We see this same pattern often: We have finished a sentence; then we throw in something that renames the subject of that sentence.
…We decided to spend the weekend away — my husband and I….The company had been in the red — Mitchell Engineering.
…That is what I wanted to tell you — that he was here today.
The grammar here is that the element after the complete sentence is an appositive to the subject of the sentence. In each case, it can be inserted into the sentence for the subject.
…My husband and I decided to spend the weekend away.
…Mitchell Engineering had been in the red.
…That he was here today is what I wanted to tell you.
Since the appositive comes after the sentence has concluded, it takes a dash.
If the sentence is asking a question, there are two interrogs.
…Who decided to go forward? Your boss?
…Was the bank in error? Chase Bank?
…Was that your understanding? That he would meet you there?