Notes Payable (Schedule of Long-term Debt) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022	Mar. 08, 2017
Debt Instrument [Line Items]
Interest rate			4.40%
Total principal amount	$ 450,000	$ 400,000
Less unamortized discount and debt issuance costs	1,471	1,670
Notes payable	448,529	398,330
Unsecured debt
Debt Instrument [Line Items]
Notes payable	$ 373,529	373,330
Unsecured debt | Notes payable | Level 2 | Unsecured Notes One
Debt Instrument [Line Items]
Interest rate	4.40%
Unsecured debt	$ 375,000	375,000	$ 375,000
Unsecured debt | Notes payable | Level 2 | Unsecured Notes Two
Debt Instrument [Line Items]
Unsecured debt	$ 75,000	$ 25,000
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Minimum | Unsecured debt | Notes payable | Level 2 | Unsecured Notes Two
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Maximum | Unsecured debt | Notes payable | Level 2 | Unsecured Notes Two
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%