Segment Reporting - Summary of Total Assets by Segment (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total assets	$ 36,628,499	$ 33,039,823
Multifamily [Member]
Segment Reporting Information [Line Items]
Total assets	11,537,484	9,695,916
Industrial [Member]
Segment Reporting Information [Line Items]
Total assets	11,188,957	10,564,172
Net Lease [Member]
Segment Reporting Information [Line Items]
Total assets	5,059,427	4,271,196
Hotel [Member]
Segment Reporting Information [Line Items]
Total assets	2,357,585	2,427,554
Retail [Member]
Segment Reporting Information [Line Items]
Total assets	714,678	419,198
Other Properties [Member]
Segment Reporting Information [Line Items]
Total assets	155,485	145,411
Office [Member]
Segment Reporting Information [Line Items]
Total assets	133,277	138,912
Real Estate Debt [Member]
Segment Reporting Information [Line Items]
Total assets	5,254,130	4,565,385
Other (Corporate) [Member]
Segment Reporting Information [Line Items]
Total assets	$ 227,476	$ 812,079