Summary of Amounts for Assets Acquired and Liabilities as of Merger Date (Detail) - GulfMark $ in Thousands	Dec. 31, 2019 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