The two were spotted running errands together in Los Angeles earlier, stopping by a few stores to shop without their daughter, Coco.
"When you love someone, you want them to be happy, even if it's not with you," she told the publication.
"In divorce you always have regret. We were married for a long time, so it's not like we didn't try."
Cox, who is now dating Snow Patrol band member Johnny McDaid, added, "You can love somebody so much, but it's not the life you should be living together. I think David and I are supposed to be the way we are now."
This past April, Arquette became a father again after his girlfriend Christina McLarty gave birth to a son named Charlie West.
"Mom, dad and baby are doing well," Arquette's rep told People at the time. "They appreciate all of your well wishes and thank you for respecting their privacy at this time."
Arquette and McClarty began dating in 2011. In mid-2012, however, they broke up. "Sadly I'm single again," Arquette tweeted at the time. "A long distance relationship proved to be too difficult." They later got back together and the rest is history!