General:
* Detailed
* Complex
* Intricate
* Thorough
* Exhaustive
* Comprehensive
* Ornate
* Grandiose
* Exquisite
* Sophisticated
* Refined
Formal:
* Circumspect
* Meticulous
* Minute
* Precise
Informal:
* Fancy
* Over-the-top
* Extravagant
* Gushing
The best synonym for "elaborate" will depend on the specific situation and the intended meaning.