The $86 is likely the accumulated estimated earnings over several months. Until your earning reach $100, Google doesn't issue a check. Your finalized earnings simply accrue until they reach $100.
You can verify this by clicking on the three dots (
⋮) next to the word "Balance" and selecting "View Payments". From there you can click "View Transactions and Documents". That will give you a list of items that have changed your balance.
You will likely see several months of earnings that come from the estimates. There may be separate line items for "AdSense for Search" and "AdSense for Content". You will notice that these earnings may not match the estimates for that month. They will likely be lower. When Google "finalizes" earning from the estimates it takes out invalid clicks and click for which the advertiser did not pay Google. You also may notice further negative items for adjustments for "Invalid Traffic" that get taken out after earnings are finalized.