Capital stock	12 Months Ended
Aug. 31, 2017
Capital Stock [Abstract]
Capital stock	Capital stock In connection with the Company’s capital policy, the Board of Directors has authorized share repurchase programs. In April 2017, Walgreens Boots Alliance authorized a stock repurchase program, which authorized the repurchase of up to $1.0 billion of Walgreens Boots Alliance common stock prior to the program’s expiration on December 31, 2017. In May 2017, the Company completed this $1.0 billion stock repurchase program. In June 2017, Walgreens Boots Alliance authorized a new stock repurchase program, which authorizes the repurchase of up to $5.0 billion of Walgreens Boots Alliance common stock prior to the program’s expiration on August 31, 2018. The Company purchased 59.0 million and 1.3 million shares under stock repurchase programs in fiscal 2017 and 2016 at a cost of $4.8 billion and $110 million, respectively. The Company determines the timing and amount of repurchases based on its assessment of various factors including prevailing market conditions, alternate uses of capital, liquidity, the economic environment and other factors. The timing and amount of these purchases may change at any time and from time to time. The Company has repurchased, and may from time to time in the future repurchase, shares on the open market through Rule 10b5-1 plans, which enable a company to repurchase shares at times when it otherwise might be precluded from doing so under insider trading laws. In addition, the Company continued to repurchase shares to support the needs of the employee stock plans. Shares totaling $457 million were purchased to support the needs of the employee stock plans during fiscal 2017 as compared to $1.0 billion and $500 million in fiscal 2016 and fiscal 2015, respectively. At August 31, 2017, 39 million shares of common stock were reserved for future issuances under the Company’s various employee benefit plans.

Capital stock

In connection with the Company’s capital policy, the Board of Directors has authorized share repurchase programs. In April 2017, Walgreens Boots Alliance authorized a stock repurchase program, which authorized the repurchase of up to $1.0 billion of Walgreens Boots Alliance common stock prior to the program’s expiration on December 31, 2017. In May 2017, the Company completed this $1.0 billion stock repurchase program. In June 2017, Walgreens Boots Alliance authorized a new stock repurchase program, which authorizes the repurchase of up to $5.0 billion of Walgreens Boots Alliance common stock prior to the program’s expiration on August 31, 2018. The Company purchased 59.0 million and 1.3 million shares under stock repurchase programs in fiscal 2017 and 2016 at a cost of $4.8 billion and $110 million, respectively.

The Company determines the timing and amount of repurchases based on its assessment of various factors including prevailing market conditions, alternate uses of capital, liquidity, the economic environment and other factors. The timing and amount of these purchases may change at any time and from time to time. The Company has repurchased, and may from time to time in the future repurchase, shares on the open market through Rule 10b5-1 plans, which enable a company to repurchase shares at times when it otherwise might be precluded from doing so under insider trading laws.

In addition, the Company continued to repurchase shares to support the needs of the employee stock plans. Shares totaling $457 million were purchased to support the needs of the employee stock plans during fiscal 2017 as compared to $1.0 billion and $500 million in fiscal 2016 and fiscal 2015, respectively. At August 31, 2017, 39 million shares of common stock were reserved for future issuances under the Company’s various employee benefit plans.