I will be flying with Air China into Beijing from Virginia, and have 19 hours layover to Bali

I will be flying into PEK from Maryland, arriving at PEK at 18:35pm, and have layover about 19 hours before go to Bali, Indonesia. Do I need transit visa? Is anyone have experience that. This is first time I use China Airline. I am worry? Please comment if you have experience?