Investments in and Advances to Joint Ventures - Revenues Earned By the Company from Unconsolidated Joint Ventures and Interest Income (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue from contracts:
Other	$ 0.1	$ 0.2	$ 0.3	$ 0.6
Revenue and other income	1.7	3.0	3.5	6.1
Unconsolidated Joint Ventures [Member]
Revenue from contracts:
Total revenue from contracts with customers	1.6	2.8	3.2	5.5
Unconsolidated Joint Ventures [Member] | Asset and Property Management Fees [Member]
Revenue from contracts:
Total revenue from contracts with customers	1.5	2.2	3.0	4.5
Unconsolidated Joint Ventures [Member] | Leasing commissions and development fees [Member]
Revenue from contracts:
Total revenue from contracts with customers	$ 0.1	$ 0.6	$ 0.2	$ 1.0