Stock compensation plans	12 Months Ended
Stock compensation plans	Aug. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock compensation plans	Stock compensation plans The Walgreens Boots Alliance, Inc. Omnibus Incentive Plan (the “Omnibus Plan”) which became effective in fiscal 2013, provides for incentive compensation to the Company’s non-employee directors, officers and employees, and consolidates several previously existing equity compensation plans into a single plan. The Company grants stock options, performance shares and restricted units under the Omnibus Plan. Performance shares issued under the Omnibus Plan offer performance-based incentive awards and equity-based awards to key employees. The fair value of each performance share granted assumes that performance goals will be achieved at 100 percent. If such goals are not met, no compensation expense is recognized and any recognized compensation expense is reversed. Restricted stock units are also equity-based awards with performance requirements that are granted to key employees. The performance shares and restricted stock unit awards are both subject to restrictions as to continuous employment except in the case of death, normal retirement or total and permanent disability. Total stock-based compensation expense for fiscal 2017, 2016 and 2015 was $91 million, $115 million and $109 million, respectively. The recognized tax benefit was $78 million, $21 million and $7 million for fiscal 2017, 2016 and 2015, respectively. Unrecognized compensation cost related to non-vested awards at August 31, 2017 was $137 million. This cost is expected to be recognized over three years.

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.