Real Estate and Other Investments - Schedule of Long-term Notes Payable of Consolidated VIEs (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Notes payable	$ 159,577	$ 137,963
VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable	159,577	137,963
Long Term Notes Payable Due 2022 | VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable	$ 83,234	84,730
Interest rate on long-term notes	4.00%
LIBOR | Long Term Notes Payable Due 2020 | VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable	$ 10,842	10,834
Basis spread on variable rate	LIBOR
LIBOR | Long Term Notes Payable Due 2021 | VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable	$ 65,501	$ 42,399
Basis spread on variable rate	90 day LIBOR + 2.5%
Interest rate percentage	2.50%