Investments in and Advances to Joint Ventures - Revenues Earned By the Company from Unconsolidated Joint Ventures and Interest Income (Detail) - Unconsolidated Joint Ventures [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue from contracts:
Total revenue from contracts with customers	$ 2.7	$ 3.0
Other	0.4	0.4
Revenue and other income	3.1	3.4
Asset and Property Management Fees [Member]
Revenue from contracts:
Total revenue from contracts with customers	2.3	2.6
Development Fees, Leasing Commissions and Other [Member]
Revenue from contracts:
Total revenue from contracts with customers	$ 0.4	$ 0.4