Fair Value of Assets and Liabilities (Level 3 by Pricing Source) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivables from parent and affiliates	$ 76,956	$ 212,696
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	10,290,463	225
Other long-term investments	0	115,266
Reinsurance recoverables	345,918	3,012,653
Receivables from parent and affiliates	50,023	37,340
Total assets	58,743,297	45,103,812
Future policy benefits	12,326,533	3,134,077
Total liabilities	13,257,141	3,134,077
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	5,076
Short-term investments	450	450
Cash equivalents	375	225
Other long-term investments	0	1,565
Reinsurance recoverables	345,918	3,012,653
Receivables from parent and affiliates	2,776	7,664
Total assets	598,221	3,196,358
Future policy benefits	12,326,533	3,134,077
Total liabilities	12,326,533	3,134,077
Fair Value, Measurements, Recurring | Level 3 | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	156,255	127,308
Fair Value, Measurements, Recurring | Level 3 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	87,371	46,493
Fair Value, Measurements, Recurring | Level 3 | Internal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	1,700
Short-term investments	450	450
Cash equivalents	375	225
Other long-term investments		1,565
Reinsurance recoverables	345,918	3,012,653
Receivables from parent and affiliates	0	0
Total assets	489,698	3,126,188
Future policy benefits	12,326,533	3,134,077
Total liabilities	12,326,533	3,134,077
Fair Value, Measurements, Recurring | Level 3 | Internal | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	141,255	111,295
Fair Value, Measurements, Recurring | Level 3 | Internal | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	0	0
Fair Value, Measurements, Recurring | Level 3 | External
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	3,376
Short-term investments	0	0
Cash equivalents	0	0
Other long-term investments		0
Reinsurance recoverables	0	0
Receivables from parent and affiliates	2,776	7,664
Total assets	108,523	70,170
Future policy benefits	0	0
Total liabilities	0	0
Fair Value, Measurements, Recurring | Level 3 | External | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	15,000	16,013
Fair Value, Measurements, Recurring | Level 3 | External | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities	$ 87,371	$ 46,493