Mortgage Loans on Real Estate (Allowance for Loan Losses Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning allowance balance			$ (14,142)
Ending allowance balance	$ (7,527)		(7,527)
Specific Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning allowance balance	(4,552)	$ (9,316)	(7,842)	$ (12,333)
Charge-offs	2,977	0	5,078	143
Recoveries	461	0	5,483	4,375
Change in provision for credit losses	(213)	(1,302)	(4,046)	(2,803)
Ending allowance balance	(1,327)	(10,618)	(1,327)	(10,618)
General Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning allowance balance	(6,300)	(7,500)	(6,300)	(10,300)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Change in provision for credit losses	100	600	100	3,400
Ending allowance balance	$ (6,200)	$ (6,900)	$ (6,200)	$ (6,900)