Fair Value of Assets and Liabilities (Level 3 by Pricing Source) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Separate account assets	$ 44,601,720		$ 42,942,758
Other assets	1,995
Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other long-term investments	739	[1]
Other assets	0	[1]
External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other long-term investments	315	[1]
Other assets	1,995	[2]
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other long-term investments	132,051		152,345
Reinsurance recoverable	1,732,094		1,747,757
Subtotal excluding separate account assets	6,201,921		7,486,456
Separate account assets	44,601,720	[3]	42,942,758	[3]
Total assets	50,803,641		50,429,214
Future policy benefits	1,793,137		1,783,595
Total liabilities	1,793,137		1,783,595
Other assets	22,627		25,225
Fair Value, Measurements, Recurring [Member] | Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Equity Securities	0	[1]
Reinsurance recoverable	1,732,094	[1]
Total assets	1,825,096	[1]
Future policy benefits	1,793,137	[1]
Total liabilities	1,793,137	[1]
Fair Value, Measurements, Recurring [Member] | External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Equity Securities	207	[2]
Reinsurance recoverable	0	[2]
Total assets	75,107	[2]
Future policy benefits	0	[2]
Total liabilities	0	[2]
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	92,263	[1]
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	3,292	[2]
Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	0	[1]
Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	69,298	[2]
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Equity Securities	207
Other long-term investments	1,054
Reinsurance recoverable	1,732,094
Total assets	1,900,203
Future policy benefits	1,793,137
Total liabilities	1,793,137
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other long-term investments	1,054		1,213
Reinsurance recoverable	1,732,094		1,747,757
Subtotal excluding separate account assets	1,900,203		1,887,394
Separate account assets	0	[3]	0	[3]
Total assets	1,900,203		1,887,394
Future policy benefits	1,793,137		1,783,595
Total liabilities	1,793,137		1,783,595
Other assets	1,995		0
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	95,555
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	$ 69,298

[1] Represents valuations reflecting both internally-derived and market inputs, as well as third-party pricing information or quotes. See below for additional information related to internally-developed valuation for significant items in the above table.

[2] Represents unadjusted prices from independent pricing services and independent indicative broker quotes where pricing inputs are not readily available.

[3] Separate account assets represent segregated funds that are invested for certain customers. Investment risks associated with market value changes are borne by the customers, except to the extent of minimum guarantees made by the Company with respect to certain accounts. Separate account liabilities are not included in the above table as they are reported at contract value and not fair value in the Company’s Statements of Financial Position.