Learn English – A saying that means “our best friends are those we have known for a long time”

The idiom out of the frying pan into the fire may suggest what you are referring to:

• Fig. said when you move from a bad or difficult situation to one that is worse.(Typically: get ~; go ~; jump ~.)

Source: www.dictionary.cambridge.org

[I'm reposting the earlier comment by Janus Bahs Jacquet as an answer, as this seems a better option than having this question linger unanswered yet undeleted (and it doesn't deserve to be closed)...]

The example you quote here works fine for me too, but it’s fundamentally different from the one in Emanuel’s question. It’s basically a cleft version of “He’s been off (for) a long time”. If that is indeed the meaning that Emanuel was trying to get through, then he shouldn’t have been using the present tense of the cleaving verb with the simple past of the underlying matrix verb: “It was a long time that I did this” could work for “I did this (for) a long time”, but not “It’s a long time that I did this”. At least not to me.