Good afternoon and welcome to the PRA Group Earnings Conference Call. At this time, all participants are in the listen-only mode, later we will conduct the question-and-answer session and instructions will follow at that time. (Operator Instructions) As a reminder this conference call is being recorded.
I would now like to turn the conference over to Ms. Darby Schoenfeld, Vice President of Investor Relations for PRA Group. Please go ahead.
Thank you. Good afternoon, everyone, and thank you for joining us. With me today are Kevin Stevenson, President and Chief Executive Officer; and Pete Graham, Executive Vice President and Chief Financial Officer.
We will make forward-looking statements during the call, which are based on management's current expectations. We caution listeners that these forward-looking statements are subject to risks, uncertainties and assumptions and could cause actual results to differ materially from our expectations. Please refer to the earnings press release and our SEC filings for a detailed discussion of these factors.
The earnings release, the slide presentation that we will be using during today's webcast and call and our SEC filings can be found on the Investor Relations section of our website at www.pragroup.com. Additionally, a replay of this call will be available shortly after its conclusion, and the information needed to listen is in the earnings press release. All comparisons mentioned today will be between Q1 of 2018 and Q1 of 2017, unless otherwise noted.
I'd now like to turn the call over to Kevin Stevenson, our President and Chief Executive Officer.
Kevin P. Stevenson
Well, thank you, Darby, and good afternoon, everyone. Thank you for joining us on our first quarter 2018 conference call. Almost two years ago, we recognized that we let attrition drive our collector workforce to a level that was not matched to the portfolios we owned. Additionally, we started to see signs of increasing supply in US core, which compounded the issue. To improve performance, we began increasing our collector workforce in June of 2016. And by the end of the first quarter of this year, we reached what we believe is an appropriate capacity at almost 3,100 US-based collectors.
As a reminder, when we pool our number of collectors or employees, we use a full-time equivalent convention. In addition to this aggressive hiring campaign, we've also opened two new call centers, we significantly enhanced our digital outreach and platform and launched an updated letter strategy and process. Globally, PRA now has over 5,600 employees. I've been so impressed by the teamwork, enthusiasm and dedication that we've shown over the last two years to accommodate the growth and the regulatory changes the Company has experienced during this time. As a result, 2018 is off to a great start, and we achieved another record quarter, and this time in global cash collections, which increased 12%. This was primarily driven by a 22% increase in US call center cash collections and a second quarter in a row of record Europe Core cash collections.
Portfolio investment was $168 million during the quarter,