Apex domains cannot have CNAME records.
Question and response
Question
dig dallas-idc.com. NS
Answer
dallas-idc.com. 5 NS ns1.dallas-idc.com.
dallas-idc.com. 5 NS ns3.dallas-idc.com.
dallas-idc.com. 5 NS ns2.dallas-idc.com.
Authority
The response has no authority records.
Additional
ns1.dallas-idc.com. 5 A 64.31.5.3
ns2.dallas-idc.com. 5 A 64.31.5.4
ns1.dallas-idc.com. 5 AAAA 2607:ff68:5:0:0:0:0:300
ns2.dallas-idc.com. 5 AAAA 2607:ff68:5:0:0:0:0:400
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0