Fair Values of Assets and Liabilities Fair Value of Assets & Liabilities (Non-Recurring) (Details) - VIEs, not primary beneficiary [Member] - RiverSource Tax Advantaged Investments Inc [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets and liabilities measured at fair value
Affordable housing partnership, amount	$ 255	$ 270
Nonrecurring basis [Member] | Level 3 [Member]
Assets and liabilities measured at fair value
Affordable housing partnership, amount	$ 130	$ 158