I my employer responsible for showing income from my LTD on my 2017 W2 when I received a W2 from the insurance company?
If it is in Box 14, then I would not worry, it is listed correct. You should enter it in TurboTax exactly as it appears on your W-2. You would need to enter both W-2s.
That LTD is probably money that was deducted from your pay to pay for long-term disability insurance. If that's what it is, it's just for your information. It does not affect your tax return, but enter it in TurboTax anyway.