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
	Mar. 31, 2023	Mar. 31, 2022
Revenue from contracts:
Other	$ 0.2	$ 0.4
Revenue and other income	1.8	3.1
Unconsolidated Joint Ventures [Member]
Revenue from contracts:
Total revenue from contracts with customers	1.6	2.7
Unconsolidated Joint Ventures [Member] | Asset and Property Management Fees [Member]
Revenue from contracts:
Total revenue from contracts with customers	1.5	2.3
Unconsolidated Joint Ventures [Member] | Leasing commissions and development fees [Member]
Revenue from contracts:
Total revenue from contracts with customers	$ 0.1	$ 0.4