Since no one answer your Post I will give a try.
Does your CPU cooler come with one or two fans? If it comes with 2 fans then make sure you have them installed in a Push-Pull configuration. Otherwise if both fans are positioned in a way that both blows inwards or outwards that will decrease the heat efficiency of the unit. Must be in a Push-Pull position to work correctly.
The 5950X has a Maximum Operation Temperature of 90C with a CPU Cooler TDP Rating of 105 Watts. Your CPU Cooler is strong enough to able to keep your CPU below 80c easily.
As to your high idle temps you might have several background apps running which is causing the CPU to run hotter when at idle.
Or you have poor Air Circulation inside your Computer case. To check this remove the side panel and see if the Temps are lower. If they are that mean you have a Air Circulation problem inside your computer case.
When it starts to idle and gets to 70c check to see if the CPU Fans are running at maximum and see what apps are running at the time.
It really shouldn't reach 70c during idle unless the CPU Cooler is not correctly installed or it isn't working correctly or poor air circulation.