Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Operating Revenue	$ 3,228	$ 3,552
Cost of revenue	1,871	2,059
Selling, administrative, and research and development expenses	560	611
Amortization and impairment of intangible assets	36	43
Operating Income	761	839
Interest expense	(51)	(63)
Other income (expense)	25	14
Income Before Taxes	735	790
Income Taxes	169	193
Net Income	$ 566	$ 597
Net Income Per Share:
Basic (in dollars per share)	$ 1.78	$ 1.82
Diluted (in dollars per share)	$ 1.77	$ 1.81
Shares of Common Stock Outstanding During the Period:
Average (in shares)	318.3	327.3
Average assuming dilution (in shares)	319.7	329.6

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.