Related Party Transactions - Summary of Components of Due to Affiliates (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Total components due to affiliates	$ 896,640	$ 887,660
Accrued Stockholder Servicing Fee [Member]
Related Party Transaction [Line Items]
Total components due to affiliates	683,505	605,411
Performance Participation Allocation [Member]
Related Party Transaction [Line Items]
Total components due to affiliates	143,215	192,648
Accrued Management Fee [Member]
Related Party Transaction [Line Items]
Total components due to affiliates	25,666	22,253
Accrued Affiliate Service Provider Expenses [Member]
Related Party Transaction [Line Items]
Total components due to affiliates	14,929	10,151
Advanced Organization and Offering Costs [Member]
Related Party Transaction [Line Items]
Total components due to affiliates	3,579	4,090
Other [Member]
Related Party Transaction [Line Items]
Total components due to affiliates	$ 25,746	$ 53,107