Discontinued Operations- Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Disposal Group, Including Discontinued Operation, Assets		$ 13,089
National Holdings Corporation [Member]
Disposal Group, Including Discontinued Operation, Assets	$ 13,100
Share Price	$ 3.25

Amount classified as assets attributable to disposal group held for sale or disposed of.

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