Business Dispositions Level 4 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Jun. 30, 2017
Other assets	$ 1,786	$ 1,807
Disposal Group, Including Discontinued Operation, Assets, Current	870	0
Disposal Group, Including Discontinued Operation, Liabilities, Current	611	0
P&C Runoff Subsidiaries [Member]
Disposal Group, Including Discontinued Operation, Consideration		272
HFPI estimated after tax loss	5
Investments and Cash	657	669
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	213	268
Disposal Group, Including Discontinued Operation, Assets, Current	870	937
Disposal Group, Including Discontinued Operation, Liabilities	600	653
Disposal Group, Including Discontinued Operation, Other Liabilities	11	12
Disposal Group, Including Discontinued Operation, Liabilities, Current	$ 611	665
Accounts Receivable [Member] | P&C Runoff Subsidiaries [Member]
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net		$ 71