Debt (Nova Scotia Credit Agreement) (Narrative) (Details) - USD ($) $ in Millions		12 Months Ended
Sep. 29, 2017	Dec. 31, 2017
Nove Scotia Credit Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Initiation Date	Sep. 29, 2017
Debt Instrument, Face Amount	$ 2,250
Debt Instrument, Maturity Date Range, End		Jan. 31, 2018
Term of Loan		5 years
Credit agreement - minimum borrowing capacity		$ 0
Credit agreement - advances outstanding		$ 0
Ratio of net debt to EBITDA covenant		3.5 to 1
Credit agreement - base rate		• at a variable annual rate equal to (1) the highest of: (a) the base rate of Scotiabank, (b) 0.50% per annum above the federal funds rate, and (c) the ICE Benchmark Administration Limited Settlement Rate applicable to U.S. dollars for a period of one month plus 1.00% per annum, plus (2) an applicable margin (as set forth in the Nova Scotia Credit Agreement); or • at a rate equal to: (i) LIBOR for a period of three or six months, as applicable, plus (ii) an applicable margin (as set forth in the Nova Scotia Credit Agreement).
Nove Scotia Credit Agreement [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage		0.07%
Nove Scotia Credit Agreement [Member] \| Base Rate [Member] \| Additional Margin Upon Default [Member]
Debt Instrument [Line Items]
Credit agreement - basis spread of variable rate		2.00%
Tranche A Commitment [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Initiation Date	Sep. 29, 2017
Debt Instrument, Face Amount	$ 750
Debt Instrument, Maturity Date Range, End		Jan. 31, 2018
Term of Loan		5 years
Credit agreement - minimum borrowing capacity		$ 0
Credit agreement - advances outstanding		$ 0
Ratio of net debt to EBITDA covenant		3.5 to 1
Credit agreement - base rate		• at a variable annual rate equal to (1) the highest of: (a) the base rate of Scotiabank, (b) 0.50% per annum above the federal funds rate, and (c) the ICE Benchmark Administration Limited Settlement Rate applicable to U.S. dollars for a period of one month plus 1.00% per annum, plus (2) an applicable margin (as set forth in the Nova Scotia Credit Agreement); or • at a rate equal to: (i) LIBOR for a period of three or six months, as applicable, plus (ii) an applicable margin (as set forth in the Nova Scotia Credit Agreement).
Tranche A Commitment [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage		0.07%
Tranche A Commitment [Member] \| Base Rate [Member] \| Additional Margin Upon Default [Member]
Debt Instrument [Line Items]
Credit agreement - basis spread of variable rate		2.00%
Tranche B Commitment [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Initiation Date	Sep. 29, 2017
Debt Instrument, Face Amount	$ 750
Debt Instrument, Maturity Date Range, End		Jan. 31, 2018
Term of Loan		5 years
Credit agreement - minimum borrowing capacity		$ 0
Credit agreement - advances outstanding		$ 0
Ratio of net debt to EBITDA covenant		3.5 to 1
Credit agreement - base rate		• at a variable annual rate equal to (1) the highest of: (a) the base rate of Scotiabank, (b) 0.50% per annum above the federal funds rate, and (c) the ICE Benchmark Administration Limited Settlement Rate applicable to U.S. dollars for a period of one month plus 1.00% per annum, plus (2) an applicable margin (as set forth in the Nova Scotia Credit Agreement); or • at a rate equal to: (i) LIBOR for a period of three or six months, as applicable, plus (ii) an applicable margin (as set forth in the Nova Scotia Credit Agreement).
Tranche B Commitment [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage		0.07%
Tranche B Commitment [Member] \| Base Rate [Member] \| Additional Margin Upon Default [Member]
Debt Instrument [Line Items]
Credit agreement - basis spread of variable rate		2.00%
Tranche C Commitment [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Initiation Date	Sep. 29, 2017
Debt Instrument, Face Amount	$ 750
Debt Instrument, Maturity Date Range, End		Jan. 31, 2018
Term of Loan		5 years
Credit agreement - minimum borrowing capacity		$ 0
Credit agreement - advances outstanding		$ 0
Ratio of net debt to EBITDA covenant		3.5 to 1
Credit agreement - base rate		• at a variable annual rate equal to (1) the highest of: (a) the base rate of Scotiabank, (b) 0.50% per annum above the Federal funds rate, and (c) the ICE Benchmark Administration Limited Settlement Rate applicable to U.S. dollars for a period of one month plus 1.00% per annum, plus (2) an applicable margin (as set forth in the Nova Scotia Credit Agreement); or • at a rate equal to: (i) LIBOR for a period of three or six months, as applicable, plus (ii) an applicable margin (as set forth in the Nova Scotia Credit Agreement).
Tranche C Commitment [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage		0.07%
Tranche C Commitment [Member] \| Base Rate [Member] \| Additional Margin Upon Default [Member]
Debt Instrument [Line Items]
Credit agreement - basis spread of variable rate		2.00%

Line Of Credit Facility Covenant Debt Ratio

No definition available.

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- Definition

Minimum amount of borrowing capacity at the discretion of the company as debtor.

+ References

No definition available.

+ Details

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

+ References

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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- Definition

Date the credit facility first became available, in CCYY-MM-DD format.

+ References

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