How to Display Related Model Data on the Edit Page?

I have two models: User and DetailUser. I want to display the name from DetailUser on the edit page. However, I'm unable to display it using

detailUser.name

detailUser.name

. Why is this happening?

Model User.php

public function userDetail()
{
    return $this->hasOne(UserDetail::class, 'user_id', 'id');
}

public function userDetail()
{
    return $this->hasOne(UserDetail::class, 'user_id', 'id');
}

Model UserDetail.php

public function user()
{
    return $this->belongsTo(User::class, 'user_id', 'id');
}

public function user()
{
    return $this->belongsTo(User::class, 'user_id', 'id');
}