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	Mar. 31, 2019	Dec. 31, 2018
Separate Accounts Disclosure [Abstract]
Variable annuity	$ 71,748	$ 66,913
VUL insurance	7,034	6,451
Other insurance	30	29
Threadneedle investment liabilities	4,759	4,532
Total	$ 83,571	$ 77,925