There is no job security, and lay-offs are not tied to your performance, but rather to office politics. Every fall, they restructure and let good people go, while, often, useless employees manage to stay on. It's a weird practice. It is also hard to advance internally: Citizens will always pick external candidates over their own, and the pay ranges candidates are offered for the same job as you are frankly outrageous. So: great if you are external, just don't stay too long or get too comfy, and don't expect to move up through hard work and dedication, as that will never happen.
Culture on paper sounds good, "Customers - Colleagues - Community - Shareholders" - though it's all about the Shareholders now, to nobody's surprise.