Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Operating Revenue	$ 2,564	$ 3,609	$ 5,792	$ 7,161
Cost of revenue	1,594	2,099	3,465	4,158
Selling, administrative, and research and development expenses	486	598	1,046	1,209
Amortization and impairment of intangible assets	35	41	71	84
Operating Income	449	871	1,210	1,710
Interest expense	(51)	(55)	(102)	(118)
Other income (expense)	8	9	33	23
Income Before Taxes	406	825	1,141	1,615
Income Taxes	87	202	256	395
Net Income	$ 319	$ 623	$ 885	$ 1,220
Net Income Per Share:
Basic (in dollars per share)	$ 1.01	$ 1.92	$ 2.79	$ 3.74
Diluted (in dollars per share)	$ 1.01	$ 1.91	$ 2.78	$ 3.72
Shares of Common Stock Outstanding During the Period:
Average (in shares)	316.1	324.8	317.2	326.0
Average assuming dilution (in shares)	317.4	326.6	318.6	327.9

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.