Inclusion Criteria:

          -  Men and women, aged 18 years or older on the day of signing the Informed Consent Form
             (ICF).

          -  Histologically confirmed indolent/aggressive DLBCL, FL, MZL, or MCL.

          -  Participants with DLBCL, MZL or MCL must have received at least 1 prior line of
             systemic therapy with documented progression or documented failure to achieve CR or PR
             after the most recent systemic treatment regimen.

          -  Participants with FL must have received at least 2 prior lines of systemic therapy
             with documented progression or documented failure to achieve CR or PR after the most
             recent systemic treatment regimen.

          -  Ineligible for stem cell transplant.

          -  Participants with DLBCL must have failed or refused stem cell transplantation or
             failed first-line salvage therapy if ineligible for transplantation.

          -  Must be willing to undergo an incisional or excisional lymph node or tissue biopsy or
             to provide a lymph node or tissue biopsy from the most recent available archival
             tissue.

          -  Life expectancy of > 3 months.

          -  Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 2 (see
             Appendix D).

          -  Willingness to avoid pregnancy or fathering a child.

          -  Ability to comprehend and willingness to sign an ICF

        Exclusion Criteria:

          -  Evidence of transformed non-Hodgkin lymphoma histologies (with the exception of FL).

          -  Histologically confirmed rare non-Hodgkin B-cell subtypes.

          -  History of or central nervous system lymphoma (either primary or metastatic) or
             leptomeningeal disease.

          -  Prior treatment with idelalisib, other selective PI3Kδ inhibitors, or a pan-PI3K
             inhibitor.

          -  For participants to be treated with bendamustine (Treatment B), prior treatment with
             bendamustine (within 12 months of the start of study treatment). Participants with
             prior bendamustine treatment (> 12 months before the start of study treatment) are
             eligible if they meet the following criteria:

               -  Did not discontinue because of tolerability concerns.

               -  Achieved either partial response (PR) or complete response (CR) to the
                  bendamustine regimen of at least 12 months in duration before
                  relapse/progression.

               -  Experienced progression following a regimen containing an alkylating agent.

          -  For participants to be treated with ibrutinib (Treatment C), prior treatment with a
             Bruton's tyrosine kinase (BTK) inhibitor.

          -  Allogeneic stem cell transplant within the last 6 months or autologous stem cell
             transplant within the last 3 months before the date of the first dose of study
             treatment.

          -  Active graft-versus-host disease following allogeneic transplant.

          -  Hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.