Dividend and Other Capital-Related Restrictions (Details) $ in Millions	Dec. 31, 2021 USD ($)
Dividend and Other Capital-Related Restrictions [Abstract]
Equity to total capitalization ratio, low end of range (in hundredths)	47.20%
Equity to total capitalization ratio, high end of range (in hundredths)	57.60%
Equity to total capitalization ratio	52.90%
Unrestricted Retained Earnings Per State Regulatory Commissions Dividend Restrictions	$ 1,558
Capitalization, Short term debt, long term debt and equity	14,321
Maximum total capitalization	$ 15,332