One way to thanks such a person is:

> 1. Thank you for being so scrupulous.
>
> 1. Thank you for your scrupulous reply.  

But I am not sure which one is the better choice.

The following sense is to the point:

> **[scru·pu·lous][1]**  (of a person or process) diligent, thorough, and extremely attentive to details.
> 
> "the research has been carried out with scrupulous attention to
> detail"
> 
> synonyms: careful, meticulous, painstaking, thorough, assiduous,
> sedulous, attentive, conscientious, punctilious, searching, close,
> minute, rigorous, particular, strict
> 
> "scrupulous attention to detail"

What do you think?


  [1]: https://www.google.com/search?rlz=1C1CHZL_enIR762IR762&ei=fBwEXJejJcn3kwWR-474Aw&q=scrupulous&oq=scrupulous&gs_l=psy-ab.3..35i39l2j0i67j0j0i67j0i20i263j0l3j0i67.17569.28044..28582...1.0..1.853.3862.3-1j3j1j2......0....1..gws-wiz.......0i71j0i10.GcnBErz9uqE