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Stock Compensation Plans - Summary of Plan Activity (Detail) - $ / shares | Jul. 01, 2019 | Jan. 01, 2019 | Jul. 01, 2018 | Jan. 01, 2018 | Jul. 01, 2017 | Jan. 01, 2017
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Issue Date One [Member] |  |  |  |  |  |
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] |  |  |  |  |  |
Shares Issued, Price |  |  |  |  |  | $ 13.76
Shares Issued, Shares |  |  |  |  |  | 18,512
Issue Date Two [Member] |  |  |  |  |  |
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] |  |  |  |  |  |
Shares Issued, Price |  |  |  |  | $ 13.52 |
Shares Issued, Shares |  |  |  |  | 25,155 |
Issue Date Three [Member] |  |  |  |  |  |
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] |  |  |  |  |  |
Shares Issued, Price |  |  |  | $ 13.34 |  |
Shares Issued, Shares |  |  |  | 20,662 |  |
Issue Date Four [Member] |  |  |  |  |  |
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] |  |  |  |  |  |
Shares Issued, Price |  |  | $ 11.57 |  |  |
Shares Issued, Shares |  |  | 27,802 |  |  |
Issue Date Five [Member] |  |  |  |  |  |
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] |  |  |  |  |  |
Shares Issued, Price |  | $ 11.60 |  |  |  |
Shares Issued, Shares |  | 24,834 |  |  |  |
Issue Date Six [Member] |  |  |  |  |  |
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] |  |  |  |  |  |
Shares Issued, Price | $ 12.24 |  |  |  |  |
Shares Issued, Shares | 22,926 |  |  |  |  |

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