Segment Information - Total Assets (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Summary of assets by segment
Total assets	$ 143,268	$ 147,480
Advice and Wealth Management [Member]
Summary of assets by segment
Total assets	13,592	13,270
Asset Management [Member]
Summary of assets by segment
Total assets	8,671	8,401
Annuities [Member]
Summary of assets by segment
Total assets	94,997	98,276
Protection [Member]
Summary of assets by segment
Total assets	17,738	18,039
Corporate and Other [Member]
Summary of assets by segment
Total assets	$ 8,270	$ 9,494