UPDATE statement help

Hi,
I've got this stored proc that needs to update multiple rows in a table (DETAIL) using specific criteria that's in a subquery, but I get this error, I believe on the WHERE clause at the end of the update:
PLS-00201: identifier 'smy.CYCLE_ID' must be declared

CREATE PROCEDURE SP_DETAIL
   ( PARM_MARKET IN VARCHAR2 )
IS
    dtLastRpt DATE;      
    dtPrevRpt DATE;
    iMarketID NUMBER;
BEGIN

SELECT market_id INTO iMarketID
FROM MARKET
WHERE MARKET = PARM_MARKET;

SELECT MAX(wmd.START_TIME)
INTO dtLastRpt
FROM MARKET_DAILY md
WHERE md.market_id = iMarketID
    AND md.job_id = 41
    AND md.start_time < SYSDATE;

SELECT MAX(md.START_TIME)
INTO dtPrevRpt
FROM MARKET_DAILY md
WHERE md.market_id = iMarketID
    AND md.job_id = 41
    AND md.start_time < dtLastBLNHB;

UPDATE DETAIL det
SET (rejects, modified_by, modify_date) =
(SELECT
   smy.REJECT, 'myid' as modified_by, sysdate as modify_date
FROM
   ACTUALS act
 , CYCLE cyc
 , SUMMARY smy
WHERE
     act.CYCLE_ID = cyc.CYCLE_ID
 AND smy.CYCLE_ID = cyc.CYCLE_ID
 AND smy.MONTH_YEAR = act.MONTH_YEAR
 AND cyc.MARKET_ID = iMarketID
 AND act.EVENT_ID = 32
 AND act.CYCLE_TYPE = 'M'
 AND act.actual_time < dtLastRpt
 AND act.actual_time > dtPrevRpt
)
WHERE det.CYCLE_ID = smy.cycle_id
    and det.MONTH_YEAR = smy.month_year;

END;

Anybody have any ideas?