Real Estate and Other Investments - Additional Information (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($) investment	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Maximum amount of investment in long-term notes payable \| $	$ 26,635	$ 28,377
Number of real estate investment held for sale \| investment	0
Maximum \| Investments in Joint Ventures \| Total Assets
Debt Instrument [Line Items]
Percent of fair value	2.00%
Maximum \| Investments in Joint Ventures \| Sales Revenue, Services, Net
Debt Instrument [Line Items]
Percent of fair value	20.00%
Maximum \| Investments in Joint Ventures \| Assets Held
Debt Instrument [Line Items]
Percent of fair value	10.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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