuances and Settlements					(198,667)
Purchases	0		0
Sales	0
Issuances	(239,891)		0
Settlements	0
Transfers into Level 3	0	[1]	0	[1]
Transfers out of Level 3	0	[1]
Fair Value, end of period	(1,793,137)		(1,783,595)		(164,283)
Included In Earnings
Realized investment gains (losses), net	179,477	[3]	(1,403,609)		42,759	[3]
Asset management fees and other income	0	[3]	0		0	[3]
Interest credited to policyholders' account balances	0	[3]	0		0	[3]
Other Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period					(53)
Included In Earnings
Realized investment gains (losses), net					53
Fair Value, end of period					0
Reinsurance Recoverable [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, beginning of period	1,747,757		186,735		40,351
Included In Earnings
Realized investment gains (losses), net	(244,519)		1,348,271		(43,339)
Asset management fees and other income	0		0		0
Included in other comprehensive income (loss)	0		0		0
Net investment income	0		0		0
Purchases, Sales, Issuances and Settlements					189,723
Purchases	228,856		212,751
Sales	0		0
Issuances	0		0
Settlements	0		0
Other			0	[2]
Transfers into Level 3	0	[1]	0		0	[1]
Transfers out of Level 3	0	[1]	0	[1]	0	[1]
Fair Value, end of period	1,732,094		1,747,757		186,735
Included In Earnings
Realized investment gains (losses), net	(194,274)	[3]	1,356,358		(40,069)	[3]
Asset management fees and other income	0	[3]	0		0	[3]
Interest credited to policyholders' account balances	$ 0	[3]	$ 0		$ 0	[3]

[1]   (1) Transfers into or out of Level 3 are generally reported as the value as of the beginning of the quarter in which the transfer occurs.

[2]   (3) Other primarily represents reclasses of certain assets between reporting categories.

[3]   (2) Unrealized gains or losses related to assets still held at the end of the period do not include amortization or accretion of premiums and discounts.