Ride-hailing services are emerging as a mode of transportation, necessitating modeling and control methods for efficient management. In this paper, we propose a hierarchical control framework for the optimal positioning of idle vehicles for maximizing service level. An economic model predictive controller at the upper layer repositions idle vehicles between urban regions towards balancing interregional responsiveness, while a coverage controller at the lower layer distributes idle vehicles over space towards balancing intraregional responsiveness. Studies on detailed simulations of an urban road network suggest the potential of the method for improving performance.