Acquisition | Narrative (Details) $ in Millions	12 Months Ended
	Jan. 31, 2018 USD ($) shares
Business Acquisition [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	2,785,402
TS
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 1,000
Business Combination, Consideration Transferred	2,800
Payments to Acquire Businesses, Gross	2,500
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	247
Goodwill, Purchase Accounting Adjustments	229
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles	116
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets	22
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current Assets	19
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Liabilities	12
Business Acquisition, Goodwill and Intangibles, Expected Tax Deductible Amount	1,200
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	8,900
Trade Names [Member] | TS
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 44
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years
Customer Relationships [Member] | TS
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 875
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	14 years