Mortgage Loans on Real Estate (Schedule of Financing Receivables Past Due) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Mortgage loans, past due		$ 0
Commercial Mortgage Loans
Financing Receivable, Past Due [Line Items]
2020	$ 518,719
2019	799,514
2018	574,537
2017	480,158
2016	432,635
Prior	1,021,551
Amortized cost	3,827,114	3,457,972
Commercial Mortgage Loans \| Current
Financing Receivable, Past Due [Line Items]
2020	518,719
2019	799,514
2018	574,537
2017	480,158
2016	432,635
Prior	1,021,551
Mortgage loans, current	3,827,114
Commercial Mortgage Loans \| 30 - 59 Days Past Due
Financing Receivable, Past Due [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Mortgage loans, past due	0
Commercial Mortgage Loans \| 60 - 89 Days Past Due
Financing Receivable, Past Due [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Mortgage loans, past due	0
Commercial Mortgage Loans \| Over 90 Days Past Due
Financing Receivable, Past Due [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Mortgage loans, past due	0
Residential Mortgage Loans
Financing Receivable, Past Due [Line Items]
2020	138,749
2019	12,459
2018	0
2017	0
2016	0
Prior	0
Amortized cost	151,208	$ 0
Residential Mortgage Loans \| Current
Financing Receivable, Past Due [Line Items]
2020	138,749
2019	12,459
2018	0
2017	0
2016	0
Prior	0
Mortgage loans, current	151,208
Residential Mortgage Loans \| 30 - 59 Days Past Due
Financing Receivable, Past Due [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Mortgage loans, past due	0
Residential Mortgage Loans \| 60 - 89 Days Past Due
Financing Receivable, Past Due [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Mortgage loans, past due	0
Residential Mortgage Loans \| Over 90 Days Past Due
Financing Receivable, Past Due [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Mortgage loans, past due	$ 0

Amount, after fee received for commitment to originate or purchase, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

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Amount of financing receivable originated five or more years prior to latest fiscal year.

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Amount of financing receivable originated three years prior to latest fiscal year.

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Amount of financing receivable not past due.

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