This is the 12072nd most frequent Russian word.
идеей
The Russian word "идеей" means "idea" in the instrumental case.
The word 'идея' is in the nominative case singular, part of the phrase 'хорошая идея', used to denote possession of an idea that is positive.
У меня есть хорошая идея.
I have a good idea.
Here 'идеей' is in the instrumental case singular, used within the phrase 'своей идеей' indicating the tool or means by which the action 'sharing' is performed.
Он предложил поделиться своей идеей.
He suggested sharing his idea.
In this sentence, 'идеей' is in the instrumental case singular, demonstrating the influence or source of inspiration motivating the subject 'мы'.