Financing Activity - Carrying and Fair Values of Mortgage Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Mortgage loans, carrying value	$ 669,781	$ 749,396
Carrying Value | Mortgage Loan
Debt Instrument [Line Items]
Mortgage loans, carrying value	670,300	751,500
Fair Value | Mortgage Loan
Debt Instrument [Line Items]
Mortgage loans, fair value	$ 650,300	$ 733,700