Operating Segments (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($) segment	Dec. 31, 2014 USD ($)
Segment Reporting [Abstract]
Number of reportable segments \| segment	2	2
Revenue from foreign sources \| $	$ 22,422	$ 18,772	$ 16,306

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration