Slow Cooker Chicken Alfredo

3 boneless, skinless chicken breast halves (about 5 oz each)
1 cup Italian salad dressing
1 (10 3/4 oz) can cream of chicken soup
1 (8 oz) package cream cheese, softened
1 cup chicken broth
1/2 tsp dried thyme
1/2 tsp dried basil
1/2 tsp salt
1/4 tsp black pepper
12 oz fettuccine, cooked, drained

Place chicken and salad dressing in a resealable plastic bag. Chill chicken for 8 to 10 hours.
Transfer chicken and marinade to a slow cooker. Cook, covered, on MEDIUM until an instant read thermometer inserted in center of the meat registers about 180, about 4 hours.
Remove chicken from slow cooker. Shred chicken.
Add soup, cream cheese, broth, thyme, basil, salt, and black pepper to liquid in slow cooker and mix well.
Add chicken to the slow cooker. Cook, covered, on HIGH until heated through, about 10 minutes. Serve over the pasta.