Organization, Basis of Presentation and Summary of Significant Accounting Policies - Aggregate Fair Value and Carrying Value of Short and Long-term Debt (Detail) $ in Thousands	Dec. 31, 2017 USD ($)
Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Short-term debt - related party	$ 1,000
Long-term debt - related party	1,200
Long-term debt	1,558
Total long-term debt	3,758
Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Short-term debt - related party	1,000
Long-term debt - related party	1,200
Long-term debt	1,558
Total long-term debt	$ 3,758