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Significant Accounting Policies Update - Additional Information (Detail) | 12 Months Ended |
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Dec. 31, 2018 | Dec. 31, 2017 | Mar. 31, 2018
Summary Of Significant Accounting Policies [Line Items] |  |  |
U.S. corporate tax rate |  | 35.00% |
Scenario Plan [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
U.S. corporate tax rate | 21.00% |  |
Property Leasing Business [Member] | Maximum [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Percentage of revenue remaining performance obligation. |  |  | 2.00%
Wholly Owned Property [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Ownership interest in property |  |  | 100.00%
Commercial Real Estate [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Ownership interest in property |  |  | 0.00%

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