Select limit from DBA_PROFILES where profile='DEFAULT' and resource_name='IDLE_TIME';
select profile||': '||limit
    FROM   dba_profiles,
           (SELECT limit AS def_idl_tm
            FROM   dba_profiles
            WHERE  profile = 'DEFAULT'
            AND    resource_name = 'IDLE_TIME')
    WHERE  resource_name='IDLE_TIME'
    AND    ((replace(limit,'DEFAULT',def_idl_tm) IN ('UNLIMITED', NULL))
      OR    (lpad(replace(limit,'DEFAULT',def_idl_tm),40,'0') >
             lpad('15',40,'0')));