Segment Information - Total Assets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Summary of assets by segment
Total assets	$ 144,762	$ 147,480
Advice and Wealth Management [Member]
Summary of assets by segment
Total assets	13,319	13,270
Asset Management [Member]
Summary of assets by segment
Total assets	8,849	8,401
Annuities [Member]
Summary of assets by segment
Total assets	95,802	98,276
Protection [Member]
Summary of assets by segment
Total assets	17,728	18,039
Corporate and Other [Member]
Summary of assets by segment
Total assets	$ 9,064	$ 9,494