Fair Value Measurements Level 4 Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		$ 227,616	$ 228,348
Assets, Fair Value Disclosure		180,046	181,633
Liabilities		209,057	210,706
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		4,289	3,810
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		99,380	95,907
Reported Value Measurement [Member] | Embedded Derivative Financial Instruments [Member] | Other Liabilities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	[1]	32	38
Reported Value Measurement [Member] | Other Policyholder Funds and Benefits Payable [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	[2]	6,492	6,706
Reported Value Measurement [Member] | Senior Notes [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	[3]	4,241	4,259
Reported Value Measurement [Member] | Junior Subordinated Debt [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	[3]	1,083	1,100
Reported Value Measurement [Member] | Investment Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities		668	619
Reported Value Measurement [Member] | Policy Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		1,436	1,447
Reported Value Measurement [Member] | Mortgages [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		5,659	5,624
Estimate of Fair Value Measurement [Member] | Embedded Derivative Financial Instruments [Member] | Other Liabilities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure		32	38	[1]
Estimate of Fair Value Measurement [Member] | Other Policyholder Funds and Benefits Payable [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure	[2]	6,787	6,898
Estimate of Fair Value Measurement [Member] | Senior Notes [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure	[3]	4,942	4,811
Estimate of Fair Value Measurement [Member] | Junior Subordinated Debt [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure	[3]	1,292	1,304
Estimate of Fair Value Measurement [Member] | Investment Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure		730	682
Estimate of Fair Value Measurement [Member] | Policy Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		1,436	1,447
Estimate of Fair Value Measurement [Member] | Mortgages [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 6,000	$ 5,736

[1] [3]Included in other liabilities in the Condensed Consolidated Balance Sheets.

[2] Excludes guarantees on variable annuities, group accident and health and universal life insurance contracts, including corporate owned life insurance.

[3] Included in long-term debt in the Condensed Consolidated Balance Sheets, except for current maturities, which are included in short-term debt.