Borrowings, Long-Term Debt (Details) - USD ($) $ in Millions		3 Months Ended
		Nov. 30, 2016	Aug. 31, 2016
Long-Term Debt [Abstract]
Other	[1],[2]	$ 30	$ 32
Total long term debt	[1]	17,777	18,705
Unsecured Pound Sterling Variable Rate Term Loan Due 2019 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1]	$ 1,735	1,833
Maturity year	[1]	2019
1.750% unsecured notes due 2018 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 1,247	1,246
Stated interest rate	[1],[3],[4]	1.75%
Maturity year	[1],[3],[4]	2018
2.600% unsecured notes due 2021 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 1,493	1,493
Stated interest rate	[1],[3],[4]	2.60%
Maturity year	[1],[3],[4]	2021
3.100% unsecured notes due 2023 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 745	744
Stated interest rate	[1],[3],[4]	3.10%
Maturity year	[1],[3],[4]	2023
3.450% unsecured notes due 2026 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 1,886	1,885
Stated interest rate	[1],[3],[4]	3.45%
Maturity year	[1],[3],[4]	2026
4.650% unsecured notes due 2046 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 590	590
Stated interest rate	[1],[3],[4]	4.65%
Maturity year	[1],[3],[4]	2046
1.750% Unsecured Notes Due 2017 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 0	746
Stated interest rate	[1],[3],[4]	1.75%
Maturity year	[1],[3],[4]	2017
2.700% Unsecured Notes Due 2019 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 1,245	1,244
Stated interest rate	[1],[3],[4]	2.70%
Maturity year	[1],[3],[4]	2019
3.300% Unsecured Notes Due 2021 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 1,242	1,242
Stated interest rate	[1],[3],[4]	3.30%
Maturity year	[1],[3],[4]	2021
3.800% Unsecured Notes Due 2024 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 1,987	1,987
Stated interest rate	[1],[3],[4]	3.80%
Maturity year	[1],[3],[4]	2024
4.500% Unsecured Notes Due 2034 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 494	494
Stated interest rate	[1],[3],[4]	4.50%
Maturity year	[1],[3],[4]	2034
4.800% Unsecured Notes Due 2044 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 1,492	1,492
Stated interest rate	[1],[3],[4]	4.80%
Maturity year	[1],[3],[4]	2044
2.875% Unsecured Pound Sterling Notes Due 2020 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 495	521
Stated interest rate	[1],[3],[4]	2.875%
Maturity year	[1],[3],[4]	2020
3.600% Unsecured Pound Sterling Notes Due 2025 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 371	391
Stated interest rate	[1],[3],[4]	3.60%
Maturity year	[1],[3],[4]	2025
2.125% Unsecured Euro Notes Due 2026 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[3],[4]	$ 790	830
Stated interest rate	[1],[3],[4]	2.125%
Maturity year	[1],[3],[4]	2026
3.100% Unsecured Notes Due 2022 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[4],[5]	$ 1,194	1,194
Stated interest rate	[1],[4],[5]	3.10%
Maturity year	[1],[4],[5]	2022
4.400% Unsecured Notes Due 2042 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[4],[5]	$ 492	492
Stated interest rate	[1],[4],[5]	4.40%
Maturity year	[1],[4],[5]	2042
5.250% Unsecured Notes Due 2019 [Member]
Long-Term Debt [Abstract]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	[1],[4],[5],[6]	$ 249	$ 249
Stated interest rate	[1],[4],[5],[6]	5.25%
Maturity year	[1],[4],[5],[6]	2019

[1] All notes are presented net of unamortized discount and debt issuance costs, where applicable, and foreign currency denominated borrowings have been translated using the spot rates at November 30, 2016 and August 31, 2016, respectively.

[2] Other long-term debt represents a mix of fixed and variable rate borrowings in various foreign currencies with various maturities.

[3] Notes are unsubordinated debt obligations of Walgreens Boots Alliance and rank equally in right of payment with all other unsecured and unsubordinated indebtedness of Walgreens Boots Alliance from time to time outstanding.

[4] The fair value & carrying value of the $6 billion, $8 billion, £0.7 billion, €0.75 billion, $4 billion and $1 billion note issuances as of November 30, 2016 was $5.9 billion & $6.0 billion, $7.3 billion & $7.2 billion, $0.9 billion & $0.9 billion, $0.8 billion & $0.8 billion, $1.7 billion & $1.7 billion and $0.3 billion & $0.2 billion, respectively. The fair values of the notes outstanding are Level 1 fair value measures and determined based on quoted market price and translated at the November 30, 2016 spot rate, as applicable.

[5] Notes are senior debt obligations of Walgreens and rank equally with all other unsecured and unsubordinated indebtedness of Walgreens. On December 31, 2014, Walgreens Boots Alliance fully and unconditionally guaranteed the outstanding notes on an unsecured and unsubordinated basis. The guarantee, for so long as it is in place, is an unsecured, unsubordinated debt obligation of Walgreens Boots Alliance and will rank equally in right of payment with all other unsecured and unsubordinated indebtedness of Walgreens Boots Alliance.

[6] Includes interest rate swap fair market value adjustments. See Note 8, Fair Value Measurements for additional fair value disclosures.