Segment Information - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2021 USD ($)	Jan. 31, 2020 USD ($)	Jan. 31, 2021 USD ($) segment	Jan. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Total operating income (loss)	$ (25)	$ 270	$ 184	$ 280
International total net revenue as a percentage of total (less than)	6.00%			5.00%
Segment Reconciling Items
Segment Reporting Information [Line Items]
Other corporate expenses	$ (442)	(440)	(874)	$ (866)
Segment Reconciling Items | Segment Reclass | Small Business & Self-Employed
Segment Reporting Information [Line Items]
Other corporate expenses		(45)		(88)
Segment Reconciling Items | Segment Reclass | Consumer
Segment Reporting Information [Line Items]
Other corporate expenses		(28)		(53)
Segment Reconciling Items | Segment Reclass | ProConnect
Segment Reporting Information [Line Items]
Other corporate expenses		(4)		(7)
Operating Segments
Segment Reporting Information [Line Items]
Total operating income (loss)	647	824	1,408	1,379
Operating Segments | Small Business & Self-Employed
Segment Reporting Information [Line Items]
Total operating income (loss)	592	447	1,359	1,040
Operating Segments | Consumer
Segment Reporting Information [Line Items]
Total operating income (loss)	(155)	191	(151)	171
Operating Segments | ProConnect
Segment Reporting Information [Line Items]
Total operating income (loss)	$ 172	186	$ 162	168
Operating Segments | Segment Reclass | Small Business & Self-Employed
Segment Reporting Information [Line Items]
Total operating income (loss)		45		88
Operating Segments | Segment Reclass | Consumer
Segment Reporting Information [Line Items]
Total operating income (loss)		28		53
Operating Segments | Segment Reclass | ProConnect
Segment Reporting Information [Line Items]
Total operating income (loss)		$ 4		$ 7