Insurance (Separate Accounts - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Separate Accounts [Line Items]
Separate account assets	$ 188,445	$ 175,556
Gain (Loss) Recognized on Assets Transferred to Separate Account	$ 0	$ 0	$ 0
Participating Insurance, Percentage of Gross Insurance in Force	3.00%	3.00%
Funding Agreements and Participating Close Out Contracts Included in Separate Accounts with a Guaranteed Minimum Return or Account Value
Schedule Separate Accounts [Line Items]
Average interest rate credited on separate accounts with a guaranteed minimum return or account value	2.92%	2.60%
Pass Through Separate Accounts
Schedule Separate Accounts [Line Items]
Separate account assets	$ 142,500	$ 129,200
Separate Accounts With Minimum Return Or Account Value
Schedule Separate Accounts [Line Items]
Separate account assets	$ 45,900	$ 46,400