Contingencies, Commitments and Guarantees (details) - Gain Contingencies - United States Fidelity & Guaranty Company v. American Re-Insurance Company, et al. [Member] $ in Millions	70 Months Ended
	Jun. 30, 2016 USD ($) item	Aug. 17, 2010 item
Gain Contingencies
Number of other reinsurers beside American Re against which judgment was entered in a reinsurance dispute | item		3
Number of reinsurers against which judgment was entered in a reinsurance dispute who are subsidiaries of the same company | item		2
Number of discrete issues for which the Court of Appeals remanded the case for trial | item	2
Total settlement amount | $	$ 519
Settlement amount, reinsurance recoverables | $	238
Interest related to settlement award | $	$ 281
Annual interest rate accruing on judgment not yet paid	9.00%