Real Estate and Other Investments - Schedule of Long-term Notes Payable of Consolidated VIEs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Notes payable	$ 137,963	$ 137,458
VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable	$ 137,963	137,458
Long Term Notes Payable Due 2022 | VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable maturity year	2022
Notes payable	$ 84,730	87,632
Interest rate on long-term notes	4.00%
LIBOR | Long Term Notes Payable Due 2020 | VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable maturity year	2020
Notes payable	$ 10,834	9,702
Basis spread on variable rate	LIBOR
LIBOR | Long Term Notes Payable Due 2021 | VIE, Primary Beneficiary
Debt Instrument [Line Items]
Notes payable maturity year	2021
Notes payable	$ 42,399	$ 40,124
Basis spread on variable rate	90 day LIBOR + 2.5%
Interest rate percentage	2.50%