Recent Accounting Standards - Accounting impact (Details) $ in Millions	Dec. 30, 2017 USD ($) shares
New Accounting Pronouncement, Early Adoption [Line Items]
Decrease in income tax provision due to adoption of ASU No. 2016-9	$ 12.5
New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Decrease to the opening balance of retained earnings, Net of Tax	6.1
Decrease in income tax provision due to adoption of ASU No. 2016-9	$ 12.5
Increase to weighted average diluted shares outstanding | shares	123,470
Increase to the opening balance of retained earnings, net	$ 19.8