Compine multiple variables into a single CSV

I am pulling two queries from Active Directory and assigning them to different variables. I'd like to combine these variables into a single $Output and export it to a CSV file. I'm running into 2 issues:

1. Some of the users don't have an assigned manager so I'm getting errors back when the script runs. I'm also not sure if the 2 variables will line up properly, as there will now be blank values in the $Managers output.
2. I can't seem to get the data to output to a CSV file successfully. At the moment I'm getting the CSV file but each column has "System.Object[]" as the output.
   

This is what I've written up thus far:

# Retrieve a list of active user accounts with a defined list of attributes and assign them to a variable
$Users = (Get-ADUser -Filter {Enabled -eq "True"} -Properties DisplayName, GivenName, Surname, Title, TelephoneNumber, StreetAddress, City, State, PostalCode, Country, Mail, UserPrincipalName, Department, Manager |  Select DisplayName, GivenName, Surname, Title, TelephoneNumber, StreetAddress, City, State, PostalCode, Country, Mail, UserPrincipalName, Department, Manager)

# Create an array to store the output
$Output = @()

# Based on the initial query, retrieve manager specific attributes and assign them to a veritable
$Managers = ForEach ($Manager in $Users) {Get-ADUser -Identity $Manager.manager -Properties DisplayName, UserPrincipalName, Mail | select DisplayName, UserPrincipalName, Mail}


# Create a new object to store this information for CSV export
$OutputItem = New-Object Object;

	$OutputItem | Add-Member NoteProperty "Display Name" $Users.DisplayName;
	$OutputItem | Add-Member NoteProperty "First Name" $Users.GivenName;
	$OutputItem | Add-Member NoteProperty "Last Name" $Users.Surname;
	$OutputItem | Add-Member NoteProperty "Title" $Users.Title;
	$OutputItem | Add-Member NoteProperty "Telephone Number" $Users.TelephoneNumber;
	$OutputItem | Add-Member NoteProperty "Street Address" $Users.StreetAddress;
	$OutputItem | Add-Member NoteProperty "City" $Users.City;
	$OutputItem | Add-Member NoteProperty "State" $Users.State;
	$OutputItem | Add-Member NoteProperty "Zip Code" $Users.PostalCode;
	$OutputItem | Add-Member NoteProperty "COuntry" $Users.Country;
	$OutputItem | Add-Member NoteProperty "Email Address" $Users.Mail;
	$OutputItem | Add-Member NoteProperty "UPN" $Users.UserPrincipalName;
	$OutputItem | Add-Member NoteProperty "Department" $Users.Department;
	$OutputItem | Add-Member NoteProperty "Manager" $Managers.DisplayName;
	$OutputItem | Add-Member NoteProperty "Manager UPN" $Managers.UserPrincipalName;
	$OutputItem | Add-Member NoteProperty "Manager Email Address" $Managers.Mail;

# Add the object to our array of output objects
$Output += $OutputItem;

# Export the results to CSV
$Output | Export-CSV "Output.csv" -NoTypeInformation

Appreciate any help =)