Fair Value Measurements (Financial Assets and Liabilities Not Measured at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Carrying Amount
Assets
Cash equivalents	$ 427,601	$ 393,070
Liabilities:
Mortgages payable (excluding deferred debt issuance costs, net)	1,096,544	1,164,544
Level 1 | Fair Value
Assets
Cash equivalents	427,601	393,070
Level 2 | Fair Value
Liabilities:
Mortgages payable (excluding deferred debt issuance costs, net)	$ 1,064,122	$ 1,130,000