Fair Value of Assets and Liabilities (Level 3 by Pricing Source) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Separate account assets	$ 44,179,734		$ 44,601,720
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other long-term investments	30,278		132,051
Reinsurance recoverable	654,058		1,732,094
Subtotal excluding separate account assets	4,668,811		6,201,921
Separate account assets	44,179,734	[1]	44,601,720	[1]
Total assets	48,848,545		50,803,641
Future policy benefits	669,989		1,793,137
Total liabilities	669,989		1,793,137
Other assets	24,956		22,627
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Equity Securities	279		207
Other long-term investments	407		1,054
Reinsurance recoverable	654,058		1,732,094
Total assets	842,272		1,900,203
Future policy benefits	669,989		1,793,137
Total liabilities	669,989		1,793,137
Other assets	5,250		1,995
Fair Value, Inputs, Level 3 [Member] | Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Equity Securities	0	[2]	0	[2]
Other long-term investments	19	[2]	739	[2]
Reinsurance recoverable	654,058	[2]	1,732,094	[2]
Total assets	743,641	[2]	1,825,096	[2]
Future policy benefits	669,989	[2]	1,793,137	[2]
Total liabilities	669,989	[2]	1,793,137	[2]
Other assets	0	[2]	0	[2]
Fair Value, Inputs, Level 3 [Member] | External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Equity Securities	279	[3]	207	[3]
Other long-term investments	388	[3]	315	[3]
Reinsurance recoverable	0	[3]	0	[3]
Total assets	98,631	[3]	75,107	[3]
Future policy benefits	0	[3]	0	[3]
Total liabilities	0	[3]	0	[3]
Other assets	5,250	[3]	1,995	[3]
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	407		1,054
Reinsurance recoverable	654,058		1,732,094
Subtotal excluding separate account assets	842,272		1,900,203
Separate account assets	0	[1]	0	[1]
Total assets	842,272		1,900,203
Future policy benefits	669,989		1,793,137
Total liabilities	669,989		1,793,137
Other assets	5,250		1,995
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	96,192		95,555
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member] | Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	89,564	[2]	92,263	[2]
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member] | External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	6,628	[3]	3,292	[3]
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	86,086		69,298
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member] | Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	0	[2]	0	[2]
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member] | External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	86,086	[3]	69,298	[3]
Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	0
Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities [Member] | Internal Pricing [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	0	[2]
Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities [Member] | External Priced [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable Securities, Fixed Maturities	$ 0	[3]

[1] 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 Unaudited Interim Statements of Financial Position.

[2] Represents valuations which could incorporate internally-derived and market inputs. See below for additional information related to internally-developed valuation for significant items in the above table.

[3] Represents unadjusted prices from independent pricing services and independent non-binding broker quotes where pricing inputs are not readily available.