Fair Value Measurements (Narrative) (Details) $ in Thousands			3 Months Ended
	Mar. 31, 2022 USD ($) investment	Dec. 31, 2021 USD ($) investment	Mar. 31, 2022 USD ($) investment
Financial Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis
Real estate fund investments	$ 13,402	$ 7,730	$ 13,402
Real estate fund investments
Financial Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis
Number of investments held by fund (investment) | investment	3	3	3
Real estate fund investments	$ 13,402	$ 7,730	$ 13,402
Real estate fund investments	322,383		322,383
Level 3 | Real estate fund investments
Financial Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis
Real estate fund investments	$ 322,383		$ 322,383