Derivatives Instruments Level 4 Derivative Collateral Arrangements (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 403	$ 488
Derivative Asset, Collateral, Obligation to Return Cash, Offset	378	369
Securities Received as Collateral	57
Fair Value of Securities Received as Collateral that Can be Resold or Repledged	$ 207	$ 100
Information about Sources and Uses of Collateral that is Received Through Resale Agreements and Securities Borrowing Agreements	As of September 30, 2016, and December 31, 2015, the Company had no repledged securities and did not sell any securities. In addition, as of September 30, 2016, and December 31, 2015, non-cash collateral accepted was held in separate custodial accounts and was not included in the Company’s Condensed Consolidated Balance Sheets.	As of September 30, 2016, and December 31, 2015, the Company had no repledged securities and did not sell any securities. In addition, as of September 30, 2016, and December 31, 2015, non-cash collateral accepted was held in separate custodial accounts and was not included in the Company’s Condensed Consolidated Balance Sheets.
Collateral Pledged [Member]
Derivative [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 1,200	$ 1,100
Liability [Member]
Derivative [Line Items]
Securities Received as Collateral	$ 219	$ 100