Laravel 5.2 manyToMany与3个枢轴列的关系问题

I have a problem with connecting database models in Laravel.

Tables: users, companies, company_details  

Now, I want to connect them, like, each user can have multiple companies, and every company has its company_details.

users: user_id, user_username...  

companies: company_id, company_....  

company_details: company_detail_id, ..., company_detail_company_id

[Pivot table] = company_user: id, user_id, company_id

My User.php Model looks like this:

public function companies()
{
    return $this->belongsToMany('App\Models\Company');
}

How can I get the values from company_details table?

Does your Company Model have a details() method?