Policyholder Account Balances, Future Policy Benefits and Claims and Separate Account Liabilities Policyholder Account Balances, Future Policy Benefits and Claims and Separate Account Liabilities (Separate Account Liabilities) (Details 2) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Separate Accounts Disclosure [Abstract]
Variable annuity	$ 73,467	$ 69,606
VUL insurance	7,154	6,659
Other insurance	33	33
Threadneedle investment liabilities	4,633	3,912
Total	$ 85,287	$ 80,210