Summary of Provisional Amounts for Assets Acquired and Liabilities Assumed (Detail) - GulfMark $ in Thousands	Dec. 31, 2018 USD ($)
Assets:
Current assets	$ 77,942
Property and equipment	360,701
Other assets	779
Liabilities:
Current liabilities	33,881
Long term debt	100,000
Other liabilities	20,049
Net assets acquired	$ 285,492

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Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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