EXHIBIT 24


                                   POWER OF ATTORNEY
                                   -----------------

KNOWN ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes
and appoints F. Samuel Ebert III his true and lawful attorney-in-fact and agent,
with full power of substitute for him and in his name, place and stead, in any
and all capacities, in connection with the filing for the undersigned on Form 3,
Form 4, and Form 5 under the Securities Act of 1934, as amended, including,
without limiting the generality of the foregoing, to sign the Form 3, Form 4,
and Form 5 in the name and on behalf of the undersigned or on behalf of the
undersigned as a director or officer of the Corporation, and any amendments to
the Form 3, Form 4, or Form 5 and any instrument, contract, document or other
writing, of or in connection with the Form 3, Form 4, and Form 5 or amendments
thereto, and to file the same, with all exhibits thereto, and other documents
in connection therewith, including this power of attorney, with the Securities
and Exchange Commission and any applicable securities exchange or securities
self-regulatory body, granting unto said attorney-in-fact and agents, each
acting alone, full power and authority to do and perform each and every act and
thing requisite and necessary to be done in and about the premises, as fully to
all intents and purposes as he might or could do in person, hereby ratifying and
confirming all that said attorney-in-fact and agents, each acting alone, or
his substitute or substitutes, may lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has signed these presents this 28th day
of March, 2017.



                                   /s/ Gary Huff
                                   ----------------------
                                   Gary Huff