Investments in Joint Ventures - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
MG [Member]
Schedule of Investments [Line Items]
Percentage of ownership	33.00%
Recorded cost	$ 835,000
Dividends declared	$ 0	$ 0
Gongchang [Member]
Schedule of Investments [Line Items]
Percentage of ownership	24.03%
Recorded cost	$ 1,340,000
Dividends declared	$ 1,364,000	$ 377,000
ATR [Member] \| Akers AB [Member]
Schedule of Investments [Line Items]
Ownership interest percentage	59.88%
ATR [Member] \| TISCO [Member]
Schedule of Investments [Line Items]
Ownership interest by minority holder	40.12%

Percentage of ownership interest in joint venture which is accounted for under the cost method.

No definition available.

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- Definition

The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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- Definition

Dividends received on equity and other investments during the current period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 16
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3337-108585

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Details

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- Details

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