Segment Information - Total Assets (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Summary of assets by segment
Total assets	$ 145,191	$ 147,480
Advice and Wealth Management [Member]
Summary of assets by segment
Total assets	13,826	13,270
Asset Management [Member]
Summary of assets by segment
Total assets	8,264	8,401
Annuities [Member]
Summary of assets by segment
Total assets	96,260	98,276
Protection [Member]
Summary of assets by segment
Total assets	17,985	18,039
Corporate and Other [Member]
Summary of assets by segment
Total assets	$ 8,856	$ 9,494