Income Taxes - Summary of Deferred Tax Assets and Liabilities (Parenthetical) (Detail) - TRS [Member] $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Income Tax Expense Benefit [Line Items]
Net operating loss carryforwards	$ 18.5
Book or tax differences in joint venture investments	7.0
Capital loss carryforward	$ 4.0
Expiry of net operating loss carryforwards	2024 and 2035

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 25
-Paragraph 20
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=115928272&loc=d3e28680-109314

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant