Impairment Charges and Reserves - Summary of Significant Unobservable Inputs (Detail) - Fair Value Measurements [Member] $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred equity interests, Fair Value	$ 90.4
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred equity interests, Fair Value	90.4
Preferred Equity Interests [Member] | Level 3 [Member] | Discounted Cash Flow [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred equity interests, Fair Value	$ 90.4
Preferred Equity Interests [Member] | Level 3 [Member] | Discounted Cash Flow [Member] | NOI Growth Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs rate	1.00%
Preferred Equity Interests [Member] | Level 3 [Member] | Discounted Cash Flow [Member] | Minimum [Member] | Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs rate	8.90%
Preferred Equity Interests [Member] | Level 3 [Member] | Discounted Cash Flow [Member] | Minimum [Member] | Terminal Capitalization Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs rate	8.20%
Preferred Equity Interests [Member] | Level 3 [Member] | Discounted Cash Flow [Member] | Maximum [Member] | Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs rate	10.10%
Preferred Equity Interests [Member] | Level 3 [Member] | Discounted Cash Flow [Member] | Maximum [Member] | Terminal Capitalization Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs rate	9.60%