Other Delinquency Statistics (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Mar. 31, 2020
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]		$ 4,471
Serious delinquency rate	[2]		0.36%
Period Loan Receivable Becomes Nonaccrual Status		90 days
Conventional Mortgage Loan [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]		$ 2,816
Serious delinquency rate	[2]		0.26%
Past due 90 days or more still accruing interest			$ 0
Loans on nonaccrual status	[3]		11,890
Conventional mortgage loans on non-accrual status with no allowance for credit losses			4,600
Real Estate Loan [Member]
Financing Receivable, Past Due [Line Items]
Past due 90 days or more still accruing interest			5,317
Loans on nonaccrual status	[3]		11,890
US Government Agency Insured Loans [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]		$ 1,655
Serious delinquency rate	[2]		1.85%
Past due 90 days or more still accruing interest			$ 5,317
Loans on nonaccrual status	[3]		$ 0
Mortgage Receivable [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]	$ 5,035
Serious delinquency rate	[2]	0.36%
Past due 90 days or more still accruing interest		$ 5,570
Loans on nonaccrual status	[3]	11,510
Mortgage Receivable [Member] | Conventional Mortgage Loan [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]	$ 2,813
Serious delinquency rate	[2]	0.26%
Past due 90 days or more still accruing interest		$ 0
Loans on nonaccrual status	[3]	11,510
Mortgage Receivable [Member] | US Government Agency Insured Loans [Member]
Financing Receivable, Past Due [Line Items]
In process of foreclosure	[1]	$ 2,222
Serious delinquency rate	[2]	1.86%
Past due 90 days or more still accruing interest		$ 5,570
Loans on nonaccrual status	[3]	$ 0

[1] Includes loans where the decision of foreclosure or similar alternative such as pursuit of deed-in-lieu of foreclosure has been reported.

[2] Loans that are 90 days or more past due or in the process of foreclosure expressed as a percentage of the recorded investment in the total loan portfolio class.

[3] Includes conventional mortgage loans with contractual principal or interest payments 90 days or more past due and not accruing interest as well as loans modified within the previous six months under our temporary loan modification plan. As of March 31, 2020, $4.6 million of these conventional mortgage loans on non-accrual status did not have an associated allowance for credit losses.