It means that the tide currents have shifted. There are two main tides: high tide and low tide. When the tide is high or rising toward high, currents are driven toward the beach. When it is low or dropping toward low, the currents are driven away from the beach.
Some people also use the term to refer to life situations that change. You could say "the tide turned" when someone was seriously ill and became better, or if things were looking bad for someone and changed to a good outlook.
It means reversing the flow or direction of something.
There is no idiom "the tide turned over." There is a saying that "the tide turned," but it's not an idiom because you can figure out what it means by thinking. Tides "turn" when they shift from high tide to low tide - the currents either go toward the beach or away from it depending on what tide is coming up. People say "the tide turned" or "the tide will turn" to mean that situations in life are changing, just in the same way that the tides change.
When the Tide Turned - 1915 I was released on: USA: 25 June 1915
my wang
When the Tide Turned - 1915 II was released on: USA: 20 March 1915
my wang
The tide turned in favor of the United States during the battle of midway
The word tide mean befall.
Low tide
Stalingrad
Saratoga
Gettysburg
it turned the tide of the pacific theater