Thailand Flooding (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	36 Months Ended	39 Months Ended
Jan. 02, 2015	Oct. 03, 2014	Jan. 02, 2015
Thailand Flooding [Abstract]
Insurance Recoveries And Other Cost Reimbursement	$ 37	$ 13	$ 50

Insurance recoveries and other cost reimbursements received related to the flood.

No definition available.

Name:	wdc_InsuranceRecoveriesAndOtherCostReimbursement
Namespace Prefix:	wdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration