Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Operating Revenue	$ 3,744	$ 3,471
Cost of revenue	2,181	2,003
Selling, administrative, and research and development expenses	612	608
Amortization and impairment of intangible assets	48	53
Operating Income	903	807
Interest expense	(66)	(64)
Other income (expense)	12	6
Income Before Taxes	849	749
Income Taxes	197	213
Net Income	$ 652	$ 536
Net Income Per Share:
Basic (in dollars per share)	$ 1.92	$ 1.55
Diluted (in dollars per share)	1.90	1.54
Cash Dividends Per Share:
Paid (in dollars per share)	0.78	0.65
Declared (in dollars per share)	$ 0.78	$ 0.65
Shares of Common Stock Outstanding During the Period:
Average (in shares)	340.2	346.2
Average assuming dilution (in shares)	342.8	349.0

Amortization and Impairment of Intangible Assets

No definition available.

Name:	itw_AmortizationandImpairmentofIntangibleAssets
Namespace Prefix:	itw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate total costs related to selling a firm's product and services, as well as all other general, administrative, and research and development expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

+ References

No definition available.