What does "of necessity" mean? Is it an idiom?

[Guest]

Dear teacher,
Why do people use "of necessity" and place it between "will " and "be". Can it replaced with another word?
"There will of necessity be a ceiling to the amount of money put at the new manager's disposal."
And please explain the sentence.
Thanks very much.

[Alan]

[Guest]

Dear teacher,
I quickly understand what you have explained. Your explanation is great.
Many thanks to you.

[Guest]

.
The idiomatic of necessity is an adverb, and as such is relatively mobile, so it can rest comfortably in either of the following positions:

There will of necessity be a ceiling to the amount of money put at the new manager's disposal.

Of necessity, there will be a ceiling to the amount of money put at the new manager's disposal.

After the auxiliary of a verb phrase is a common position for most adverbs:

There will of necessity be...
I have never been married.
You can certainly enjoy pizza here.
He is lovingly dismantling the old Gatling gun.
.