Default Battery Eaten Up In Idle State By Android OS..

Since last couple of days I am facing a strange issue ...
Usually while I sleep I am used to checking how much battery is still there ...e.g if the battery is say 95% full at night the next day it becomes at the most 93% (phone in the idle state) !!!

Now comes my problem , since a couple of days i have noticed that the battery is going down by about 7 to 8% in idle state , then i checked the battery consumption in the phone settings & to my surprise I saw "Android OS" taking 56% of battery in idle state & that means something is continuosly running in the background eating up my precious battery...What the hell can it be ??

I have not installed any indifferent app recently ...
SAMSUNG GALAXY NOTE 3 SM-N900
THIS DEVICE IS KICKASS !!!

SOMETIMES IT KICKS MY OWN ASS !!!