Acquisitions (First Quarter 2018) - Additional Information (Detail) - Laurus Transaction Advisors, LLC. [Member]	12 Months Ended
Dec. 31, 2018
Business Acquisition, Contingent Consideration [Line Items]
Effective date of acquisition	Feb. 01, 2018
Acquired entity, name	Laurus Transaction Advisors, LLC.

Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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