Although I've been an ongoing viewer of PBS ever since it first came in to being decades ago, I've never heard of a series titled "PBS Idea Channel". However, I just now found the following reference to it on Wikipedia, that states PBS Idea Channel is a PBS web series on YouTube:

PBS Digital Studios is a YouTube channel and network through which PBS distributes original educational web video content. It comprises both original series and partnerships with existing YouTube channels. Most of the series are about science, pop culture, art, food, news, and music....// The PBS Digital Studios network has...over 7 million subscribers. Popular series found on their channels include Crash Course, Blank on Blank, It’s Okay To Be Smart, and the multiple Webby Award-winning PBS Idea Channel....

Here's the YouTube link to the series.

I never, till now, realized there's such a thing as the PBS Digital Studios channel on YouTube.