Significant Accounting Policies - Investment in Marketable Securities (Narrative) (Details)	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($) marketableSecurity security
Real Estate [Line Items]
Proceeds from sale of marketable securities		$ 7,800,000	$ 0
Number of marketable securities sold | security		1
Proceeds from the repayment of debt marketable securities		$ 3,700,000	$ 4,500,000
Number of securities repaid | security		1	1
Equity marketable securities	$ 0	$ 0
Number of securities sold | marketableSecurity			1
Proceeds from sale of equity marketable securities	4,200,000		$ 0
Marketable securities, realized loss		6,500,000
Marketable securities, unrealized gain			$ 600,000
Commercial mortgage-backed securities
Real Estate [Line Items]
Cost basis of commercial mortgage backed securities	11,500,000	11,500,000
Unrealized loss	1,900,000	300,000
Fair value of security in a continuous unrealized loss position for less than 12 months	$ 9,600,000	$ 11,200,000