Mortgage Loans on Real Estate (Allowance for Loan Losses Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020		Jun. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning allowance balance (1)	$ (19,776)	[1]	$ (9,179)
Charge-offs	1,485		1,485
Recoveries	712		712
Change in provision for credit losses	(2,510)		(4,507)
Ending allowance balance	(20,089)		(20,089)
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning allowance balance (1)	(19,776)	[1]	(9,179)
Charge-offs	1,485		1,485
Recoveries	712		712
Change in provision for credit losses	(860)		(2,857)
Ending allowance balance	(18,439)		(18,439)
Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning allowance balance (1)	0	[1]	0
Charge-offs	0		0
Recoveries	0		0
Change in provision for credit losses	(1,650)		(1,650)
Ending allowance balance	$ (1,650)		$ (1,650)

[1] (1) Upon adoption of authoritative guidance effective January 1, 2020, we updated our accounting policies and methodology for calculating the general loan loss allowance, resulting in an adjustment to our mortgage loan valuation allowance. See Note 1 for further details.