Debt (Narrative) (Detail) $ in Millions | Apr. 23, 2018 | May 31, 2018 | Jun. 29, 2018USD ($)loan | Jun. 29, 2018USD ($)loan | May 15, 2018USD ($) | May 01, 2018USD ($) | Dec. 29, 2017USD ($) | Nov. 24, 2014USD ($) |
Senior Notes | 2023 Senior Notes, 4.15%, due June 2023 | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Principal | | | $ 300 | $ 300 | | | $ 0 | |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate | | | 4.15% | 4.15% | | | | |
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed | | | | 99.964% | | | | |
Debt Issuance Costs, Gross | | | $ 0.9 | $ 0.9 | | | | |
Senior Notes | 2028 Senior Notes, 4.9%, due June 2028 | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Principal | | | $ 600 | $ 600 | | | 0 | |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate | | | 4.90% | 4.90% | | | | |
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed | | | | 99.867% | | | | |
Debt Issuance Costs, Gross | | | $ 1.8 | $ 1.8 | | | | |
Senior Notes | 2024 Senior Notes, 4.75%, due December 2024 | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Principal | | | 400 | 400 | | | 400 | $ 400 |
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate | | | | | | | | 4.75% |
Debt Issuance Costs, Gross | | | 3 | 3 | | | | |
Revolving Credit Facility | Two Thousand Eighteen Interim Credit Facilities [Member] | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Repayments of Debt | | | 300 | | | | | |
Revolving Credit Facility | 2014 Credit Facility, floating rate, retired | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Line of Credit Facility, Fair Value of Amount Outstanding | | | $ 0 | 0 | | | 389 | |
Revolving Credit Facility | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Covenant Ratio - Minimum Interest Coverage | | | 3.50 | | | | | |
Covenant Ratio - Maximum Leverage | | | 3.50 | | | | | |
Covenant Ratio - Maximum Leverage At End of Fiscal Quarter If Viewpoint Acquisition Occurs And Three Fiscal Quarters Immediately Following Such Fiscal Quarter | | | 4.25 | | | | | |
Covenant Ratio - Maximum Leverage At End Of Each Next Two Fiscal Quarters Immediately Following Viewpoint Acquisition | | | 3.75 | | | | | |
Exceeding Cash Consideration For Material Acquisition As Defined | | | $ 100 | | | | | |
Covenant Ratio - Maximum Leverage At End Of Fiscal Quarter During Which Material Acquisition Occurs And Each Three Immediately Following Fiscal Quarters | | | 3.75 | | | | | |
Promissory Notes And Other Debt | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Promissory Notes and Other Debt, Current and Noncurrent | | | $ 1.3 | 1.3 | | | 1.2 | |
Promissory Notes And Other Notes, Noncurrent | | | 0.9 | 0.9 | | | 0.8 | |
Revolving Credit Facility | Uncommitted Facilities, floating rate | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Line of Credit Facility, Current Borrowing Capacity | | | $ 75 | $ 75 | | | | |
Number Of Revolving Loan Facilities | loan | | | 2 | 2 | | | | |
Short-term Debt | | | $ 0 | $ 0 | | | $ 128 | |
Short-term Debt, Weighted Average Interest Rate, at Point in Time | | | | | | | 2.24% | |
Revolving Credit Facility | Uncommitted Facility Two [Member] | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Line of Credit Facility, Current Borrowing Capacity | | | 75 | 75 | | | | |
Waterfall Holdings [Member] | Unsecured Bridge Term Loan [Member] | Bridge Loan [Member] | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Principal | | | 1,200 | 1,200 | | | | |
Line of Credit Facility, Current Borrowing Capacity | | | | | | $ 700 | | |
Line of Credit Facility, Periodic Payment, Interest | | | 5.8 | | | | | |
Debt Instrument, Term | 364 days | | | | | | | |
Waterfall Holdings [Member] | Unsecured Bridge Term Loan [Member] | Backstop Revolving Credit Facility In Case Of One Lender [Member] | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Principal | | | 1,000 | 1,000 | | | | |
JPMorgan Chase Bank, N.A. [Member] | Unsecured Debt [Member] | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Issuance Costs, Gross | | | 4.8 | 4.8 | | | | |
Line of Credit Facility, Current Borrowing Capacity | | | | | $ 1,750 | | | |
Line of Credit Facility, Fair Value of Amount Outstanding | | | $ 0 | $ 0 | | | | |
JPMorgan Chase Bank, N.A. [Member] | Revolving Credit Facility | Unsecured Debt [Member] | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Line of Credit Facility, Current Borrowing Capacity | | | | | 1,250 | | | |
Debt Instrument, Term | | 5 years | | | | | | |
JPMorgan Chase Bank, N.A. [Member] | Delayed Draw Term Loan [Member] | Unsecured Debt [Member] | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Line of Credit Facility, Current Borrowing Capacity | | | | | 500 | | | |
Debt Instrument, Term | | 3 years | | | | | | |
JPMorgan Chase Bank, N.A. [Member] | Additional Loan Facility [Member] | Unsecured Debt [Member] | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Line of Credit Facility, Current Borrowing Capacity | | | | | $ 500 | | | |
Federal Funds Effective Swap Rate [Member] | Revolving Credit Facility | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Credit facility, Variable Rate Basis Plus Percentage | | | 1.00% | | | | | |
Reserve Adjusted One Month LIBOR [Member] | Revolving Credit Facility | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | 0.50% | | | | | |
Maturity Period, Variable Rate | | | 1 month | | | | | |
Reserve Adjusted One Month LIBOR [Member] | Revolving Credit Facility | Minimum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | 0.00% | | | | | |
Reserve Adjusted One Month LIBOR [Member] | Revolving Credit Facility | Maximum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | 0.875% | | | | | |
Adjustment LIBOR Rate One, Two, Three Or Six Month Interest Periods [Member] | Revolving Credit Facility | Minimum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | 1.00% | | | | | |
Adjustment LIBOR Rate One, Two, Three Or Six Month Interest Periods [Member] | Revolving Credit Facility | Maximum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | 1.875% | | | | | |
Adjusted EURIBOR Rate, One, Two, Three Or Six Months Interest Periods [Member] | Revolving Credit Facility | Minimum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | 1.00% | | | | | |
Adjusted EURIBOR Rate, One, Two, Three Or Six Months Interest Periods [Member] | Revolving Credit Facility | Maximum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | 1.875% | | | | | |
EURIBOR Rate | Revolving Credit Facility | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
One Month Variable Interest Period | | | 1 month | | | | | |
Two Month Variable Interest Periods | | | 2 months | | | | | |
Three Month Variable Interest Periods | | | 3 months | | | | | |
Six Month Variable Interest Periods | | | 6 months | | | | | |
EURIBOR Rate | Revolving Credit Facility | Maximum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Interest Payable Periods On Borrowings | | | 3 months | | | | | |
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
One Month Variable Interest Period | | | 1 month | | | | | |
Two Month Variable Interest Periods | | | 2 months | | | | | |
Three Month Variable Interest Periods | | | 3 months | | | | | |
Six Month Variable Interest Periods | | | 6 months | | | | | |
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility | Maximum | 2018 Credit Facility | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | |
Interest Payable Periods On Borrowings | | | 3 months | | | | | |