Certain Transfers of Financial Assets (Details 3) - Mortgage Servicing Rights	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Average discount rates (percent)	9.06%	9.55%
Expected prepayment speeds (percent)	13.11%	9.77%
Weighted-average life, in years	5 years 9 months 18 days	7 years