Fair Value Measurements - Summary of Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2017	Jan. 01, 2017
Assets:
Estimated Fair Value	$ 920	$ 824
Debt securities in government sponsored entities [Member]
Assets:
Estimated Fair Value	67	34
Corporate debt securities [Member]
Assets:
Estimated Fair Value	421	476
U.S. Treasury securities [Member]
Assets:
Estimated Fair Value	432	314
Fair value, measurements, recurring [Member]
Assets:
Deferred compensation plan assets	35	31
Total assets measured at fair value	1,912	1,241
Liabilities:
Acquisition-related contingent consideration liabilities		4
Deferred compensation liability	33	29
Total liabilities measured at fair value	33	33
Fair value, measurements, recurring [Member] \| Debt securities in government sponsored entities [Member]
Assets:
Estimated Fair Value	67	34
Fair value, measurements, recurring [Member] \| Corporate debt securities [Member]
Assets:
Estimated Fair Value	421	476
Fair value, measurements, recurring [Member] \| U.S. Treasury securities [Member]
Assets:
Estimated Fair Value	432	314
Fair value, measurements, recurring [Member] \| Money market funds (cash equivalent) [Member]
Assets:
Money market funds (cash equivalent)	957	386
Fair value, measurements, recurring [Member] \| Level 1 [Member]
Assets:
Total assets measured at fair value	1,389	700
Fair value, measurements, recurring [Member] \| Level 1 [Member] \| U.S. Treasury securities [Member]
Assets:
Estimated Fair Value	432	314
Fair value, measurements, recurring [Member] \| Level 1 [Member] \| Money market funds (cash equivalent) [Member]
Assets:
Money market funds (cash equivalent)	957	386
Fair value, measurements, recurring [Member] \| Level 2 [Member]
Assets:
Deferred compensation plan assets	35	31
Total assets measured at fair value	523	541
Liabilities:
Deferred compensation liability	33	29
Total liabilities measured at fair value	33	29
Fair value, measurements, recurring [Member] \| Level 2 [Member] \| Debt securities in government sponsored entities [Member]
Assets:
Estimated Fair Value	67	34
Fair value, measurements, recurring [Member] \| Level 2 [Member] \| Corporate debt securities [Member]
Assets:
Estimated Fair Value	$ 421	476
Fair value, measurements, recurring [Member] \| Level 3 [Member]
Liabilities:
Acquisition-related contingent consideration liabilities		4
Total liabilities measured at fair value		$ 4

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Amount of liability recognized arising from contingent consideration in a business combination.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value of financial and nonfinancial obligations.

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