Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

SEGMENT AND GEOGRAPHIC DISCLOSURES - Additional Information (Detail) $ in Thousands			3 Months Ended	12 Months Ended
	Dec. 01, 2018 USD ($)	Dec. 01, 2017 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments \| segment				3
Goodwill impairment loss	$ 0	$ 0	$ 75,200	$ 0	$ 75,241	$ 0
IHT
Segment Reporting Information [Line Items]
Goodwill impairment loss					21,140
MS
Segment Reporting Information [Line Items]
Goodwill impairment loss					$ 54,101