Related Party Transactions (Affiliated Commercial Mortgage Loan) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019
Related Party Transaction [Line Items]
Commercial mortgage and other loans	$ 1,765,770	[1]	$ 1,471,522
Affiliated Entity | Commercial Mortgage Loans
Related Party Transaction [Line Items]
Interest Rates	4.65%
Commercial mortgage and other loans	$ 74,005

[1] December 31, 2020 amounts include the impacts of the January 1, 2020 adoption of ASU 2016-13. See Note 2 for details.