Are we over tablets?

New report predicts tablet shipments will decline until 2018.

Tablet sales growth has been on the decline for several years now.

And a new report published Thursday by research firm International Data Corporation predicts this trend will continue.

Worldwide tablet shipments are going to decline in 2016 by the second straight year, dropping 9.6 percent over last year, IDC says.

The tablet market has seen its peak, according to IDC, and will face "down years" in 2016 and 2017. The report goes on to predict a slight rebound in 2018 driven by "detachable" tablets.

This type of tablet comes with a keyboard, which can be removed. Right now, detachable tablet sales make up about 16 percent of the tablet market. IDC expects it to reach 31 percent by 2020.

Purchases of slate tablets, such as iPads, are declining because "end-users don't have a good enough reason to replace them," according to Jean Philippe Bouchard, IDC's research director of tablets.

This Business Insider story explains that the problem plaguing tablets is that they don't solve a pressing need that can't also be accomplished with a smartphone or PC.

I can relate to this firsthand. I bought an iPad about five years ago, back when I had a job that required more travel. Now it mostly gathers dust in my nightstand as I rely upon my smartphone and laptop.

Tablet manufacturers are shifting focus to detachable tablets, IDC says, and the line is blurring between them and PCs.  A lot of computer manufacturers see tablets as an extension of their market.

"The detachable tablet segment is also considered by some manufacturers, like Apple, as a way to spur replacement cycles of the existing slate tablet installed base, " Bouchard said.

There are still plenty of people buying slate tablets, IDC says.

IDC expects over 100 million slate tablets to ship annually through 2020. And the good news is the firm predicts they will get cheaper, with an average selling price of $157 by 2020.

Worldwide Tablet Share Forecast by Product Type and OS 2015-2020
ProductOS201520162020
Detachable Tablet
Android16 percent
12 percent
20 percent
iOS14 percent
38 percent
29 percent
Windows70 percent
49 percent
51 percent
Slate Tablet
Android72 percent
75 percent
75 percent
iOS25 percent
22 percent
21 percent
Windows3 percent
3 percent
4 percent
Source: IDC Worldwide Quarterly Tablet Tracker