| Component: (Network and Table) | |
|---|---|
| Network | 173 - Disclosure - Postretirement and Other Employee Benefits - Summary of Estimated Future Benefit Payments (Detail) (http://www.bottomline.com/taxonomy/role/DisclosurePostretirementAndOtherEmployeeBenefitsSummaryOfEstimatedFutureBenefitPayments) |
| Table | (Implied) |
| Reporting Entity [Axis] | 0001073349 (http://www.sec.gov/CIK) |
| Postemployment Benefits [Abstract] | Period [Axis] |
|---|---|
2016-06-30 | |
Postemployment Benefits [Abstract] | |
2017 | |
2018 | |
2019 | |
2020 | |
2021 | |
2022-26 |