Income Taxes - Net operating loss and credit carryforwards (Details) $ in Millions	Dec. 30, 2017 USD ($)
No Expiration | Non-U.S.
Operating loss and credit carryforward
Net operating loss	$ 201
Expiration through 2036 | Non-U.S.
Operating loss and credit carryforward
Net operating loss	59
Expiration through 2036 | U.S.
Operating loss and credit carryforward
Net operating loss	269
Expiration through 2036 | State
Operating loss and credit carryforward
Net operating loss and tax credits, net of tax benefits	$ 290