General:
* Complete
* Full
* Thorough
* Exhaustive
* Inclusive
* All-encompassing
* Wide-ranging
* Global
Formal:
* Encompassing
* Embracing
* All-inclusive
* Universal
Informal:
* All-around
* In-depth
* Everything
* The whole shebang
Specific to particular contexts:
* In education: Curricular, broad-based
* In research: In-depth, detailed
* In healthcare: Holistic, multidisciplinary
The best synonym will depend on the specific context and the desired tone.