voucher vs commercial document

voucher and commercial document both are nouns.

Word	Noun	Adjective	Verb	Adverb
voucher	Yes	No	No	No
commercial document	Yes	No	No	No

As nouns, commercial document is a hypernym of voucher; that is, commercial document is a word with a broader meaning than voucher:

voucher: a negotiable certificate that can be detached and redeemed as needed
commercial document: a document of or relating to commerce

Other hypernyms of voucher include commercial instrument.

voucher (noun)	commercial document (noun)
a negotiable certificate that can be detached and redeemed as needed	a document of or relating to commerce
a document that serves as evidence of some expenditure
someone who vouches for another or for the correctness of a statement