| Component: (Network and Table) | |
|---|---|
| Network | 1070 - Disclosure - Summary of Cost and Accumulated Depreciation of Premises and Equipment (Detail) (http://www.belmontsavings.com/taxonomy/role/DisclosureSummaryOfCostAndAccumulatedDepreciationOfPremisesAndEquipment) |
| Table | Property, Plant and Equipment [Table] |
| Reporting Entity [Axis] | 0001522420 (http://www.sec.gov/CIK) |
| Legal Entity [Axis] | Entity [Domain] |
| Property, Plant and Equipment [Line Items] | Period [Axis] | |
|---|---|---|
2016-12-31 | 2015-12-31 | |
Land | ||
Buildings | ||
Leasehold improvements | ||
Furniture and equipment | ||
Property, Plant and Equipment, Gross, Total | ||
Accumulated depreciation | ( | ( |
Premises and equipment, net | 2,355,000 | 2,657,000 |