after my engine starts the starter is still turning

i have a 2008 dodge caravan with 3.3 engine and in the morning or if i park it long time like over 8 hours when i crank it engine starts and starter keeps on turning 2 or 3 more seconds it does starts normaly if i dont park it long time This van have wireless ignition so it is a fob key and does not matter if i hold the fob turned too long or too little it has its own crank time THANK YOU !!