Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions  | 
 Jan. 02, 2018  
USD ($) 
 | 
|---|---|
| Accounting Policies [Line Items] | |
| National investment banking expenses | $ 0.1 | 
| X | ||||||||||
- Definition Accounting Policies [Line Items] No definition available. 
  | 
| X | ||||||||||
- Definition It represents the national investment banking expenses. No definition available. 
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