Certain Transfers of Financial Assets (Details 3) - Mortgage Servicing Rights	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
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)	9.08%	9.06%
Expected prepayment speeds (percent)	14.51%	13.11%
Weighted-average life, in years	5 years 4 months 24 days	5 years 9 months 18 days