The research firm found that Q4 tablet shipments dropped more than 13 percent to 65.9 million units.
Total shipments for the year were were 206.8 million, down 10 percent from the the prior year and below IDC's original shipment trajectory of 211.3 million units.
The research firm's reports have been decidedly grim about the outlook for traditional tablets, but momentum in the category has not stalled completely.
IDC said that shipments 2-in-1 devices, or tablets with detachable keyboards, reached an all-time high of 8.1 million devices. The detachable trend has been growing for some time, with Apple, Google and Microsoft already rolling out detachable tablets to compete with PC makers such as Dell and HP.
"This quarter was unique as we had new detachables in the market from all three of the major platform players," said Jitesh Ubrani, IDC senior research analyst for mobile devices.
Ubrani noted that the iPad Pro was the top selling detachable during the quarter, allowing Apple to maintain its hold on the tablet market despite its 25 percent year-over-year decline.
Amazon's spot on the quarterly leaderboard is due to the surprise success of its $50 Kindle tablet. For all of 2015, Apple, Samsung, Lenovo, ASUS and Huawei make up the top five vendors.
In terms of pricing, IDC says the race to the bottom is not yet over for traditional slate tablets. For detachables, however, the price trend is a bit different.
IDC posits that Apple sold more than two million iPad Pros, which run around $950 a pop. Microsoft sold around 1.6 million Surface devices, a majority of which were from the Pro line and not the more affordable Surface 3.
"With these results, it's clear that price is not the most important feature considered when acquiring a detachable -- performance is," said Jean Philippe Bouchard, research director for tablets at IDC.